linux/kernel
Deepanshu Kartikey 372f853424 tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
Writing to buffer_subbuf_size_kb calls ring_buffer_subbuf_order_set(),
which frees every sub-buffer of the ring buffer, including the reader
page, and replaces them with newly allocated ones.

Readers of trace_pipe hold pointers into those pages. ring_buffer_peek()
looks up an event under cpu_buffer->reader_lock but returns the event
pointer after dropping the lock, and peek_next_entry() then calls
ring_buffer_event_length() and ring_buffer_event_data() on it. If the
sub-buffer order is changed in that window, the reader dereferences
freed memory:

  BUG: KASAN: use-after-free in ring_buffer_peek+0x3e0/0x430
  Read of size 1 at addr ffff88802a4cf010 by task syz-executor989/6002

  Freed by:
   free_buffer_page kernel/trace/ring_buffer.c:398 [inline]
   ring_buffer_subbuf_order_set+0x1325/0x18e0 kernel/trace/ring_buffer.c:7444
   buffer_subbuf_size_write+0x182/0x280 kernel/trace/trace.c:8221

Take trace_access_lock(RING_BUFFER_ALL_CPUS) around the order change.
This is the lock trace_pipe readers already hold across their entire
peek-and-print loop, so the swap can no longer race with a reader that
is dereferencing a peeked event.

Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260817140655.5694-1-kartikey406@gmail.com
Fixes: f9b94daa54 ("ring-buffer: Set new size of the ring buffer sub page")
Reported-by: syzbot+685955db58555575fdd2@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=685955db58555575fdd2
Tested-by: syzbot+685955db58555575fdd2@syzkaller.appspotmail.com
Reviewed-by: Bradley Morgan <include@grrlz.net>
Signed-off-by: Deepanshu Kartikey <kartikey406@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-08-22 17:43:42 -04:00
..
bpf tracing updates for v7.3: 2026-08-19 14:06:14 -07:00
cgroup Merge branch 'sched/urgent' 2026-08-14 16:12:58 +02:00
configs slab: support for compiler-assisted type-based slab cache partitioning 2026-05-14 10:44:09 +02:00
debug kgdb: update outdated references to kgdb_wait() 2026-04-21 16:41:54 +01:00
dma dma-mapping updates for Linux 7.2: 2026-06-17 12:20:21 -07:00
entry entry: Rework trace_syscall_enter() 2026-07-20 20:38:40 +02:00
events Performance events updates for v7.3: 2026-08-18 12:31:07 -07:00
futex Futex updates: 2026-08-18 15:26:35 -07:00
gcov Convert more 'alloc_obj' cases to default GFP_KERNEL arguments 2026-02-21 20:03:00 -08:00
irq Generic interrupt subsystem updates: 2026-08-18 15:19:50 -07:00
kcsan kcsan: test: Adjust "expect" allocation type for kmalloc_obj 2026-02-26 09:54:08 -08:00
livepatch Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
liveupdate Merge branch 'misc' into next 2026-08-04 10:51:49 +03:00
locking irq,spin_lock: Add counted interrupt disabling/enabling 2026-08-10 10:50:18 +02:00
module module: decompress: check return value of module_extend_max_pages() 2026-06-04 16:37:32 +00:00
power PM: sleep: Allow disabling DPM watchdog by default 2026-07-23 15:46:34 +02:00
printk printk: fix typos in comments 2026-06-02 15:36:06 +02:00
rcu Updates for the NOHZ subsystem: 2026-06-15 13:48:52 +05:30
sched Timers and timekeeping core updates: 2026-08-18 16:23:56 -07:00
