In preparation for removing the strlcat API[1],
replace the string concatenation logic with a struct seq_buf,
which tracks the current position and the remaining space internally.
Use seq_buf_str() to NUL-terminate before passing to early_enable_events().
Link: https://github.com/KSPP/linux/issues/370 [1]
Link: https://patch.msgid.link/20260713045249.69942-1-woradorn.laon@gmail.com
Signed-off-by: Woradorn Laodhanadhaworn <woradorn.laon@gmail.com>
[ Moved placement of #include <linux/seq_buf.h> ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Replace strcpy() with strscpy() in __trace_find_cmdline() for
consistency with the existing strscpy() call in the same function,
and to avoid potential buffer overflow as flagged by the Kernel
Self Protection Project.
Link: https://patch.msgid.link/20260705173648.5418-1-posheng.lin.tw@gmail.com
Signed-off-by: Po-Sheng Lin <posheng.lin.tw@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Currently on boot up and when modules are loaded, the trace event
infrastructure will examine the TP_printk's of every event looking to see
if it dereferences pointers on the ring buffer via printk formats like
"%pB" and such. What it doesn't do is check if the arguments themselves
do a dereference from a pointer.
This was brought with a fix[1] to the fsl_edma event that had in the
arguments of the TP_printk(): "__entry->edma->membase"
The __entry->edma is a pointer saved in the ring buffer. The dereference
from TP_printk() happens when the user reads the "trace" file which can be
seconds, minutes, hours, days, weeks, or even months later! There is no
guarantee that the __entry->edma pointer will still be pointing to what it
was when it was recorded, and could crash the kernel when a user reads the
event.
Add logic to the test_event_printk() that also checks for this case and
warn if the event dereferences a pointer from the ring buffer.
[1] https://lore.kernel.org/all/20260630200022.1826420-1-martin@kaiser.cx/
Link: https://patch.msgid.link/20260630184836.74d477b6@gandalf.local.home
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Reviewed-by: Martin Kaiser <martin@kaiser.cx>
Reviewed-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
preemptirq_delay_test accepts cpu_affinity as a module parameter and,
when it is non-negative, writes that CPU directly into a temporary
cpumask from the worker thread. Values outside nr_cpu_ids can set a bit
outside the allocated cpumask before the test reports a normal affinity
error.
Validate the requested CPU in preemptirq_delay_run() before setting it
in the temporary cpumask. Invalid affinity requests are reported by
the test thread and skipped before cpumask_set_cpu() can touch an
out-of-range bit.
Link: https://patch.msgid.link/20260628131021.2208632.6a5c6c959813.preemptirq-delay-test-invalid-cpu-affinity@trailofbits.com
Assisted-by: Codex:gpt-5.5-cyber-preview
Signed-off-by: Samuel Moelius <sam.moelius@trailofbits.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
A single closing curly bracket should be put into a trace sequence buffer.
Thus use the corresponding function “trace_seq_putc”.
The source code was transformed by using the Coccinelle software.
Link: https://patch.msgid.link/d215fa89-9a62-4067-86ec-833290f35c80@web.de
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
A single string should be put into a sequence within a loop.
Thus use the corresponding function “seq_puts” for one selected call.
The source code was transformed by using the Coccinelle software.
Link: https://patch.msgid.link/1cf327f0-49a6-477f-a06f-2b22a167db24@web.de
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Single characters should be put into a sequence. Thus use the corresponding
function “seq_putc” for selected calls.
The source code was transformed by using the Coccinelle software.
Link: https://patch.msgid.link/6bcaa4da-05c6-4097-90f5-3969f8a1dfbc@web.de
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
expr_str() allocates a fixed MAX_FILTER_STR_VAL buffer and then builds
expression names with a series of raw strcat() appends. Nested operands,
constants, field flags, and generated field names can push the rendered
string past that fixed limit before the name is attached to the hist
field.
Build expression strings with seq_buf and return -E2BIG when the
rendered name would exceed MAX_FILTER_STR_VAL. This keeps the existing
tracing-side limit while replacing the raw append logic with bounded
construction.
Link: https://patch.msgid.link/20260611055945.22348-4-pengpeng@iscas.ac.cn
Signed-off-by: Pengpeng Hou <pengpeng@iscas.ac.cn>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
expr_str() currently reports all failure cases as NULL, so callers cannot
distinguish invalid recursion depth from allocation failure or later
string construction errors.
Return ERR_PTR()-encoded errors from expr_str() and make parse_unary()
and parse_expr() propagate them. Clear expr->name before destroying the
hist field so the error pointer is not freed as a string.
Link: https://patch.msgid.link/20260611055945.22348-3-pengpeng@iscas.ac.cn
Signed-off-by: Pengpeng Hou <pengpeng@iscas.ac.cn>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
expr_str() allocates a temporary expression buffer and manually frees it
on some error paths.
Convert the buffer to __free(kfree) and return it with return_ptr() on
success. This keeps ownership handling separate from the later ERR_PTR()
conversion and string-bound change.
Link: https://patch.msgid.link/20260611055945.22348-2-pengpeng@iscas.ac.cn
Signed-off-by: Pengpeng Hou <pengpeng@iscas.ac.cn>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The HIST_FIELD_FL_CONST path uses the fixed "u64" type string.
Point hist_field->type directly to the string literal, matching the
HIST_FIELD_FL_HITCOUNT path. The release path already uses kfree_const(),
so no duplication is needed.
Link: https://patch.msgid.link/20260527023450.2137639-1-pengyu@kylinos.cn
Signed-off-by: Yu Peng <pengyu@kylinos.cn>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Add events/<sys>/<event>/btf_ids, a per-template file that exposes
the BTF ids resolve_btfids fills in for each tracepoint:
btf_obj_id BTF object owning the ids below
raw_btf_id FUNC_PROTO of __bpf_trace_<call> (named args), consumed
by raw_tp / tp_btf BPF programs
tp_btf_id trace_event_raw_<call> ring-buffer record, consumed by
classic BPF_PROG_TYPE_TRACEPOINT programs
DECLARE_EVENT_CLASS now emits a 2-entry BTF_ID_LIST (FUNC __bpf_trace_*
and STRUCT trace_event_raw_*) and stores the pointer in
trace_event_class.
Per-syscall events under syscalls/ share the handcrafted classes
event_class_syscall_{enter,exit} instead of going through
DECLARE_EVENT_CLASS. Wire those classes to the BTF id lists
generated for sys_enter / sys_exit so all ~700 per-syscall
events expose the shared dispatcher prototype and record.
The per-syscall events do not own their own tracepoint
(they share sys_enter/sys_exit), so raw_btf_id is reported as 0
on those events; the meaningful raw_btf_id is exposed on
raw_syscalls/sys_{enter,exit}/btf_ids where raw_tp / tp_btf
programs can actually attach.
Link: https://patch.msgid.link/20260518-generic_tracepoint-v2-2-b755a5cf67bb@meta.com
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Drop the static qualifier and add prototypes to <linux/btf.h> so the
tracing core can look up module BTF and translate ids stored by
resolve_btfids (which are local to a module's split BTF) into the
runtime ids used by the kernel.
Used by the upcoming events/<sys>/<event>/btf_ids tracefs interface.
