Commit 0dde91a7 authored by Thanassis Avgerinos's avatar Thanassis Avgerinos Committed by openeuler-sync-bot
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firewire: nosy: ensure user_length is taken into account when fetching packet contents 

mainline inclusion
from mainline-v6.9-rc7
commit 38762a0763c10c24a4915feee722d7aa6e73eb98
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9OZA3
CVE: CVE-2024-27401

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=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: default avatarThanassis Avgerinos <thanassis.avgerinos@gmail.com>
Signed-off-by: default avatarTakashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: default avatarHongbo Li <lihongbo22@huawei.com>
(cherry picked from commit 607d4cfc)
parent 42514171

drivers/firewire/nosy.c

+4 −2
Original line number Diff line number Diff line
@@ -148,10 +148,12 @@ 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))