| From b7c81f80246fac44077166f3e07103affe6db8ff Mon Sep 17 00:00:00 2001 |
| From: Chengfeng Ye <cyeaa@connect.ust.hk> |
| Date: Sat, 9 Apr 2022 13:12:41 +0900 |
| Subject: firewire: fix potential uaf in outbound_phy_packet_callback() |
| |
| From: Chengfeng Ye <cyeaa@connect.ust.hk> |
| |
| commit b7c81f80246fac44077166f3e07103affe6db8ff upstream. |
| |
| &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: Chengfeng Ye <cyeaa@connect.ust.hk> |
| Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> |
| Link: https://lore.kernel.org/r/20220409041243.603210-2-o-takashi@sakamocchi.jp |
| Signed-off-by: Takashi Iwai <tiwai@suse.de> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| drivers/firewire/core-cdev.c | 4 +++- |
| 1 file changed, 3 insertions(+), 1 deletion(-) |
| |
| --- a/drivers/firewire/core-cdev.c |
| +++ b/drivers/firewire/core-cdev.c |
| @@ -1480,6 +1480,7 @@ static void outbound_phy_packet_callback |
| { |
| struct outbound_phy_packet_event *e = |
| container_of(packet, struct outbound_phy_packet_event, p); |
| + struct client *e_client; |
| |
| switch (status) { |
| /* expected: */ |
| @@ -1496,9 +1497,10 @@ static void outbound_phy_packet_callback |
| } |
| 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) |