time VDSO updates: 2026-08-18 16:56:25 -07:00
trace tracing: Fix use-after-free in trace_pipe read on sub-buffer order change 2026-08-22 17:43:42 -04:00
unwind Convert more 'alloc_obj' cases to default GFP_KERNEL arguments 2026-02-21 20:03:00 -08:00
.gitignore kheaders: rebuild kheaders_data.tar.xz when a file is modified within a minute 2025-06-24 20:30:37 +09:00
acct.c fs: move SB_I_USERNS_VISIBLE to FS_USERNS_MOUNT_RESTRICTED 2026-05-11 23:13:01 +02:00
async.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
audit_fsnotify.c audit: fix recursive locking deadlock in audit_dupe_exe() 2026-05-27 19:15:34 -04:00
audit_tree.c audit: use 'unsigned int' instead of 'unsigned' 2026-05-26 17:15:30 -04:00
audit_watch.c audit: fix recursive locking deadlock in audit_dupe_exe() 2026-05-27 19:15:34 -04:00
audit.c audit: fix potential integer overflow in audit_log_n_string() 2026-07-29 16:19:06 -04:00
audit.h audit: fix recursive locking deadlock in audit_dupe_exe() 2026-05-27 19:15:34 -04:00
auditfilter.c audit: fix potential use-after-free in audit_del_rule() 2026-07-29 16:19:06 -04:00
auditsc.c audit/stable-7.2 PR 20260615 2026-06-17 12:55:09 +01:00
backtracetest.c
bounds.c x86/asm: Remove ANNOTATE_DATA_SPECIAL usage 2025-12-03 16:53:19 +01:00
capability.c capability: Remove unused has_capability 2025-03-07 22:03:09 -06:00
cfi.c cfi: Move BPF CFI types and helpers to generic code 2025-07-31 18:23:53 -07:00
compat.c
configs.c
context_tracking.c context_tracking: Remove rcu_task_trace_heavyweight_{enter,exit}() 2026-01-01 16:39:46 +08:00
cpu_pm.c syscore: Pass context data to callbacks 2025-11-14 10:01:52 +01:00
cpu.c Misc CPU hotplug fixes: 2026-06-23 16:43:24 -07:00
crash_core_test.c crash: add KUnit tests for crash_exclude_mem_range 2025-09-13 17:32:55 -07:00
crash_core.c powerpc/kexec_file: Use crash_exclude_core_ranges() helper 2026-06-30 18:49:06 +03:00
crash_dump_dm_crypt.c crash_dump: release keyring reference at the correct time 2026-07-13 10:04:47 +03:00
crash_reserve.c kernel/crash: remove inclusion of crypto/sha1.h 2026-03-27 21:19:46 -07:00
cred.c exec_state: relocate dumpable information 2026-05-26 11:02:01 +02:00
delayacct.c delayacct: fix uapi timespec64 definition 2026-02-08 00:13:32 -08:00
dma.c
elfcorehdr.c
exec_domain.c
exec_state.c exec_state: relocate dumpable information 2026-05-26 11:02:01 +02:00
exit.c ipc-7.3-rc1.misc 2026-08-17 08:27:30 -07:00
exit.h
extable.c
fail_function.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
fork.c SMP core updates: 2026-08-18 15:29:53 -07:00
freezer.c freezer: Clarify that only cgroup1 freezer uses PM freezer 2025-10-30 20:10:27 +01:00
gen_kheaders.sh kheaders: make it possible to override TAR 2025-08-06 10:23:36 +09:00
groups.c treewide: Replace kmalloc with kmalloc_obj for non-scalar types 2026-02-21 01:02:28 -08:00
hung_task.c hung_task: explicitly report I/O wait state in log output 2026-03-27 21:19:40 -07:00
iomem.c mm/memremap: Pass down MEMREMAP_* flags to arch_memremap_wb() 2025-02-21 15:05:38 +01:00
irq_work.c irq_work: Fix use-after-free in irq_work_single() on PREEMPT_RT 2026-05-11 16:28:04 +02:00
jump_label.c jump_label: use ATOMIC_INIT() for initialization of .enabled 2026-03-16 13:16:48 +01:00
