Commit b7c81f80 authored by Chengfeng Ye's avatar Chengfeng Ye Committed by Takashi Iwai
Browse files

firewire: fix potential uaf in outbound_phy_packet_callback() 



&e->event and e point to the same address, and &e->event could
be freed in queue_event. So there is a potential uaf issue if
we dereference e after calling queue_event(). Fix this by adding
a temporary variable to maintain e->client in advance, this can
avoid the potential uaf issue.

Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarChengfeng Ye <cyeaa@connect.ust.hk>
Signed-off-by: default avatarTakashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20220409041243.603210-2-o-takashi@sakamocchi.jp


Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent 31231092

drivers/firewire/core-cdev.c

+3 −1
Original line number Diff line number Diff line
@@ -1500,6 +1500,7 @@ static void outbound_phy_packet_callback(struct fw_packet *packet, 
{

	struct outbound_phy_packet_event *e =

		container_of(packet, struct outbound_phy_packet_event, p);

	struct client *e_client;



	switch (status) {

	/* expected: */
@@ -1516,9 +1517,10 @@ static void outbound_phy_packet_callback(struct fw_packet *packet, 
	}

	e->phy_packet.data[0] = packet->timestamp;



	e_client = e->client;

	queue_event(e->client, &e->event, &e->phy_packet,

		    sizeof(e->phy_packet) + e->phy_packet.length, NULL, 0);

	client_put(e->client);

	client_put(e_client);

}



static int ioctl_send_phy_packet(struct client *client, union ioctl_arg *arg)