Link: https://patch.msgid.link/20260518-generic_tracepoint-v2-1-b755a5cf67bb@meta.com
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
- Move rb_desc->nr_page_va before updating dynamic array
The rb_descr->page_va is a dynamic array counted by nr_page_va. But the
updating of the page_va[] is done before the nr_page_va is incremented
causing a build with CONFIG_UBSAN_BOUNDS to flag it as an overflow.
Move the increment of the counted by value before the array element is
updated.
- Propagate errors from remote event bulk updates
The return value of trace_remote_enable_event() was not being checked by
remote_events_dir_enable_write() where it would silently fail. Have it
check the return value and propagate that back up to user space.
- Fix resource leak on mmiotrace trace_pipe close
The mmiotrace tracer was created in 2008 before the trace_pipe had a close
callback to allow tracers to do clean up from trace_pipe open. The
trace_pipe close cleanup callback was added in 2009 but the mmiotrace
tracer was not updated. It had a hack to do the cleanup in the read call,
where it may leak if user space did not read the entire buffer.
Add a callback to mmiotrace trace_pipe close do to the cleanup properly.
- Fix a possible NULL pointer dereference in the mmiotrace tracer
If the mmio_pipe_open() fails to find a PCI device, it will set the
hiter->dev pointer to NULL. The read function will blindly dereference
that pointer. Fix the read call to check to see if that pointer is
populated before dereferencing it.
- Fix union collision of module and refcnt for dynamic events
In 'struct trace_event_call', the 'module' pointer and the 'refcnt' atomic
variable share the same memory space in a union. The filter on module
logic only checked if the 'module' was set to determine if the event
belonged to the module. As dynamic events are always builtin, it doesn't
need the 'module' field of the structure and used a refcount. But the
module filtering logic would then mistaken these dynamic events as a
module and call module_name(event->module) on it.
Add a check to see if the event is a dynamic event and if so, do not check
it for being part of the given module.
- Reset the top level buffer in selftests before running instances
The ftracetest selftest initializes each instance before executing the
tests. But it does not reset the top level buffer. Dynamic events are only
added and removed by the top level so any left over dynamic events will
not be removed by the reset in the instances.
Left over dynamic events can cause the tests to incorrectly fail. Reset
the top level buffer before running the instances.
- Make the context_switch counter 64 bit
The code to read user space for a system call trace event or for a
trace_marker will disable migration, enable preemption, read user space
into a per CPU buffer, disable preemption and enable migration again.
It checks if the per CPU context switch counter to see if it changed, and
if it did not, it would know that the per CPU buffer was not touched by
another task.
But the save counter was 32 bit and it would compare it to the 64 bit
context_switch variable. A long running system could have the
context_switch variable greater that 1<<32 in which case the compare will
always fail. The compare will promote the 32 bit int saved value to 64 bit
and compare it to the full 64 bit counter. Since the top 32 bits of the
saved value was zero, it would never match.
- Fix a use-after-free of the event_enable trigger
The event_enable trigger allows for enabling one event when another event
is triggered. When the trigger is removed, it must go through a
synchronization phase to make sure it is not triggered again. The trigger
itself is delayed by the "bulk delay" logic that was recently added.
But the code that frees the event_enable data used to rely on the trigger
code to do the synchronization. Now that the code uses the call RCU
functions (and a workqueue), that delay no longer is there.
Add a callback private_data_free() function that allows triggers to clean
up data after the synchronization phase has completed.
- Move the module_ref counter into the delay callback
Since an event of the event_enable trigger can enable an event for a
module, it ups the module ref count for that event's module. This prevents
the event from trying to enable an event that no longer exists and cause a
use-after-free bug.
The ref counter was set back down when the trigger was removed but not
after thy synchronization phase. This could lead to the module data being
accessed after module was unloaded.
Move the module ref decrement into the private_data_free() callback of the
event_enable trigger.
- Add mutex to protect parser in ftrace filtering
The set_ftrace_filter file uses a parsing descriptor that is allocated at
open and modified by writes. If multiple threads were to write to the
descriptor at the same time, it can corrupt the parser.
Add a mutex around the modifications of the parser descriptor.
- Fix possible corruption in perf syscall tracing
The perf system call trace events can now read user space. To do so, the
reads of user space enable preemption and disables it again. During this
time that preemption is enabled, the task can migrate. The perf event list
head is assigned via a per CPU pointer. It is done before the user space
part is called. If the user space reading migrates the task to another
CPU, then the head pointer is no longer valid.
Re-assign the head pointer after the reading of user space to keep it
using the correct data.
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Merge tag 'trace-v7.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing fixes from Steven Rostedt:
- Move rb_desc->nr_page_va before updating dynamic array
The rb_descr->page_va is a dynamic array counted by nr_page_va. But
the updating of the page_va[] is done before the nr_page_va is
incremented causing a build with CONFIG_UBSAN_BOUNDS to flag it as an
overflow.
Move the increment of the counted by value before the array element
is updated.
- Propagate errors from remote event bulk updates
The return value of trace_remote_enable_event() was not being checked
by remote_events_dir_enable_write() where it would silently fail.
Have it check the return value and propagate that back up to user
space.
- Fix resource leak on mmiotrace trace_pipe close
The mmiotrace tracer was created in 2008 before the trace_pipe had a
close callback to allow tracers to do clean up from trace_pipe open.
The trace_pipe close cleanup callback was added in 2009 but the
mmiotrace tracer was not updated. It had a hack to do the cleanup in
the read call, where it may leak if user space did not read the
entire buffer.
Add a callback to mmiotrace trace_pipe close do to the cleanup
properly.
- Fix a possible NULL pointer dereference in the mmiotrace tracer
If the mmio_pipe_open() fails to find a PCI device, it will set the
hiter->dev pointer to NULL. The read function will blindly
dereference that pointer. Fix the read call to check to see if that
pointer is populated before dereferencing it.
- Fix union collision of module and refcnt for dynamic events
In 'struct trace_event_call', the 'module' pointer and the 'refcnt'
atomic variable share the same memory space in a union. The filter on
module logic only checked if the 'module' was set to determine if the
event belonged to the module. As dynamic events are always builtin,
it doesn't need the 'module' field of the structure and used a
refcount. But the module filtering logic would then mistaken these
dynamic events as a module and call module_name(event->module) on it.
Add a check to see if the event is a dynamic event and if so, do not
check it for being part of the given module.
- Reset the top level buffer in selftests before running instances
The ftracetest selftest initializes each instance before executing
the tests. But it does not reset the top level buffer. Dynamic events
are only added and removed by the top level so any left over dynamic
events will not be removed by the reset in the instances.
Left over dynamic events can cause the tests to incorrectly fail.
Reset the top level buffer before running the instances.
- Make the context_switch counter 64 bit
The code to read user space for a system call trace event or for a
trace_marker will disable migration, enable preemption, read user
space into a per CPU buffer, disable preemption and enable migration
again. It checks if the per CPU context switch counter to see if it
changed, and if it did not, it would know that the per CPU buffer was
not touched by another task.
But the save counter was 32 bit and it would compare it to the 64 bit
context_switch variable. A long running system could have the
context_switch variable greater that 1<<32 in which case the compare
will always fail. The compare will promote the 32 bit int saved value
to 64 bit and compare it to the full 64 bit counter. Since the top 32
bits of the saved value was zero, it would never match.