kallsyms_internal.h kallsyms: Get rid of kallsyms relative base 2026-01-22 15:58:22 -07:00
kallsyms_selftest.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
kallsyms_selftest.h
kallsyms.c mm.git review status for linus..mm-nonmm-stable 2026-02-12 12:13:01 -08:00
kcmp.c fs: add real_fs to track task's actual fs_struct 2026-06-29 10:43:45 +02:00
Kconfig.freezer
Kconfig.hz kernel: Fix "select" wording on HZ_250 description 2025-02-21 09:20:30 +01:00
Kconfig.kexec liveupdate: kho: move to kernel/liveupdate 2025-11-27 14:24:33 -08:00
Kconfig.locks locking/qspinlock: Add contended_release tracepoint 2026-08-07 17:58:10 +02:00
Kconfig.preempt preempt: Introduce HAS_SEPARATE_PREEMPT_RESCHED_BITS 2026-08-10 10:50:19 +02:00
kcov.c kcov: use WRITE_ONCE() for selftest mode stores 2026-06-04 14:49:26 -07:00
kexec_core.c liveupdate: skip serialization for context-preserving kexec 2026-06-01 09:19:38 +03:00
kexec_elf.c kexec: initialize ELF lowest address to ULONG_MAX 2025-03-16 22:30:47 -07:00
kexec_file.c kexec_file: skip checksum verification when safe 2026-07-01 13:01:08 +03:00
kexec_internal.h kexec: enable CMA based contiguous allocation 2025-08-02 12:01:38 -07:00
kexec.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
kheaders.c
kprobes.c kprobes: Remove unneeded warnings from __arm_kprobe_ftrace() 2026-03-13 23:15:26 +09:00
kstack_erase.c sysctl: remove __user qualifier from stack_erasing_sysctl buffer argument 2025-11-27 15:44:53 +01:00
ksyms_common.c
ksysfs.c kernel: ksysfs: initialize kernel_kobj earlier 2026-04-03 19:39:52 +02:00
kthread.c exec_state: relocate dumpable information 2026-05-26 11:02:01 +02:00
latencytop.c treewide: const qualify ctl_tables where applicable 2025-01-28 13:48:37 +01:00
Makefile exec: introduce struct task_exec_state 2026-05-26 11:02:01 +02:00
module_signature.c module: Give 'enum pkey_id_type' a more specific name 2026-03-24 21:42:37 +00:00
notifier.c
nscommon.c nsfs: tighten permission checks for ns iteration ioctls 2026-02-27 22:00:08 +01:00
nsproxy.c vfs-7.1-rc1.mount.v2 2026-04-14 19:59:25 -07:00
nstree.c nstree: tighten permission checks for listing 2026-02-27 22:00:11 +01:00
padata.c padata: Put CPU offline callback in ONLINE section to allow failure 2026-03-22 11:17:59 +09:00
panic.c bug/kunit: Core support for suppressing warning backtraces 2026-05-14 10:50:00 -06:00
params.c kernel: param: initialize module_kset in a pure_initcall 2026-06-08 23:27:56 +02:00
pid_namespace.c pid_namespace: allow opening pid_for_children before init was created 2026-03-20 14:44:26 +01:00
pid_sysctl.h treewide: const qualify ctl_tables where applicable 2025-01-28 13:48:37 +01:00
pid.c pid: reject allocations through dead ancestor pid namespaces 2026-08-12 12:56:30 +02:00
profile.c
ptrace.c exec_state: relocate dumpable information 2026-05-26 11:02:01 +02:00
range.c
reboot.c treewide: Replace kmalloc with kmalloc_obj for non-scalar types 2026-02-21 01:02:28 -08:00
regset.c
relay.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
resource_kunit.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
resource.c resource: Make resource_alignment() input const resource 2026-06-23 12:08:51 -05:00
