From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 93965823DD; Mon, 23 Mar 2026 14:18:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774275500; cv=none; b=ZMOgGs/ZlS83YxvE3dbk6+pSy3VG6Qodrreiwni2O30OnxsAzHz5xUd7ouAxyfqD4onN6ZkpvsxymWBC0NGuQwUvZSbUJQBouDfMrR4wpZgaMTByLCadhvlTI51p3pwhABHV7lgFJZ7pb4nKbjLH+2PLIaBmqTDLm3fK1xnEvEg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774275500; c=relaxed/simple; bh=DsQ/gYTnYDiLc7pAIfDtQls7mgyOamb4XgEgqvSJBT4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=dUd5YEXQwPxooc5/aXLxsOnNrRixTKuIxy3H7DCGr+nHmxTb0NEDk66jNE29RzBqK6d20kYLvDty+yiqmKnROiHLoVqLVnN3EGXd3LFJkWtUNveqLB7E9VnldaGrr/JF602UILCJLCmNG588xl02kuKtgScr95zLTD655b8L0Iw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=iA101lB3; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="iA101lB3" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 25A9CC4CEF7; Mon, 23 Mar 2026 14:18:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1774275500; bh=DsQ/gYTnYDiLc7pAIfDtQls7mgyOamb4XgEgqvSJBT4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=iA101lB3TmPhG8g9GUx5AovLFaHEYflOuGTIwIBOh0JEpmTNlGm3emG+Vz5eU+ckZ HKBAEMvjpjhA9xhpIMEBeazAxboSJB8uDkFw2U3VEfwXUE8IJsB84VfVTWgyjLyjHN s1PpGGXl+Mu5iFvAWD454Kq09XIxYDLtb3TXSAXA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Ye Bin , "Masami Hiramatsu (Google)" , "Steven Rostedt (Google)" Subject: [PATCH 6.12 124/460] kprobes: avoid crash when rmmod/insmod after ftrace killed Date: Mon, 23 Mar 2026 14:42:00 +0100 Message-ID: <20260323134529.666448793@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260323134526.647552166@linuxfoundation.org> References: <20260323134526.647552166@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Masami Hiramatsu (Google) commit e113f0b46d19626ec15388bcb91432c9a4fd6261 upstream. 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: 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 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) Acked-by: Steven Rostedt (Google) Signed-off-by: Greg Kroah-Hartman --- kernel/kprobes.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -1113,6 +1113,10 @@ static int __disarm_kprobe_ftrace(struct 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);