- Fix a use-after-free of the event_enable trigger
The event_enable trigger allows for enabling one event when another
event is triggered. When the trigger is removed, it must go through a
synchronization phase to make sure it is not triggered again. The
trigger itself is delayed by the "bulk delay" logic that was recently
added. But the code that frees the event_enable data used to rely on
the trigger code to do the synchronization. Now that the code uses
the call RCU functions (and a workqueue), that delay no longer is
there.
Add a callback private_data_free() function that allows triggers to
clean up data after the synchronization phase has completed.
- Move the module_ref counter into the delay callback
Since an event of the event_enable trigger can enable an event for a
module, it ups the module ref count for that event's module. This
prevents the event from trying to enable an event that no longer
exists and cause a use-after-free bug.
The ref counter was set back down when the trigger was removed but
not after thy synchronization phase. This could lead to the module
data being accessed after module was unloaded.
Move the module ref decrement into the private_data_free() callback
of the event_enable trigger.
- Add mutex to protect parser in ftrace filtering
The set_ftrace_filter file uses a parsing descriptor that is
allocated at open and modified by writes. If multiple threads were to
write to the descriptor at the same time, it can corrupt the parser.
Add a mutex around the modifications of the parser descriptor.
- Fix possible corruption in perf syscall tracing
The perf system call trace events can now read user space. To do so,
the reads of user space enable preemption and disables it again.
During this time that preemption is enabled, the task can migrate.
The perf event list head is assigned via a per CPU pointer. It is
done before the user space part is called. If the user space reading
migrates the task to another CPU, then the head pointer is no longer
valid.
Re-assign the head pointer after the reading of user space to keep it
using the correct data.
* tag 'trace-v7.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracing: perf: Fix stale head for perf syscall tracing
ftrace: Add global mutex to serialize trace_parser access
tracing: Delay module ref count for "enable_event" trigger
tracing: Fix use-after-free freeing trigger private data
tracing: Fix context switch counter truncation
selftests/ftrace: Reset triggers at top level before instance loop
tracing: Fix union collision of module and refcnt for dynamic events
tracing: Fix mmiotrace possible NULL dereferencing of hiter->dev
tracing: Fix resource leak on mmiotrace trace_pipe close
tracing: Propagate errors from remote event bulk updates
tracing/remotes: Fix page_va[] access before counter update in trace_remote_alloc_buffer()
In ftrace, the trace_parser structure is allocated and initialized when
a trace file is opened, and is subsequently used across write and release
handlers to parse user input.
The affected handler paths and their specific functions are:
- Open paths: ftrace_regex_open(), ftrace_graph_open()
- Write paths: ftrace_regex_write(), ftrace_graph_write()
- Release paths: ftrace_regex_release(), ftrace_graph_release()
If userspace opens a trace file descriptor and shares it across multiple
threads, concurrent write calls will race on the parser's internal state,
specifically the 'idx', 'cont', and 'buffer' fields, leading to corrupted
input or undefined behavior.
Fix this by adding a global mutex, parser_lock, to serialize all access
to trace_parser across write and release paths, preventing concurrent
corruption of parser state.
Fixes: e704eff3ff ("ftrace: Have set_graph_function handle multiple functions in one write")
Fixes: 689fd8b65d ("tracing: trace parser support for function and graph")
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260725024721.1983675-1-wutengda@huaweicloud.com
Signed-off-by: Tengda Wu <wutengda@huaweicloud.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
- Fix tcp_bpf_sendmsg() error path mistaking a concurrently-freed
sk_psock->cork for the local temporary message and freeing it
again. (Chengfeng Ye)
- Reject passing scalar NULL to nonnull arg of a global subprog.
Previously the verifier did not account for the cases directly
passing scalars to a global subprog, e.g.: 'global_func(0);'
would pass even if 'global_func' argument was marked nonnull.
(Amery Hung)
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
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Merge tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Pull bpf fixes from Eduard Zingerman:
- Fix tcp_bpf_sendmsg() error path mistaking a concurrently-freed
sk_psock->cork for the local temporary message and freeing it again
(Chengfeng Ye)
- Reject passing scalar NULL to nonnull arg of a global subprog.
Previously the verifier did not account for the cases directly
passing scalars to a global subprog, e.g.: 'global_func(0);' would
pass even if 'global_func' argument was marked nonnull (Amery Hung)
* tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
bpf, sockmap: Fix cork use-after-free in tcp_bpf_sendmsg()
selftests/bpf: Test passing scalar NULL to nonnull global subprog
bpf: Reject passing scalar NULL to nonnull arg of a global subprog
Triggers are now delayed from freeing, but can still be triggered until
after the RCU grace period has ended. The freeing of the enable_event data
is put into the private_data_free() callback, but the put of the module
refcount is done immediately.
It is possible that if a module is removed that has an event that would
enable (or disable) it is still active, it can read the data of the module
after it is removed causing a use-after-free bug.
Move the trace_event_put_ref() that releases the module into the delayed
callback so that the module can not be removed until any reference to its
events are finished.
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260724132415.1b5005db@gandalf.local.home
Reported-by: Sashiko <sashiko-bot@kernel.org>
Link: https://sashiko.dev/#/patchset/20260724030523.19081-1-devnexen%40gmail.com
Fixes: 61d445af0a ("tracing: Add bulk garbage collection of freeing event_trigger_data")
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Commit 61d445af0a ("tracing: Add bulk garbage collection of freeing
event_trigger_data") moved the kfree() of event_trigger_data to a kthread
that runs tracepoint_synchronize_unregister() before freeing. That removed
the synchronization the trigger .free callbacks used to get implicitly and
inline from trigger_data_free().
event_hist_trigger_free(), event_hist_trigger_named_free() and
event_enable_trigger_free() free their satellite data (hist_data, cmd_ops,
enable_data) right after trigger_data_free() returns. With the
synchronization now deferred to the kthread, a concurrent tracepoint
handler can still reach that data through the list_del_rcu()'d trigger,
causing a use-after-free.
The histogram teardown must stay synchronous: remove_hist_vars() and
unregister_field_var_hists() have to detach a synthetic event from the
histogram before the trigger-removal write returns, otherwise a following
command races in and the synthetic-event removal fails with -EBUSY, as the
trigger-synthetic-eprobe.tc selftest catches. Make those callbacks wait
with the correct barrier - tracepoint_synchronize_unregister(), matching
the free kthread - before freeing.
The enable trigger has no such synchronous requirement, and a blocking
synchronize there would re-serialize the path that commit deliberately
deferred. Give it an optional private_data_free() callback that the free
kthread runs after its grace period, and free enable_data from there.
Link: https://patch.msgid.link/20260724030523.19081-1-devnexen@gmail.com
Suggested-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Fixes: 61d445af0a ("tracing: Add bulk garbage collection of freeing event_trigger_data")
Signed-off-by: David Carlier <devnexen@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
trace_user_fault_read() samples nr_context_switches_cpu() before enabling
preemption and retries the user copy if the counter changes. The helper
returns unsigned long long because rq->nr_switches is u64, but the saved
value is unsigned int.
Once a CPU has performed 2^32 context switches, assigning the counter to
cnt discards its upper bits. The comparison after the copy promotes cnt
back to unsigned long long, but the lost bits remain zero, so it reports a
change even when the task was never scheduled out. Every retry then fails
the same way until the 100-try guard warns and the user copy is abandoned.