rseq.c rseq: Reenable performance optimizations conditionally 2026-05-06 17:40:27 +02:00
scftorture.c scftorture: Remove preempt_disable() in scftorture_invoke_one() 2026-07-16 09:24:56 +02:00
scs.c scs: fix a wrong parameter in __scs_magic 2025-11-12 10:00:13 -08:00
seccomp.c seccomp, treewide: Rename and convert __secure_computing() to return boolean 2026-07-12 12:38:02 +02:00
signal.c posix-cpu-timers: Prevent UAF caused by non-leader exec() race 2026-07-05 11:44:06 +02:00
smp.c SMP core updates: 2026-08-18 15:29:53 -07:00
smpboot.c sched/smp: Use the SMP version of idle_thread_set_boot_cpu() 2025-06-13 08:47:20 +02:00
smpboot.h
softirq.c preempt: Introduce HAS_SEPARATE_PREEMPT_RESCHED_BITS 2026-08-10 10:50:19 +02:00
stacktrace.c
static_call_inline.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
static_call.c
stop_machine.c stop_machine: Make stop_one_cpu_nowait() return void 2026-07-31 12:35:26 +02:00
sys_ni.c time: Respect COMPAT_32BIT_TIME for old time type functions 2026-07-07 23:52:53 +02:00
sys.c exec_state: relocate dumpable information 2026-05-26 11:02:01 +02:00
sysctl-test.c sysctl: move u8 register test to lib/test_sysctl.c 2025-04-14 14:13:41 +02:00
sysctl.c sysctl: fix uninitialized variable in proc_do_large_bitmap 2026-03-26 09:32:19 +01:00
task_work.c task_work: Fix NMI race condition 2025-10-29 10:29:54 +01:00
taskstats.c taskstats: retain dead thread stats in TGID queries 2026-05-28 21:24:41 -07:00
torture.c torture: Add torture_sched_set_normal() for user-specified nice values 2026-05-24 09:38:47 +02:00
tracepoint.c tracepoint: balance regfunc() on func_add() failure in tracepoint_add_func() 2026-04-14 05:17:02 -04:00
tsacct.c tsacct: skip all kernel threads 2026-01-26 19:07:13 -08:00
ucount.c binfmt_misc: correctly account pre-opened interpreters 2026-08-03 23:36:18 +02:00
uid16.c
uid16.h
umh.c fs: add umh argument to struct kernel_clone_args 2026-06-29 10:54:41 +02:00
up.c smp: Refactor remote CPU selection in smp_call_function_any() 2026-07-16 09:24:55 +02:00
user_namespace.c Convert remaining multi-line kmalloc_obj/flex GFP_KERNEL uses 2026-02-22 08:26:33 -08:00
user-return-notifier.c
user.c binfmt_misc: use RCU for the handler lookup 2026-08-03 10:08:36 +02:00
utsname_sysctl.c treewide: const qualify ctl_tables where applicable 2025-01-28 13:48:37 +01:00
utsname.c namespace-6.18-rc1 2025-09-29 11:20:29 -07:00
vhost_task.c vhost_task_create: kill unnecessary .exit_signal initialization 2026-06-10 02:17:00 -04:00
vmcore_info.c mm.git review status for linus..mm-nonmm-stable 2026-04-16 20:11:56 -07:00
watch_queue.c Convert 'alloc_flex' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
watchdog_buddy.c watchdog/hardlockup: improve buddy system detection timeliness 2026-03-27 21:19:47 -07:00
watchdog_perf.c watchdog/hardlockup: simplify perf event probe and remove per-cpu dependency 2026-02-08 00:13:35 -08:00
watchdog.c watchdog/hardlockup: improve buddy system detection timeliness 2026-03-27 21:19:47 -07:00
workqueue_internal.h workqueue: Show in-flight work item duration in stall diagnostics 2026-03-05 07:27:48 -10:00
workqueue.c workqueue: Changes for v7.2 2026-06-17 11:57:44 +01:00