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 A49D0225A40; Mon, 2 Jun 2025 14:28:09 +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=1748874489; cv=none; b=GnVPALzyz90Tacv40oQZgHywhOY3MxiMrfVHpfgJfY+XbkPG5YQVSVsw2L3Hns7g75o4BETlZSL0B2G05g4ph37tcF3SQ9ZE0LEeKxCK20QG5va0wnDju0fZS5eJYrx/DkHp/ma0Jd91F/bR2CpBreNCSc0fVuMtepgSJik9Npk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748874489; c=relaxed/simple; bh=ud7fEMue1kosV8YbUD4AKwpocqQBLbLT0mnPykdACj0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=RbcXauX+c5aTRmFrHYFjdVmrBqrRsbt7iFhY7w/nFyvF9eacMzLTN46YlcOZneNGoDkL9GUccc/AsAftaVVOnBDVAefjpZ5CBZa/5lpYyRntvqgKq3MlbLAC3SJCxChvpinPEVThVZY+cX7jVJRszuLQfnRO+aZAFTBF3aqakkA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=EHBDfmQU; 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="EHBDfmQU" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 39528C4CEEB; Mon, 2 Jun 2025 14:28:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1748874489; bh=ud7fEMue1kosV8YbUD4AKwpocqQBLbLT0mnPykdACj0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EHBDfmQU5B68g4UqOPJ/rsVjZZKC94scPfY4dn0Qbu8OOjClceOK8NkJpcRWNKmYN h95AFcoKZEEYU+JlhFNY48tTWVjD5QB7CiHEnp727xQ7qQTZeGgbYHT/mvmnFdUSjQ HrKGZjRdJTBf4hyFvOjftCe6nQshCTr+65w1310Q= 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 5.4 009/204] tracing: Fix oob write in trace_seq_to_buffer() Date: Mon, 2 Jun 2025 15:45:42 +0200 Message-ID: <20250602134255.842400124@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250602134255.449974357@linuxfoundation.org> References: <20250602134255.449974357@linuxfoundation.org> User-Agent: quilt/0.68 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 5.4-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 @@ -6331,13 +6331,14 @@ 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); }