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 8F4791FF5EC; Wed, 7 May 2025 18:53:15 +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=1746643995; cv=none; b=UVb89em/84o4ic5MaIkxRei6cGIzCf7751++t/scnc4DEeCK21JjGtgZIHbI5UBZRt89LemHDQegUVr/qd0htVHdkkmeAcZNg/usc9YqHHbnoBdYymDt159OOFwm1BufSKTbWjeaqMVIphHcZPOIr+KzBRUuAv7/tiyNJP2aY+U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746643995; c=relaxed/simple; bh=/3lGFrr0L8jp1aaVmAi+NavMdGLQghSMcaunZegGoRA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=KxCooeUdYyOYU0rrK3jdGFHR1cDPF2rch16juC/MVkyHSBxdOeKpw6myR5JM5RIKSM/ntIlUCATvq5lHHozlaiIN1ZEL3x93JV4jD6TKxlGjIXbr4uyRfLpKiqLeekMOVyWBbyrGiYq3S1sTh8Sq6KHoOIA0ZJKebjF8BZFnR7I= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ZeIFJ0Q8; 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="ZeIFJ0Q8" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 204AEC4CEE2; Wed, 7 May 2025 18:53:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1746643995; bh=/3lGFrr0L8jp1aaVmAi+NavMdGLQghSMcaunZegGoRA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZeIFJ0Q8x0/HdZJsL69BcVzelEEb1++t2NZsG64kEIqaKTKekrub9gUh2D8Bya8n9 M2MLRB31SA58HPz6Bdy7IsQTF3z3aW2+3USpkJXlcw7yBAmbKi4GqtAhSyskEyArzP h2p6iT01TdPdsz3R5auzqcjydmnj8SerXYHniLNQ= 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 6.14 046/183] tracing: Fix oob write in trace_seq_to_buffer() Date: Wed, 7 May 2025 20:38:11 +0200 Message-ID: <20250507183826.558682038@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250507183824.682671926@linuxfoundation.org> References: <20250507183824.682671926@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 6.14-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 @@ -6682,13 +6682,14 @@ 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); }