This affects long-running systems and workloads with high context-switch
rates. A CPU switching 1,000 times per second takes about 50 days.
Store the sampled count in unsigned long long so the full value is
preserved.
Cc: stable@vger.kernel.org
Fixes: 64cf7d058a ("tracing: Have trace_marker use per-cpu data to read user space")
Link: https://patch.msgid.link/20260717173252.3431565-1-usama.arif@linux.dev
Reported-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Usama Arif <usama.arif@linux.dev>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
In 'struct trace_event_call', the 'module' pointer and the 'refcnt'
atomic variable share the same memory space in a union. For dynamic
events, the union member is 'refcnt', which acts as an active
reference counter.
When a dynamic event (such as kprobe, uprobe, fprobe, eprobe, or
wprobe) has a non-zero reference count (e.g. due to active event
triggers or perf attachments), its 'call->module' evaluates to a
small non-zero integer instead of NULL.
When filtering or setting events for a specific module (e.g., writing
':mod:<module>' to 'set_event'), the code in
'__ftrace_set_clr_event_nolock()' and 'update_event_fields()' reads
'call->module' directly without checking whether the event is dynamic.
This causes the kernel to treat the small integer (refcnt) as a
'struct module' pointer, leading to a NULL/invalid pointer dereference
(Oops) when dereferencing the module name.
Fix this by ensuring that the 'TRACE_EVENT_FL_DYNAMIC' flag is checked
before treating 'call->module' as a valid pointer in these code paths.
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/178425670947.84440.11344393611899824907.stgit@devnote2
Fixes: 4c86bc531e ("tracing: Add :mod: command to enabled module events")
Assisted-by: Antigravity:gemini-3.5-flash
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
A global subprogram argument tagged __arg_nonnull is set up as a
non-nullable PTR_TO_MEM. However the verifier does not check against a
scalar NULL, leading to real NULL pointer dereference. Reject it as
well.
Fixes: 94e1c70a34 ("bpf: support 'arg:xxx' btf_decl_tag-based hints for global subprog args")
Signed-off-by: Amery Hung <ameryhung@gmail.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://patch.msgid.link/20260723221815.367797-1-ameryhung@gmail.com
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
The mmiotrace tracer was added May 12th 2008. At that time, resources
created in pipe_open() could not be freed because there was not
pipe_close function pointer of the tracer. The pipe_close function pointer
was added in December 7th, 2009, but the mmiotrace tracer was not updated.
mmio_pipe_open() allocates a header_iter and takes a pci_dev reference
when trace_pipe is opened. mmio_close() frees them, but it was only
wired to the tracer's .close callback.
tracing_release_pipe() invokes .pipe_close, not .close, when the
trace_pipe file is released. As a result, closing trace_pipe with the
mmiotrace tracer active leaked the header_iter allocation and left a
stale pci_dev reference.
Set .pipe_close to mmio_close, matching how function_graph wires both
callbacks to the same handler.
Note, if the trace_pipe is read to completion, it will clean up the
resources, but if one were to run:
# head -n 1 /sys/kernel/tracing/trace_pipe
VERSION 20070824
Over and over again, it would trigger a massive leak.
Cc: stable@vger.kernel.org
Fixes: c521efd170 ("tracing: Add pipe_close interface)
Link: https://patch.msgid.link/20260715143604.14481-1-gaikwad.dcg@gmail.com
Signed-off-by: deepakraog <gaikwad.dcg@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
remote_events_dir_enable_write() ignores the return value from
trace_remote_enable_event(). If a remote rejects an event state change,
the write therefore reports success even though the affected event remains
in its previous state.
Keep trying all events, but retain and return the first error. This matches
__ftrace_set_clr_event_nolock(), which permits partial updates while
notifying userspace when an operation fails.
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260715074455.3897-1-liu.yun@linux.dev
Fixes: 775cb093bc ("tracing: Add events/ root files to trace remotes")
Assisted-by: Codex:gpt-5.6-sol
Signed-off-by: Jackie Liu <liuyun01@kylinos.cn>
Reviewed-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
page_va[] is annotated __counted_by(nr_page_va), so nr_page_va must
cover an index before that element is accessed. The allocation loop
writes page_va[id] while nr_page_va is still id and increments it only
afterwards, so every write is one element past the declared count.
The store is out of bounds with respect to the annotation: a build with
CONFIG_UBSAN_BOUNDS on a toolchain that honours __counted_by
(clang >= 20.1, gcc >= 15.1) flags it as an array-index overflow.
Increment nr_page_va before writing the element it now covers. A failed
allocation then leaves the slot counted but NULL; the error path frees
it with free_page(0), which is a no-op.
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260713072823.2668323-1-fuad.tabba@linux.dev
Fixes: 96e43537af ("tracing: Introduce trace remotes")
Signed-off-by: Fuad Tabba <fuad.tabba@linux.dev>
Reviewed-by: Vincent Donnefort <vdonnefort@google.com>
Tested-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Commit b0473dcd4b ("smp: Improve smp_call_function_single()
CSD-lock diagnostics") changed smp_call_function_single() so that,
when CSD lock debugging is enabled, async !wait calls use the
destination CPU csd_data. That improves diagnostics, but it also removes
the single-writer property that made the old csd_lock() safe: multiple
CPUs can now prepare the same destination CPU CSD concurrently.
csd_lock() currently waits for CSD_FLAG_LOCK to clear and then sets the
bit with a non-atomic read-modify-write. Two senders can both see an
unlocked CSD, set the bit, overwrite the callback fields, and enqueue
the same llist node. Re-adding a node that is already the queue head can
make node->next point to itself, leaving the target CPU stuck walking
call_single_queue. Later synchronous work, such as a TLB shootdown, can
then remain queued and trigger soft-lockup warnings or panics.
Keep the single csd_lock() implementation, but when CSD lock debugging is
enabled, acquire CSD_FLAG_LOCK with try_cmpxchg_acquire(). This makes the
destination CPU CSD a real atomic lock in the only configuration where it
can be shared by multiple remote senders, while preserving the existing
non-debug fast path.
Fixes: b0473dcd4b ("smp: Improve smp_call_function_single() CSD-lock diagnostics")
Signed-off-by: Chuyi Zhou <zhouchuyi@bytedance.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Link: https://patch.msgid.link/20260716004539.13983-2-paulmck@kernel.org
Commit b0473dcd4b ("smp: Improve smp_call_function_single()
CSD-lock diagnostics") made smp_call_function_single() use the destination
CPU's csd_data when CSD lock debugging is enabled. That lets the debug code
associate a stuck CSD lock with the target CPU, but it also means the CPU
argument is used in per_cpu_ptr() before generic_exec_single() has a chance
to validate it.
This becomes unsafe when smp_call_function_any() cannot find an online CPU
in the supplied mask. In that case the selected CPU can be nr_cpu_ids, and
the !wait path calls get_single_csd_data(cpu) before generic_exec_single()
returns -ENXIO. With csdlock_debug_enabled set, that indexes the per-CPU
offset array with an invalid CPU number.
Use the destination CPU's csd_data only when the CPU number is within
nr_cpu_ids. For invalid CPU numbers, fall back to the local CPU's csd_data
and let generic_exec_single() perform the existing validation and return
-ENXIO.
