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 EBB2E19307F for ; Sat, 23 Aug 2025 15:44:44 +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=1755963886; cv=none; b=elWtorTd+LMJsjiglgaB6CRsbVEGeAVzSiMfwN6QsFc9Rhrq0H9T/r9Hr86d6wNCKg0vBK0HfvG2y8bTcysTfJYdyJcIUa38ChsaLRMPuJg1PiIix+kf9A+VVDSf0BgFLyhS2ZHPI134UrQFjAhlPxiDkPECE+ZYGafl0p8TTg8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755963886; c=relaxed/simple; bh=8u2ZihtWk+xtpCJqlDCqUU0+Xvm7VIxkACwE3ezizBI=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=QDKWg9dUC5p/CCfiCu++Px+Gd7jl3+PVfwXBH79gVrPKkp8Iin32PF4EuRsCqupRu5dPeiGQSswyc3vgV1QS0suHCx8wv2rJSCIoRE7s9GC8+wJkG3N6R4tCjy97FlFxwQ3gc4EpTsJi5cYNOyaMnWY87MsPCPUkdSGI6JhHc3E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=kOCFERy4; 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="kOCFERy4" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 17BAFC4CEE7; Sat, 23 Aug 2025 15:44:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1755963884; bh=8u2ZihtWk+xtpCJqlDCqUU0+Xvm7VIxkACwE3ezizBI=; h=Subject:To:Cc:From:Date:From; b=kOCFERy4R2twax0RbDq6Gp6AYUAkn9ebvgQM70IMotLAz3Dkl2XT4F1c9KkU0llAi W6ok32YAdULTWAiqw3XWOXdx1d9aM/7iihYt5A0FsEVPpP+5TQ2ziTRNyxwi68UMqN 2NS2kk5wl8N65t1zI/YUMBx78ngo6v2VJbyCDhgA= Subject: FAILED: patch "[PATCH] tracing: Limit access to parser->buffer when trace_get_user" failed to apply to 6.1-stable tree To: pulehui@huawei.com,rostedt@goodmis.org Cc: From: Date: Sat, 23 Aug 2025 17:44:31 +0200 Message-ID: <2025082331-axis-politely-d9d3@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit The patch below does not apply to the 6.1-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y git checkout FETCH_HEAD git cherry-pick -x 6a909ea83f226803ea0e718f6e88613df9234d58 # git commit -s git send-email --to '' --in-reply-to '2025082331-axis-politely-d9d3@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 6a909ea83f226803ea0e718f6e88613df9234d58 Mon Sep 17 00:00:00 2001 From: Pu Lehui Date: Wed, 13 Aug 2025 04:02:32 +0000 Subject: [PATCH] tracing: Limit access to parser->buffer when trace_get_user failed When the length of the string written to set_ftrace_filter exceeds FTRACE_BUFF_MAX, the following KASAN alarm will be triggered: BUG: KASAN: slab-out-of-bounds in strsep+0x18c/0x1b0 Read of size 1 at addr ffff0000d00bd5ba by task ash/165 CPU: 1 UID: 0 PID: 165 Comm: ash Not tainted 6.16.0-g6bcdbd62bd56-dirty Hardware name: linux,dummy-virt (DT) Call trace: show_stack+0x34/0x50 (C) dump_stack_lvl+0xa0/0x158 print_address_description.constprop.0+0x88/0x398 print_report+0xb0/0x280 kasan_report+0xa4/0xf0 __asan_report_load1_noabort+0x20/0x30 strsep+0x18c/0x1b0 ftrace_process_regex.isra.0+0x100/0x2d8 ftrace_regex_release+0x484/0x618 __fput+0x364/0xa58 ____fput+0x28/0x40 task_work_run+0x154/0x278 do_notify_resume+0x1f0/0x220 el0_svc+0xec/0xf0 el0t_64_sync_handler+0xa0/0xe8 el0t_64_sync+0x1ac/0x1b0 The reason is that trace_get_user will fail when processing a string longer than FTRACE_BUFF_MAX, but not set the end of parser->buffer to 0. Then an OOB access will be triggered in ftrace_regex_release-> ftrace_process_regex->strsep->strpbrk. We can solve this problem by limiting access to parser->buffer when trace_get_user failed. Cc: stable@vger.kernel.org Link: https://lore.kernel.org/20250813040232.1344527-1-pulehui@huaweicloud.com Fixes: 8c9af478c06b ("ftrace: Handle commands when closing set_ftrace_filter file") Signed-off-by: Pu Lehui Signed-off-by: Steven Rostedt (Google) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 4283ed4e8f59..8d8935ed416d 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1816,7 +1816,7 @@ int trace_get_user(struct trace_parser *parser, const char __user *ubuf, ret = get_user(ch, ubuf++); if (ret) - return ret; + goto fail; read++; cnt--; @@ -1830,7 +1830,7 @@ int trace_get_user(struct trace_parser *parser, const char __user *ubuf, while (cnt && isspace(ch)) { ret = get_user(ch, ubuf++); if (ret) - return ret; + goto fail; read++; cnt--; } @@ -1848,12 +1848,14 @@ int trace_get_user(struct trace_parser *parser, const char __user *ubuf, while (cnt && !isspace(ch) && ch) { if (parser->idx < parser->size - 1) parser->buffer[parser->idx++] = ch; - else - return -EINVAL; + else { + ret = -EINVAL; + goto fail; + } ret = get_user(ch, ubuf++); if (ret) - return ret; + goto fail; read++; cnt--; } @@ -1868,11 +1870,15 @@ int trace_get_user(struct trace_parser *parser, const char __user *ubuf, /* Make sure the parsed string always terminates with '\0'. */ parser->buffer[parser->idx] = 0; } else { - return -EINVAL; + ret = -EINVAL; + goto fail; } *ppos += read; return read; +fail: + trace_parser_fail(parser); + return ret; } /* TODO add a seq_buf_to_buffer() */ diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 1dbf1d3cf2f1..be6654899cae 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -1292,6 +1292,7 @@ bool ftrace_event_is_function(struct trace_event_call *call); */ struct trace_parser { bool cont; + bool fail; char *buffer; unsigned idx; unsigned size; @@ -1299,7 +1300,7 @@ struct trace_parser { static inline bool trace_parser_loaded(struct trace_parser *parser) { - return (parser->idx != 0); + return !parser->fail && parser->idx != 0; } static inline bool trace_parser_cont(struct trace_parser *parser) @@ -1313,6 +1314,11 @@ static inline void trace_parser_clear(struct trace_parser *parser) parser->idx = 0; } +static inline void trace_parser_fail(struct trace_parser *parser) +{ + parser->fail = true; +} + extern int trace_parser_get_init(struct trace_parser *parser, int size); extern void trace_parser_put(struct trace_parser *parser); extern int trace_get_user(struct trace_parser *parser, const char __user *ubuf,