From: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> mainline inclusion from mainline-v7.0-rc4 commit e113f0b46d19626ec15388bcb91432c9a4fd6261 category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/14968 CVE: CVE-2026-43409 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- 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@... 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> Conflicts: kernel/kprobes.c [Context conflict] Signed-off-by: Tengda Wu <wutengda@huaweicloud.com> --- kernel/kprobes.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 8f8679f9c012..29cf118ea988 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -1089,6 +1089,11 @@ static int __disarm_kprobe_ftrace(struct kprobe *p, struct ftrace_ops *ops, { int ret = 0; + if (unlikely(kprobe_ftrace_disabled)) { + /* Now ftrace is disabled forever, disarm is already done. */ + return 0; + } + if (*cnt == 1) { ret = unregister_ftrace_function(ops); if (WARN(ret < 0, "Failed to unregister kprobe-ftrace (%d)\n", ret)) -- 2.34.1