Fixes: b0473dcd4b ("smp: Improve smp_call_function_single() CSD-lock diagnostics")
Signed-off-by: Chuyi Zhou <zhouchuyi@bytedance.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Acked-by: Muchun Song <muchun.song@linux.dev>
Link: https://patch.msgid.link/20260716004539.13983-1-paulmck@kernel.org
* Fix validation of LIVEUPDATE_SESSION_GET_NAME ioctl argument caused by a
wrong resolution of a merge conflict during the last merge window
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Merge tag 'liveupdate-fixes-2026-07-22' of git://git.kernel.org/pub/scm/linux/kernel/git/liveupdate/linux
Pull liveupdate fix from Mike Rapoport:
- Fix validation of LIVEUPDATE_SESSION_GET_NAME ioctl argument caused
by a wrong resolution of a merge conflict during the last merge
window
* tag 'liveupdate-fixes-2026-07-22' of git://git.kernel.org/pub/scm/linux/kernel/git/liveupdate/linux:
liveupdate: fix GET_NAME ioctl argument validation
eprobe_dyn_event_match() checks if the target event system in argv[0]
matches ep->event_system using strncmp(ep->event_system, argv[0], len).
However, if ep->event_system is longer than len (e.g. "eprobes" vs
"ep/event"), strncmp() still returns 0 because the first len characters
match.
Check that ep->event_system[len] is '\0' to ensure exact system name
matching.
Link: https://lore.kernel.org/all/178454235856.290363.14872590900774231133.stgit@devnote2/
Fixes: 7d5fda1c84 ("tracing: Fix event probe removal from dynamic events")
Cc: stable@vger.kernel.org
Assisted-by: Antigravity:gemini-3.5-flash
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
In __set_print_fmt(), LEN_OR_ZERO is defined as (len ? len - pos : 0).
If len is non-zero but smaller than pos, len - pos evaluates to a negative
integer. When passed as a size argument to snprintf(), this negative value
is cast to a large unsigned size_t, bypassing buffer size limits.
Ensure len > pos before subtracting to avoid integer underflow.
Link: https://lore.kernel.org/all/178454234934.290363.15247317871499514139.stgit@devnote2/
Fixes: 5bf652aaf4 ("tracing/probes: Integrate duplicate set_print_fmt()")
Cc: stable@vger.kernel.org
Assisted-by: Antigravity:gemini-3.5-flash
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
If trace_probe_log.argc is 0 in __trace_probe_log_err(), the loop
constructing the command string will not execute and p will remain equal to
command. Writing to *(p - 1) will cause an out-of-bounds access before
command. This should not happen, but better to be treated.
Reject if trace_probe_log.argc is 0.
Link: https://lore.kernel.org/all/178454233992.290363.18323091580600697731.stgit@devnote2/
Fixes: ab105a4fb8 ("tracing: Use tracing error_log with probe events")
Cc: stable@vger.kernel.org
Assisted-by: Antigravity:gemini-3.5-flash
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
In trace_probe_match_command_args(), a stack buffer buf[MAX_ARGSTR_LEN + 1]
(256 bytes) is used to format "<name>=<comm>". However, since name can
be up to 32 bytes (MAX_ARG_NAME_LEN) and comm up to 255 bytes
(MAX_ARGSTR_LEN), the formatted string can exceed 256 bytes and get
truncated by snprintf(), causing spurious argument matching failures.
Instead of formatting into a temporary buffer on stack, compare the
argument name, the '=' delimiter, and the comm expression directly.
Link: https://lore.kernel.org/all/178454233010.290363.10428767141343428804.stgit@devnote2/
Fixes: eb5bf81330 ("tracing/kprobe: Add per-probe delete from event")
Cc: stable@vger.kernel.org
Assisted-by: Antigravity:gemini-3.5-flash
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
- Fix a UAF in socket clone early bailout paths (Matt Bobrowski)
- Reject unhashed UDP sockets on sockmap update to prevent refcount leaks
(Michal Luczaj)
- Account for receive queue data in FIONREAD on sockmap sockets without a
verdict program (Mattia Meleleo)
- Reject negative constant offsets for verifier buffer pointers (Sun Jian)
- Fix for tracing of kfuncs with implicit arguments (Ihor Solodrai)
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
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Merge tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Pull bpf fixes from Kumar Kartikeya Dwivedi:
- Fix a UAF in socket clone early bailout paths (Matt Bobrowski)
- Reject unhashed UDP sockets on sockmap update to prevent refcount
leaks (Michal Luczaj)
- Account for receive queue data in FIONREAD on sockmap sockets without
a verdict program (Mattia Meleleo)
- Reject negative constant offsets for verifier buffer pointers (Sun
Jian)
- Fix for tracing of kfuncs with implicit arguments (Ihor Solodrai)
* tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
selftests/bpf: Cover tracing implicit kfunc args
bpf: Fix tracing of kfuncs with implicit args
selftests/bpf: Cover negative buffer pointer offsets
bpf: Reject negative const offsets for buffer pointers
selftests/bpf: Test FIONREAD on a sockmap socket without a verdict program
bpf, sockmap: Account for receive queue in FIONREAD without a verdict program
selftests/bpf: Fail unbound UDP on sockmap update
selftests/bpf: Adapt sockmap update error handling
bpf, sockmap: Reject unhashed UDP sockets on sockmap update
selftests/bpf: Ensure UDP sockets are bound
bpf: Fix UAF in sock clone early bailouts
A kfunc marked with KF_IMPLICIT_ARGS flag takes implicit arguments
(such as bpf_prog_aux) that the verifier injects at load time.
resolve_btfids strips those from the kfunc's BTF-visible prototype and
keeps the real kernel ABI in a counterpart _impl prototype [1].
fentry/fexit/fmod_ret/fsession programs may attach to the BPF kernel
functions, including those with implicit args. However
bpf_check_attach_target() and bpf_check_attach_btf_id_multi() extract
the struct btf_func_model from the wrong BTF prototype of the
kfunc. The btf_func_model is later read to construct the trampoline,
which then causes the injected implicit argument to be clobbered and
the kfunc dereferencing garbage.
Add btf_attach_func_proto() to resolve the real ABI prototype of the
kfunc the way the call site does: by looking up the _impl prototype
for a KF_IMPLICIT_ARGS kfunc. Use it at both attach-target model
construction sites.
To enable this, make two supporting changes:
* pass bpf_verifier_log instead of bpf_verifier_env to
find_kfunc_impl_proto(), so it can be reused from the attach path
* add btf_kfunc_check_flag() to test a flag across all of a kfunc's
hook sets, because a program attaching to a kfunc is not in the
kfunc's call-set
KF_IMPLICIT_ARGS must be consistent across the sets, so
btf_kfunc_check_flag() returns -EINVAL on inconsistency.
btf_kfunc_check_flag() reads the kfunc's flags from the target's
kfunc_set_tab. For a module BTF that table is stable only after the
module is live, so take a module reference around the read, mirroring
how the kfunc call path gates the same lookup with btf_try_get_module().
The remaining call sites of btf_distill_func_proto() are safe as
is. The BPF_TRACE_ITER case distills a registered iterator's
prototype, and bpf_struct_ops_desc_init() distills the
function-pointer members of a struct_ops type. Neither is a kfunc, and
so can't have implicit arguments.
