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 5163828980D; Wed, 7 May 2025 19:08:28 +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=1746644908; cv=none; b=mgWS9pWMRry2JeyKBGL8JEKBvs3cnnpGaDwaT1vimb+edGSaICUrO1NJkoAVhotSvOJV1f2xHbaxsbCfaaK6mShzcAPdasKn1zy0IKwkuv917Q0pulasLacBCLGLtEzqmOtyO44EMiTyPvj1J2/pOBR0UVG6hkp7JzyJ+a5xiMg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746644908; c=relaxed/simple; bh=n1EqzErsrx6JdiczuZm2wwZf5SktkZm2/U60JqwEHCA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ORmf7AuMPS7FbD/6en0RIJlbUQD323iZdtHudcm1FpOu/hwfpeFwHzV430Ai9K/1SZEcwAuCb3XMTS1zm6Upx0uXLtvam9uaYq4+VLkBji/OisuftUHSTKW82KlZIvvA05daMcVDQg8FipnbSlD0aFM9Bva9zg6u7ya8m5RZWJA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=0RVvWxIn; 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="0RVvWxIn" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C753AC4CEF3; Wed, 7 May 2025 19:08:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1746644908; bh=n1EqzErsrx6JdiczuZm2wwZf5SktkZm2/U60JqwEHCA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=0RVvWxInlWK5C/fDdYpU+++VRUJTRa5LfckOGIyqzDTvK6WlfyNH9RQNZiYxO65oU k0yc9XS4AuQqfgBPROEAysojgXwIX/i03n/tNnNKxZwOARXg7gBEfLVV3a+ruqslcl 1X6ErBzrZOp67Krl6mZxKyJrNn9Zs/Fs7B2jS+JA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot+c8cd2d2c412b868263fb@syzkaller.appspotmail.com, Steven Rostedt , Jeongjun Park Subject: [PATCH 6.6 032/129] tracing: Fix oob write in trace_seq_to_buffer() Date: Wed, 7 May 2025 20:39:28 +0200 Message-ID: <20250507183814.828508744@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250507183813.500572371@linuxfoundation.org> References: <20250507183813.500572371@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jeongjun Park commit f5178c41bb43444a6008150fe6094497135d07cb upstream. syzbot reported this bug: ================================================================== BUG: KASAN: slab-out-of-bounds in trace_seq_to_buffer kernel/trace/trace.c:1830 [inline] BUG: KASAN: slab-out-of-bounds in tracing_splice_read_pipe+0x6be/0xdd0 kernel/trace/trace.c:6822 Write of size 4507 at addr ffff888032b6b000 by task syz.2.320/7260 CPU: 1 UID: 0 PID: 7260 Comm: syz.2.320 Not tainted 6.15.0-rc1-syzkaller-00301-g3bde70a2c827 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:408 [inline] print_report+0xc3/0x670 mm/kasan/report.c:521 kasan_report+0xe0/0x110 mm/kasan/report.c:634 check_region_inline mm/kasan/generic.c:183 [inline] kasan_check_range+0xef/0x1a0 mm/kasan/generic.c:189 __asan_memcpy+0x3c/0x60 mm/kasan/shadow.c:106 trace_seq_to_buffer kernel/trace/trace.c:1830 [inline] tracing_splice_read_pipe+0x6be/0xdd0 kernel/trace/trace.c:6822 .... ================================================================== It has been reported that trace_seq_to_buffer() tries to copy more data than PAGE_SIZE to buf. Therefore, to prevent this, we should use the smaller of trace_seq_used(&iter->seq) and PAGE_SIZE as an argument. Link: https://lore.kernel.org/20250422113026.13308-1-aha310510@gmail.com Reported-by: syzbot+c8cd2d2c412b868263fb@syzkaller.appspotmail.com Fixes: 3c56819b14b0 ("tracing: splice support for tracing_pipe") Suggested-by: Steven Rostedt Signed-off-by: Jeongjun Park Signed-off-by: Steven Rostedt (Google) Signed-off-by: Greg Kroah-Hartman --- kernel/trace/trace.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -7027,13 +7027,14 @@ static ssize_t tracing_splice_read_pipe( /* Copy the data into the page, so we can start over. */ ret = trace_seq_to_buffer(&iter->seq, page_address(spd.pages[i]), - trace_seq_used(&iter->seq)); + min((size_t)trace_seq_used(&iter->seq), + PAGE_SIZE)); if (ret < 0) { __free_page(spd.pages[i]); break; } spd.partial[i].offset = 0; - spd.partial[i].len = trace_seq_used(&iter->seq); + spd.partial[i].len = ret; trace_seq_init(&iter->seq); }