From: Chengfeng Ye <cyeaa@xxxxxxxxxxxxxx>
&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@xxxxxxxxxxxxxxx>
Signed-off-by: Chengfeng Ye <cyeaa@xxxxxxxxxxxxxx>
Signed-off-by: Takashi Sakamoto <o-takashi@xxxxxxxxxxxxx>
---
drivers/firewire/core-cdev.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/firewire/core-cdev.c b/drivers/firewire/core-cdev.c
index 9f89c17730b1..708e417200f4 100644
--- a/drivers/firewire/core-cdev.c
+++ b/drivers/firewire/core-cdev.c
@@ -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)
--
2.34.1