[1] https://lore.kernel.org/all/20260120222638.3976562-1-ihor.solodrai@linux.dev/
Fixes: 64e1360524 ("bpf: Verifier support for KF_IMPLICIT_ARGS")
Reported-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ihor Solodrai <ihor.solodrai@linux.dev>
Link: https://github.com/sched-ext/scx/issues/3687#issuecomment-4906694106
Link: https://patch.msgid.link/20260713235223.1639022-2-ihor.solodrai@linux.dev
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
LIVEUPDATE_SESSION_GET_NAME was developed in the liveupdate/next branch
while the session type validation change was carried in liveupdate-fixes.
When the conflict between the two branches was resolved, the GET_NAME
operation descriptor picked up the structure and last member from
RETRIEVE_FD.
This makes both its known size and minimum size 16 bytes rather than 72.
A zero-initialized request still succeeds because luo_session_get_name()
writes the full name before luo_ucmd_respond() copies the full GET_NAME
response to userspace. However, copy_struct_from_user() treats the
output-only name field as unknown trailing data and rejects the request
with -E2BIG if any byte in that field is nonzero.
Use the GET_NAME structure and its name field in the descriptor.
Link: https://lore.kernel.org/all/ahWlYXNjGUbkKoHy@sirena.org.uk/
Assisted-by: Codex:gpt-5.6-sol
Reviewed-by: Pratyush Yadav (Google) <pratyush@kernel.org>
Signed-off-by: Jackie Liu <liuyun01@kylinos.cn>
Link: https://patch.msgid.link/20260716012607.22020-1-liu.yun@linux.dev
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
The verifier rejects variable offsets for PTR_TO_TP_BUFFER and PTR_TO_BUF
accesses, but it currently accepts a constant negative offset produced by
pointer arithmetic.
Commit 022ac07508 ("bpf: use reg->var_off instead of reg->off for
pointers") moved constant pointer offsets from reg->off to reg->var_off.
However, __check_buffer_access() continued to check only the instruction
offset. An access with reg->var_off equal to -8 and an instruction offset
of zero therefore passes verification.
For writable raw tracepoints, the access end is also calculated from the
unsigned reg->var_off.value. An eight-byte access starting at -8 wraps
the calculated end to zero, allowing the program to load and attach
without increasing max_tp_access.
After ensuring that reg->var_off is constant, calculate the effective
access start using signed arithmetic and reject it when it is negative.
Use the validated start to calculate the access end for both
PTR_TO_TP_BUFFER and PTR_TO_BUF.
Fixes: 022ac07508 ("bpf: use reg->var_off instead of reg->off for pointers")
Signed-off-by: Sun Jian <sun.jian.kdev@gmail.com>
Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
Cc: stable@vger.kernel.org # 5.2.0
Link: https://patch.msgid.link/20260714093846.18159-2-sun.jian.kdev@gmail.com
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
- A cpuset that never set its memory nodes could divide by zero when a
task's mempolicy rebinds on CPU hotplug. Rebind against the effective
nodes, which are always populated.
- Documentation fixes for memory.stat, io.stat, and the misc and v1 RDMA
controllers.
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Merge tag 'cgroup-for-7.2-rc3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup fixes from Tejun Heo:
- A cpuset that never set its memory nodes could divide by zero when a
task's mempolicy rebinds on CPU hotplug. Rebind against the effective
nodes, which are always populated
- Documentation fixes for memory.stat, io.stat, and the misc and v1
RDMA controllers
* tag 'cgroup-for-7.2-rc3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
Docs/admin-guide/cgroup-v2: note blkcg_debug_stats gates io.latency stats
Docs/admin-guide/cgroup-v1: document rdma.peak, rdma.events and rdma.events.local
Docs/admin-guide/cgroup-v2: drop stale misc interface file count
cgroup/cpuset: rebind mm mempolicy to effective_mems, not mems_allowed
Docs/admin-guide/cgroup-v2: fix memory.stat doc details
- Lifecycle fixes for the new sub-scheduler support: two use-after-frees
and an enable-failure path that left a half-initialized sub-scheduler
linked.
- Two dispatch-path locking bugs: a spurious scheduler abort from a
migration race, and a lockdep splat from stale runqueue-lock tracking.
- Callback and task-state fixes: stale scheduler-owned state on a task
leaving SCX, a weight callback running after disable, and a bogus
warning on core-scheduling forced idle.
- On nohz_full, finite-slice tasks could miss the tick that expires their
slice. Enable it when such a task is picked, with a selftest.
- Smaller fixes: userspace CPU-mask helpers, ratelimited deprecation
warnings, docs and a sparse annotation.
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Merge tag 'sched_ext-for-7.2-rc3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext
Pull sched_ext fixes from Tejun Heo:
- Lifecycle fixes for the new sub-scheduler support: two
use-after-frees and an enable-failure path that left a
half-initialized sub-scheduler linked.
- Two dispatch-path locking bugs: a spurious scheduler abort from a
migration race, and a lockdep splat from stale runqueue-lock
tracking.
- Callback and task-state fixes: stale scheduler-owned state on a task
leaving SCX, a weight callback running after disable, and a bogus
warning on core-scheduling forced idle.
- On nohz_full, finite-slice tasks could miss the tick that expires
their slice. Enable it when such a task is picked, with a selftest.
- Smaller fixes: userspace CPU-mask helpers, ratelimited deprecation
warnings, docs and a sparse annotation.
* tag 'sched_ext-for-7.2-rc3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext:
sched_ext: Skip ops.set_weight() for disabled tasks
tools/sched_ext: scx - Fix cmask_subset(), cmask_equal() and cmask_weight()
sched_ext: Fix premature ops->priv publication in scx_alloc_and_add_sched()
sched_ext: Record an error on errno-only sub-enable failure
selftests/sched_ext: Verify nohz_full tick behavior
sched_ext: Enable tick for finite slices on nohz_full
sched_ext: Preserve rq tracking across local DSQ dispatch
sched_ext: Documentation: Fix ops table header reference
sched_ext: Don't warn on core-sched forced idle in put_prev_task_scx()
sched_ext: Pin parent scx_sched across a child sub-scheduler's lifetime
sched_ext: Annotate ksyncs with __rcu in alloc/free_kick_syncs()
sched_ext: Check remote rq eligibility under task's rq lock
sched_ext: Reset dsq_vtime and slice when a task leaves SCX
sched_ext: Avoid flooding the log with deprecation warnings
- Free field in error path of synthetic event parse
In __create_synth_event() the field was allocated but was not freed in the
error path.
- Fix ring_buffer_event_length() on 8 byte aligned architectures
On architectures with CONFIG_HAVE_64BIT_ALIGNED_ACCESS set to y,
the ring_buffer_event_length() may return the wrong size. This
is because archs with that config set will always use the "big
event meta header" as that is 8 bytes keeping the payload 8 bytes
aligned, even when a 4 byte header could hold the size of the
event.
But ring_buffer_event_length() doesn't take this into account and only
subtracts 4 bytes for the meta header in the length when it should have
subtracted 8 bytes.
- Have osnoise wait for a full rcu synchronization on unregister
osnoise_unregister_instance() used to call synchronize_rcu() before
freeing its copy of the instance but was switched to kfree_rcu().
