diff options
| author | Masami Hiramatsu (Google) <mhiramat@kernel.org> | 2026-03-13 23:14:14 +0900 |
|---|---|---|
| committer | Masami Hiramatsu (Google) <mhiramat@kernel.org> | 2026-03-13 23:14:14 +0900 |
| commit | e113f0b46d19626ec15388bcb91432c9a4fd6261 (patch) | |
| tree | 15058f0c74f356e92d2e730ba43aa5c5145da409 /kernel | |
| parent | 1f318b96cc84d7c2ab792fcc0bfd42a7ca890681 (diff) | |
kprobes: avoid crash when rmmod/insmod after ftrace killed
After we hit ftrace is killed by some errors, the kernel crash if
we remove modules in which kprobe probes.
BUG: unable to handle page fault for address: fffffbfff805000d
PGD 817fcc067 P4D 817fcc067 PUD 817fc8067 PMD 101555067 PTE 0
Oops: Oops: 0000 [#1] SMP KASAN PTI
CPU: 4 UID: 0 PID: 2012 Comm: rmmod Tainted: G W OE
Tainted: [W]=WARN, [O]=OOT_MODULE, [E]=UNSIGNED_MODULE
RIP: 0010:kprobes_module_callback+0x89/0x790
RSP: 0018:ffff88812e157d30 EFLAGS: 00010a02
RAX: 1ffffffff805000d RBX: dffffc0000000000 RCX: ffffffff86a8de90
RDX: ffffed1025c2af9b RSI: 0000000000000008 RDI: ffffffffc0280068
RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed1025c2af9a
R10: ffff88812e157cd7 R11: 205d323130325420 R12: 0000000000000002
R13: ffffffffc0290488 R14: 0000000000000002 R15: ffffffffc0280040
FS: 00007fbc450dd740(0000) GS:ffff888420331000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffbfff805000d CR3: 000000010f624000 CR4: 00000000000006f0
Call Trace:
<TASK>
notifier_call_chain+0xc6/0x280
blocking_notifier_call_chain+0x60/0x90
__do_sys_delete_module.constprop.0+0x32a/0x4e0
do_syscall_64+0x5d/0xfa0
entry_SYSCALL_64_after_hwframe+0x76/0x7e
This is because the kprobe on ftrace does not correctly handles
the kprobe_ftrace_disabled flag set by ftrace_kill().
To prevent this error, check kprobe_ftrace_disabled in
__disarm_kprobe_ftrace() and skip all ftrace related operations.
Link: https://lore.kernel.org/all/176473947565.1727781.13110060700668331950.stgit@mhiramat.tok.corp.google.com/
Reported-by: Ye Bin <yebin10@huawei.com>
Closes: https://lore.kernel.org/all/20251125020536.2484381-1-yebin@huaweicloud.com/
Fixes: ae6aa16fdc16 ("kprobes: introduce ftrace based optimization")
Cc: stable@vger.kernel.org
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/kprobes.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/kernel/kprobes.c b/kernel/kprobes.c index ab25b4aa9095..025af57ad3ed 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -1178,6 +1178,10 @@ static int __disarm_kprobe_ftrace(struct kprobe *p, struct ftrace_ops *ops, int ret; lockdep_assert_held(&kprobe_mutex); + if (unlikely(kprobe_ftrace_disabled)) { + /* Now ftrace is disabled forever, disarm is already done. */ + return 0; + } if (*cnt == 1) { ret = unregister_ftrace_function(ops); |