From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793208072; b=CB6PjD9TSrl4ouYL9wCF6OGW2TcFQA3fvgvv2mAie4czLreYSEpX/ujE/cXKmP2bp7/4 Vmq8DyjFAeGddr0vOd8Ds67oVHPgS7pN1XyX+sfDC6xAq54J5q5TG97zP1GRGJ0wtU9Hy n0mbr3X/f2gHH5mHhGqftccsr7MYZPAfoHm/IVVgH3PF8P8Mt6wel1aTl1D9ALUkmDgsa QQts35FU7lxgSD3zU4saql43xeFTOGspw02HkUju8zDjRjOqdDL5H98nRzo5jhbXwCFyg d5ew0Jo5NIG9W5nUmW/d4ht4afaUMUurhE76QX/crkQ3ukJ+4bRlUISPLVHQhaB+3Jg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793208072; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=UQzGCv72SEI1qqYua13zvgXgETPuHVMgWH22FHWmqx0=; b=l+9MRKfKzpMt4cpDH2qKTnV+9VRgFktXp5/JlyMs88mEhHep6ZGwsT31rj0dj5LHVGE4 i0/jsYvs5lDINT01pt7gpy9ZIrH+uk2iL9Rn/CzoXAFWcsCsR+0Idypx7mWVddLx60Zk/ 90IXuxQBuCd208mPaoCV0tHvQS93zv4rY9ws7Kc1FB79u0LFZuqrDmfWf5TOJ7cColq1g zT+G50361rfp6K4iD8W4aTvX9reeHcDm2yyB4nUweEl/HbYYDEJXuRBYLDEuyvWsGF3CE l6b1LiRzaogz0A0Gi2lOcRDXGX153Z59U+htHMWgYXHgda6lQZI8T0SiYCa6ghIwMog== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=X5H8tNSu; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7D8D6606A31D; Wed, 28 Oct 2026 17:21:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=X5H8tNSu Received: by smtp.kernel.org (Postfix) with ESMTPSA id A64301F01825; Wed, 28 Oct 2026 17:21:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793208072; bh=UQzGCv72SEI1qqYua13zvgXgETPuHVMgWH22FHWmqx0=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=X5H8tNSunI1Hh5hFSG/qlshf0rHVOsJOnBDnLmo8SLiuvLY9Fa3Ou6JLueY1wNWw9 uSCocN7uaAi9Vmv9Rek1eDcgQ/CngU+pnoAyv5eHtCdYesjyoFhZzbLX0eqA3GOQdN kz54XujkJz1uToMW2ed6qcPrI7I/ist84J53sHrw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Gavin Inglis , Aaron Ahmed , Steven Rostedt Subject: [PATCH 6.12 239/247] ftrace: Initialize modname and offset in print_rec() Date: Wed, 28 Oct 2026 18:00:42 +0100 Message-ID: <20261028165953.081460666@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261028165947.349197979@linuxfoundation.org> References: <20261028165947.349197979@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: patches@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Aaron Ahmed commit e1f339ff3b83857b93baf8b88186275a413d445e upstream. print_rec() leaves 'modname' and 'offset' uninitialized and kallsyms_lookup() only sets them on success. When the lookup fails like when a module is being loaded or unloaded, 'modname' holds a garbage value, passes the 'if (modname)' check, and is dereferenced by seq_printf(). Oops: general protection fault RIP: 0010:string+0x48/0xe0 Call Trace: vsnprintf+0x1f5/0x650 seq_printf+0x8e/0xb0 print_rec+0x6c/0xc0 t_show+0x4c/0x440 seq_read_iter+0x119/0x480 This can be triggered by reading available_filter_functions while a module is being loaded or unloaded. Initialize both variables so a failed lookup skips the module name. Cc: stable@vger.kernel.org Fixes: b39181f7c690 ("ftrace: Add FTRACE_MCOUNT_MAX_OFFSET to avoid adding weak function") Link: https://patch.msgid.link/20261016230403.4916-1-aarnahmd@amazon.com Tested-by: Gavin Inglis Signed-off-by: Aaron Ahmed Signed-off-by: Steven Rostedt Signed-off-by: Greg Kroah-Hartman --- kernel/trace/ftrace.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -4316,9 +4316,9 @@ subsys_initcall(ftrace_check_for_weak_fu static int print_rec(struct seq_file *m, unsigned long ip) { - unsigned long offset; + unsigned long offset = 0; char str[KSYM_SYMBOL_LEN]; - char *modname; + char *modname = NULL; const char *ret; ret = kallsyms_lookup(ip, NULL, &offset, &modname, str);