linux/kernel
Li Huafei 7d606ae1ab kprobes: Skip clearing aggrprobe's post_handler in kprobe-on-ftrace case
[ Upstream commit 5dd7caf0bd ]

In __unregister_kprobe_top(), if the currently unregistered probe has
post_handler but other child probes of the aggrprobe do not have
post_handler, the post_handler of the aggrprobe is cleared. If this is
a ftrace-based probe, there is a problem. In later calls to
disarm_kprobe(), we will use kprobe_ftrace_ops because post_handler is
NULL. But we're armed with kprobe_ipmodify_ops. This triggers a WARN in
__disarm_kprobe_ftrace() and may even cause use-after-free:

  Failed to disarm kprobe-ftrace at kernel_clone+0x0/0x3c0 (error -2)
  WARNING: CPU: 5 PID: 137 at kernel/kprobes.c:1135 __disarm_kprobe_ftrace.isra.21+0xcf/0xe0
  Modules linked in: testKprobe_007(-)
  CPU: 5 PID: 137 Comm: rmmod Not tainted 6.1.0-rc4-dirty #18
  [...]
  Call Trace:
   <TASK>
   __disable_kprobe+0xcd/0xe0
   __unregister_kprobe_top+0x12/0x150
   ? mutex_lock+0xe/0x30
   unregister_kprobes.part.23+0x31/0xa0
   unregister_kprobe+0x32/0x40
   __x64_sys_delete_module+0x15e/0x260
   ? do_user_addr_fault+0x2cd/0x6b0
   do_syscall_64+0x3a/0x90
   entry_SYSCALL_64_after_hwframe+0x63/0xcd
   [...]

For the kprobe-on-ftrace case, we keep the post_handler setting to
identify this aggrprobe armed with kprobe_ipmodify_ops. This way we
can disarm it correctly.

Link: https://lore.kernel.org/all/20221112070000.35299-1-lihuafei1@huawei.com/

Fixes: 0bc11ed5ab ("kprobes: Allow kprobes coexist with livepatch")
Reported-by: Zhao Gongyi <zhaogongyi@huawei.com>
Suggested-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Li Huafei <lihuafei1@huawei.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-11-25 17:45:55 +01:00
..
bpf bpf: Initialize same number of free nodes for each pcpu_freelist 2022-11-25 17:45:45 +01:00
cgroup
configs
debug
dma
entry
events
gcov
irq
kcsan
livepatch
locking
power
printk
rcu
sched
time
trace ring-buffer: Include dropped pages in counting dirty patches 2022-11-25 17:45:54 +01:00
.gitignore
acct.c
async.c
audit_fsnotify.c
audit_tree.c
audit_watch.c
audit.c
audit.h
auditfilter.c
auditsc.c
backtracetest.c
bounds.c
capability.c
compat.c
configs.c
context_tracking.c
cpu_pm.c
cpu.c
crash_core.c
crash_dump.c
cred.c
delayacct.c
dma.c
exec_domain.c
exit.c
extable.c
fail_function.c
fork.c
freezer.c
futex.c
gen_kheaders.sh
groups.c
hung_task.c
iomem.c
irq_work.c
jump_label.c
kallsyms.c
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kcov.c
kexec_core.c
kexec_elf.c
kexec_file.c
kexec_internal.h
kexec.c
kheaders.c
kmod.c
kprobes.c kprobes: Skip clearing aggrprobe's post_handler in kprobe-on-ftrace case 2022-11-25 17:45:55 +01:00
ksysfs.c
kthread.c
latencytop.c
Makefile
module_signature.c
module_signing.c
module-internal.h
module.c
notifier.c
nsproxy.c
padata.c
panic.c
params.c
pid_namespace.c
pid.c
profile.c
ptrace.c
range.c
reboot.c
regset.c
relay.c
resource.c
rseq.c
scftorture.c
scs.c
seccomp.c
signal.c
smp.c
smpboot.c
smpboot.h
softirq.c
stackleak.c
stacktrace.c
static_call.c
stop_machine.c
sys_ni.c
sys.c
sysctl-test.c
sysctl.c
task_work.c
taskstats.c
test_kprobes.c
torture.c
tracepoint.c
tsacct.c
ucount.c
uid16.c
uid16.h
umh.c
up.c
user_namespace.c
user-return-notifier.c
user.c
usermode_driver.c
utsname_sysctl.c
utsname.c
watch_queue.c
watchdog_hld.c
watchdog.c
workqueue_internal.h
workqueue.c