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 5341DC148; Tue, 29 Apr 2025 17:49:05 +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=1745948945; cv=none; b=g3MIDdzXXy55n3CFsfaA+v+VesZLOVoVTuoc5DVk0StNc7oeX8+YqJ5Sd0cXt6owzF2MLChqi+gfELOEuSa7qyWclOt4ujjbmW7K78BsJB2NhnmQMUrlVC1Y5K6AdZY+5SSZxD6TNk0Q7/MIwTZ+b994nL1sj0oUCaqF9yfKSFQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745948945; c=relaxed/simple; bh=yiPk8fX33KCZT/9BmXKkaHRQ64uPbqhcf2nBqt0IAAk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=NPsEyZstHuwg51aJLJg1Li330Pwb6sN2RG19rznlaGDIfCg6+pjv83Hzxxuz2/aT5B+AyZFWwguIj45YzDue1Q3HunMd0Wic7F2dnTCG3KigBR8wsyNkMgIlnrvPN5PXDytliUnws/WKpL7bEaaljJrr6ZFB4yI0LtNER7y4TbY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ip34pW+q; 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="ip34pW+q" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AF371C4CEE3; Tue, 29 Apr 2025 17:49:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1745948945; bh=yiPk8fX33KCZT/9BmXKkaHRQ64uPbqhcf2nBqt0IAAk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ip34pW+q5i4PQXDl2iYs07P8jNqMgFTNmYPZ8N1poALyjq1paR9qlMrWurl/dBRhn pIInjTGHDjvCO3HmloP7Mk5rY/TFZKFJ4qt1yRD44/I4IbXPIMFuLbDQJqoCUncz5q IVtcVAZpQO9IfIqWXp3Uah9hWkNXuKt9Xc5tecmU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Masami Hiramatsu , Mathieu Desnoyers , Andrew Morton , Andrii Nakryiko , Mykyta Yatsenko , "Steven Rostedt (Google)" Subject: [PATCH 5.15 171/373] tracing: Fix filter string testing Date: Tue, 29 Apr 2025 18:40:48 +0200 Message-ID: <20250429161130.207325507@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250429161123.119104857@linuxfoundation.org> References: <20250429161123.119104857@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 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Steven Rostedt commit a8c5b0ed89a3f2c81c6ae0b041394e6eea0e7024 upstream. The filter string testing uses strncpy_from_kernel/user_nofault() to retrieve the string to test the filter against. The if() statement was incorrect as it considered 0 as a fault, when it is only negative that it faulted. Running the following commands: # cd /sys/kernel/tracing # echo "filename.ustring ~ \"/proc*\"" > events/syscalls/sys_enter_openat/filter # echo 1 > events/syscalls/sys_enter_openat/enable # ls /proc/$$/maps # cat trace Would produce nothing, but with the fix it will produce something like: ls-1192 [007] ..... 8169.828333: sys_openat(dfd: ffffffffffffff9c, filename: 7efc18359904, flags: 80000, mode: 0) Link: https://lore.kernel.org/all/CAEf4BzbVPQ=BjWztmEwBPRKHUwNfKBkS3kce-Rzka6zvbQeVpg@mail.gmail.com/ Cc: stable@vger.kernel.org Cc: Masami Hiramatsu Cc: Mathieu Desnoyers Cc: Andrew Morton Link: https://lore.kernel.org/20250417183003.505835fb@gandalf.local.home Fixes: 77360f9bbc7e5 ("tracing: Add test for user space strings when filtering on string pointers") Reported-by: Andrii Nakryiko Reported-by: Mykyta Yatsenko Signed-off-by: Steven Rostedt (Google) Signed-off-by: Greg Kroah-Hartman --- kernel/trace/trace_events_filter.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/kernel/trace/trace_events_filter.c +++ b/kernel/trace/trace_events_filter.c @@ -676,7 +676,7 @@ static __always_inline char *test_string kstr = ubuf->buffer; /* For safety, do not trust the string pointer */ - if (!strncpy_from_kernel_nofault(kstr, str, USTRING_BUF_SIZE)) + if (strncpy_from_kernel_nofault(kstr, str, USTRING_BUF_SIZE) < 0) return NULL; return kstr; } @@ -695,7 +695,7 @@ static __always_inline char *test_ustrin /* user space address? */ ustr = (char __user *)str; - if (!strncpy_from_user_nofault(kstr, ustr, USTRING_BUF_SIZE)) + if (strncpy_from_user_nofault(kstr, ustr, USTRING_BUF_SIZE) < 0) return NULL; return kstr;