The osniose tracer has code that traverses the instances that it
uses, and inst is just a pointer to that instance. By using kfree_rcu()
instead of synchronize_rcu(), the instance that the inst pointer is
pointing to can be freed while the osnoise code is still referencing it.
That is, a rmdir on an instance first unregisters the tracer. When the
unregister finishes, the rmdir expects that the tracer is finished with
the instance that it is using. By putting back the synchronize_rcu()
in osnoise_unregister_instance() the unregistering of osnoise will now
return when all the users of the instance have finished.
- Remove an unused setting of "ret" in tracing_set_tracer()
- Fix ring_buffer_read_page() copying events
The commit that changed ring_buffer_read_page() to show dropped events
from the buffer itself, split the "commit" variable between the commit
value (with flags) and "size" that holds the size of the sub-buffer.
A cut and paste error changed the test of the reading from checking the
size of the buffer to the size of the event causing reads to only read one
event at a time.
- Make tracepoint_printk a static variable
When the tracing sysctl knobs were move from sysctl.c to trace.c, the
variable tracepoint_printk no longer needed to be global. Make it static.
- Fix some typos
- Fix NULL pointer dereference in func_set_flag()
The flags update of the function tracer first checks if the value of the
flag is the same and exits if they are, and then it checks if the current
tracer is the function tracer and exits if it isn't. The problem is that
these checks need to be in a reversed order, as if the tracer isn't the
function tracer, then the flag being checked may not exist. Reverse the
order of these checks.
- Fix ufs core trace events to not dereference a pointer in TP_printk()
The TP_printk() part of the TRACE_EVENT() macro is called when the user
reads the "trace" file. This can be seconds, minutes, hours, days, weeks,
and even months after the data was recorded into the ring buffer. Thus,
saving a pointer to an object into the ring buffer and then dereferencing
it from TP_printk() can cause harm as the object the pointer is pointing
to may no longer exist.
Fix all the trace events in ufs core to save the device name in the ring
buffer instead of dereferencing the device descriptor from TP_printk().
- Prevent out-of-bound reads in glob matching of trace events
The filter logic of events allows simple glob logic to add wild cards to
filter on strings. But some events have fields that may not have a
terminating 'nul' character. This may cause the glob matching to go beyond
the string. Change the logic to always pass in the length of the field
that is being matched.
- Add no-rcu-check version of trace_##event##_enabled()
The trace_##event##_enabled() usually wraps trace events to do extra work
that is only needed when the trace event is enabled. But this can hide
events that are placed in locations where RCU is not watching, and can
make lockdep not see these bugs when the event is not enabled.
The trace_##event##_enabled() was updated to always test to make sure RCU
is watching to catch locations that may call events without RCU being
active.
This caused a false positive for the irq_disabled() and related events. As
that use trace_irq_disabled_enabled() to force RCU to be watching when the
event is enabled via the ct_irq_enter() function, calls the event, and
then calls ct_irq_exit() to put RCU back to its original state.
The trace_irq_disabled_enabled() should not trigger a warning when RCU is
not watching because the code within its block handles the case properly.
Make a __trace_##event##_enabled() version for this event to use that
doesn't check RCU is watching as it handles the case when it isn't.
- Fix use-after-free in user_event_mm_dup()
When the enabler is removed from the link list, it is freed immediately.
But it is protected via RCU and needs to be freed after an RCU
grace period. Use queue_rcu_work() so that the event_mutex can also
be taken as user_event_put() takes the mutex on the last reference
is released.
- Free type string in error path of parse_synth_field()
There's an error path in parse_synth_field() where the allocated type
string is not freed.
- Add selftest that tests deferred event teardown
- Fix leak in error path of trace_remote_alloc_buffer()
If page allocation fails, the desc->nr_cpus is not incremented for the
current CPU and the allocations done for it are not freed.
- Fix allocation length in trace_remote_alloc_buffer()
The logic to calculate the struct_len was doing a double count and setting
the value too large. Calculate the size upfront to fix the error and
simplify the logic.
- Fix sparse CPU masks in ring_buffer_desc()
If there are sparse CPUs (gaps in the numbering), the ring_buffer_desc()
will fail as it tests the CPU number against the number of CPUs that are
used.
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Merge tag 'trace-v7.2-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing fixes from Steven Rostedt:
- Free field in error path of synthetic event parse
In __create_synth_event() the field was allocated but was not freed
in the error path
- Fix ring_buffer_event_length() on 8 byte aligned architectures
On architectures with CONFIG_HAVE_64BIT_ALIGNED_ACCESS set to y, the
ring_buffer_event_length() may return the wrong size. This is because
archs with that config set will always use the "big event meta
header" as that is 8 bytes keeping the payload 8 bytes aligned, even
when a 4 byte header could hold the size of the event
But ring_buffer_event_length() doesn't take this into account and
only subtracts 4 bytes for the meta header in the length when it
should have subtracted 8 bytes
- Have osnoise wait for a full rcu synchronization on unregister
osnoise_unregister_instance() used to call synchronize_rcu() before
freeing its copy of the instance but was switched to kfree_rcu(). The
osniose tracer has code that traverses the instances that it uses,
and inst is just a pointer to that instance. By using kfree_rcu()
instead of synchronize_rcu(), the instance that the inst pointer is
pointing to can be freed while the osnoise code is still referencing
it
That is, a rmdir on an instance first unregisters the tracer. When
the unregister finishes, the rmdir expects that the tracer is
finished with the instance that it is using. By putting back the
synchronize_rcu() in osnoise_unregister_instance() the unregistering
of osnoise will now return when all the users of the instance have
finished
- Remove an unused setting of "ret" in tracing_set_tracer()
- Fix ring_buffer_read_page() copying events
The commit that changed ring_buffer_read_page() to show dropped
events from the buffer itself, split the "commit" variable between
the commit value (with flags) and "size" that holds the size of the
sub-buffer. A cut and paste error changed the test of the reading
from checking the size of the buffer to the size of the event causing
reads to only read one event at a time
- Make tracepoint_printk a static variable
When the tracing sysctl knobs were move from sysctl.c to trace.c, the
variable tracepoint_printk no longer needed to be global. Make it
static
- Fix some typos
- Fix NULL pointer dereference in func_set_flag()
The flags update of the function tracer first checks if the value of
the flag is the same and exits if they are, and then it checks if the
current tracer is the function tracer and exits if it isn't. The
problem is that these checks need to be in a reversed order, as if
the tracer isn't the function tracer, then the flag being checked may
not exist. Reverse the order of these checks
- Fix ufs core trace events to not dereference a pointer in TP_printk()
The TP_printk() part of the TRACE_EVENT() macro is called when the
user reads the "trace" file. This can be seconds, minutes, hours,
days, weeks, and even months after the data was recorded into the
ring buffer. Thus, saving a pointer to an object into the ring buffer
and then dereferencing it from TP_printk() can cause harm as the
