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 8D6211A1A6A; Tue, 7 May 2024 23:14:42 +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=1715123682; cv=none; b=XltMihuKPyJTLtpFaOAVpC3PDo8VxrYP7HnEEz5GxgJ4pkbpJkiimScFTQt2kNqK10YNL/coqC/InExtFUHbaoXd/rj7SQvqIcvu0glva15y53Iv7HM1/sOc7wTTJ4g5OjqgFqtrREXGZMYNC4dlQW6WYYhZoRWt3PTTtsD/j6Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715123682; c=relaxed/simple; bh=FFq1YsZ4lWDlVgX98/DsdDyntB51ZyHmLHMXwbuEUO4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=U9be/bxlIXzhcVpfCG0bcw5flnexUSpiHShUCvgqU4kN7P3n80JmXNw+ojs4bCWSYFIsZA8LiAEATjlUOEXwNge2GOEG4u5KATDhF9M9Ltb9PHK1BzCukOkOlTm7uXznxN+9I4xSdLhGdju2uj/ffU61wRLcddCsnYj28VyvZB4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=qakxCW2e; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="qakxCW2e" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 51C35C4AF17; Tue, 7 May 2024 23:14:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1715123682; bh=FFq1YsZ4lWDlVgX98/DsdDyntB51ZyHmLHMXwbuEUO4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qakxCW2ewMbjqW1a7ej3hFcYrZnwxGUpG2WVrDw7v6YemDixruuosnq+o/dwgVJ1v KlQqHFiiVV5a14msSq3ElNUrEPWmF4ysTkCK2bCBo+Tm4UAppAKkM2nt6Wtvpsq6Vy Yj2kST2dXeodLgC7ezJGz13U3g4DrvJoigC6/6lW9v7fo6RlXa1o25SqKc54WSoc5a 4jKYk3gr5WC4YhytF+6C4/ZuLsZMozpRK7fSE1TCeJPyBvv2N/dCXh9qNjdB4mLTET 6thSPjA7JEvNOUkMEskKbWGJMvfhAe2p9NaOGZy9Bl7L5i+4E+skFrDmS+JY25ITSl evJR7u2sw63/A== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Thanassis Avgerinos , Takashi Sakamoto , Sasha Levin , linux1394-devel@lists.sourceforge.net Subject: [PATCH AUTOSEL 4.19 3/4] firewire: nosy: ensure user_length is taken into account when fetching packet contents Date: Tue, 7 May 2024 19:14:34 -0400 Message-ID: <20240507231436.395448-3-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240507231436.395448-1-sashal@kernel.org> References: <20240507231436.395448-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 4.19.313 Content-Transfer-Encoding: 8bit From: Thanassis Avgerinos [ Upstream commit 38762a0763c10c24a4915feee722d7aa6e73eb98 ] Ensure that packet_buffer_get respects the user_length provided. If the length of the head packet exceeds the user_length, packet_buffer_get will now return 0 to signify to the user that no data were read and a larger buffer size is required. Helps prevent user space overflows. Signed-off-by: Thanassis Avgerinos Signed-off-by: Takashi Sakamoto Signed-off-by: Sasha Levin --- drivers/firewire/nosy.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/firewire/nosy.c b/drivers/firewire/nosy.c index ac85e03e88e16..f3784c054dd6e 100644 --- a/drivers/firewire/nosy.c +++ b/drivers/firewire/nosy.c @@ -161,10 +161,12 @@ packet_buffer_get(struct client *client, char __user *data, size_t user_length) if (atomic_read(&buffer->size) == 0) return -ENODEV; - /* FIXME: Check length <= user_length. */ + length = buffer->head->length; + + if (length > user_length) + return 0; end = buffer->data + buffer->capacity; - length = buffer->head->length; if (&buffer->head->data[length] < end) { if (copy_to_user(data, buffer->head->data, length)) -- 2.43.0