object the pointer is pointing to may no longer exist
Fix all the trace events in ufs core to save the device name in the
ring buffer instead of dereferencing the device descriptor from
TP_printk()
- Prevent out-of-bound reads in glob matching of trace events
The filter logic of events allows simple glob logic to add wild cards
to filter on strings. But some events have fields that may not have a
terminating 'nul' character. This may cause the glob matching to go
beyond the string. Change the logic to always pass in the length of
the field that is being matched
- Add no-rcu-check version of trace_##event##_enabled()
The trace_##event##_enabled() usually wraps trace events to do extra
work that is only needed when the trace event is enabled. But this
can hide events that are placed in locations where RCU is not
watching, and can make lockdep not see these bugs when the event is
not enabled
The trace_##event##_enabled() was updated to always test to make sure
RCU is watching to catch locations that may call events without RCU
being active
This caused a false positive for the irq_disabled() and related
events. As that use trace_irq_disabled_enabled() to force RCU to be
watching when the event is enabled via the ct_irq_enter() function,
calls the event, and then calls ct_irq_exit() to put RCU back to its
original state
The trace_irq_disabled_enabled() should not trigger a warning when
RCU is not watching because the code within its block handles the
case properly. Make a __trace_##event##_enabled() version for this
event to use that doesn't check RCU is watching as it handles the
case when it isn't
- Fix use-after-free in user_event_mm_dup()
When the enabler is removed from the link list, it is freed
immediately. But it is protected via RCU and needs to be freed after
an RCU grace period. Use queue_rcu_work() so that the event_mutex can
also be taken as user_event_put() takes the mutex on the last
reference is released
- Free type string in error path of parse_synth_field()
There's an error path in parse_synth_field() where the allocated type
string is not freed
- Add selftest that tests deferred event teardown
- Fix leak in error path of trace_remote_alloc_buffer()
If page allocation fails, the desc->nr_cpus is not incremented for
the current CPU and the allocations done for it are not freed
- Fix allocation length in trace_remote_alloc_buffer()
The logic to calculate the struct_len was doing a double count and
setting the value too large. Calculate the size upfront to fix the
error and simplify the logic
- Fix sparse CPU masks in ring_buffer_desc()
If there are sparse CPUs (gaps in the numbering), the
ring_buffer_desc() will fail as it tests the CPU number against the
number of CPUs that are used
* tag 'trace-v7.2-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
ring-buffer: Allow sparse CPU masks in ring_buffer_desc()
tracing/remotes: Fix struct_len in trace_remote_alloc_buffer()
tracing/remotes: Fix leak in trace_remote_alloc_buffer() error path
selftests/user_events: Wait for deferred event teardown after unregister
tracing/synthetic: Free type string on error path
tracing/user_events: Fix use-after-free in user_event_mm_dup()
tracing: Add a no-rcu-check version of trace_##event##_enabled()
tracing: Prevent out-of-bounds read in glob matching
ufs: core: tracing: Do not dereference pointers in TP_printk()
tracing: Fix NULL pointer dereference in func_set_flag()
samples: ftrace: Fix typos in benchmark comment
tracing: Make tracepoint_printk static as not exported
ring-buffer: Fix ring_buffer_read_page() copying only one event per page
tracing: Remove unused ret assignment in tracing_set_tracer()
tracing/osnoise: Call synchronize_rcu() when unregistering
ring-buffer: Fix event length with forced 8-byte alignment
tracing/synthetic: Free pending field on error path
unearthed other races in the area (Thomas Gleixner)
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'timers-urgent-2026-07-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fix from Ingo Molnar:
- Fix a subtle posix-cpu-timers vs. exec() race, which
unearthed other races in the area (Thomas Gleixner)
* tag 'timers-urgent-2026-07-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
posix-cpu-timers: Prevent UAF caused by non-leader exec() race
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Merge tag 'audit-pr-20260710' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit
Pull audit fixes from Paul Moore:
"Two relatively small audit patches to fix potential data races with
the main audit backlog queue as well as possible integer overflows
when logging data as hex strings"
* tag 'audit-pr-20260710' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit:
audit: fix potential integer overflow in audit_log_n_hex()
audit: Fix data races of skb_queue_len() readers on audit_queue
No user currently relies on sparse CPU masks, but the descriptor logic already
supports them via linear fallback. Remove the arbitrary limitation.
Link: https://patch.msgid.link/20260709160017.1729517-4-vdonnefort@google.com
Fixes: 2e67fabd8b ("ring-buffer: Introduce ring-buffer remotes")
Reported-by: Sashiko <sashiko-bot@kernel.org>
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Pre-calculate desc->struct_len up-front in trace_remote_alloc_buffer()
with trace_buffer_desc_size() to fix double-counting.
While at it, use the accessor __first_ring_buffer_desc().
Link: https://patch.msgid.link/20260709160017.1729517-3-vdonnefort@google.com
Fixes: 96e43537af ("tracing: Introduce trace remotes")
Reported-by: Sashiko <sashiko-bot@kernel.org>
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
If page allocation fails in trace_remote_alloc_buffer(), desc->nr_cpus
is not yet incremented for the current CPU. As a consequence, on error,
half-allocated rb_desc will not be freed in trace_remote_free_buffer().
Increment desc->nr_cpus as soon as the first allocation for the current
CPU has succeeded.
Link: https://patch.msgid.link/20260709160017.1729517-2-vdonnefort@google.com
Fixes: 96e43537af ("tracing: Introduce trace remotes")
Reported-by: Sashiko <sashiko-bot@kernel.org>
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
When switching a task's sched_class away from sched_ext, we get the
following sequence of events in __sched_setscheduler():
sched_change_begin()
switched_from_scx()
scx_disable_task(p)
ops.disable(p)
__setscheduler_params()
set_load_weight()
reweight_task_scx(p)
ops.set_weight(p)
p->sched_class = next_class;
sched_change_end()
...
Notably, ops.set_weight() is called _after_ ops.disable().
This violates the expected semantics of the callbacks, the expectation
being that ops.disable() can only be followed by ops.exit_task() or
ops.enable().
Skipping the weight adjustment for disabled tasks should be harmless
since the weight will be recalculated in scx_enable_task() if the task
ever rejoins SCX.
Fixes: 637b068282 ("sched: Fold sched_class::switch{ing,ed}_{to,from}() into the change pattern")
Cc: stable@vger.kernel.org # v6.19+
Signed-off-by: Kuba Piecuch <jpiecuch@google.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
map_range() reads rb->aux_pages[], rb->aux_nr_pages and rb->aux_pgoff via
perf_mmap_to_page() while holding only event->mmap_mutex. Those fields are
serialized by rb->aux_mutex, and mmap_mutex is per event.
Thus, two events sharing one rb via PERF_EVENT_IOC_SET_OUTPUT can race
rb_alloc_aux() with map_range(), leading to a page-UAF scenario as follows:
CPU 0 CPU 1
===== =====
rb_alloc_aux() map_range()
[1]: allocate rb->aux_pages[0]
[2]: rb->aux_nr_pages++
[3]: perf_mmap_to_page()
returns rb->aux_pages[0]
[4]: map it as VM_PFNMAP
[5]: rb->aux_pgoff = 1
munmap the page
[6]: free rb->aux_pages[0]
Pages mapped as VM_PFNMAP have no refcount protection, so CPU 1 holds a
mapping to a freed physical frame.
Fix this by taking rb->aux_mutex across the page walk in map_range().
Fixes: b709eb872e ("perf: map pages in advance")
Signed-off-by: Lee Jia Jie <jiajie.lee@starlabs.sg>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: stable@vger.kernel.org
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
