diff options
| author | Ricardo B. Marliere <[email protected]> | 2023-10-13 01:09:12 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <[email protected]> | 2024-01-25 15:27:32 -0800 |
| commit | 30773ea47d41773f9611ffb4ebc9bda9d19a9e7e (patch) | |
| tree | bdba8ae841c084430aee23fa2de9c9ee6fbcf27d | |
| parent | 4019c809688dabd8be7a9464fa08cbe8652c0bda (diff) | |
| download | linux-30773ea47d41773f9611ffb4ebc9bda9d19a9e7e.tar.gz | |
media: pvrusb2: fix use after free on context disconnection
[ Upstream commit ded85b0c0edd8f45fec88783d7555a5b982449c1 ]
Upon module load, a kthread is created targeting the
pvr2_context_thread_func function, which may call pvr2_context_destroy
and thus call kfree() on the context object. However, that might happen
before the usb hub_event handler is able to notify the driver. This
patch adds a sanity check before the invalid read reported by syzbot,
within the context disconnection call stack.
Reported-and-tested-by: [email protected]
Closes: https://lore.kernel.org/all/[email protected]/
Fixes: e5be15c63804 ("V4L/DVB (7711): pvrusb2: Fix race on module unload")
Signed-off-by: Ricardo B. Marliere <[email protected]>
Acked-by: Mike Isely <[email protected]>
Signed-off-by: Hans Verkuil <[email protected]>
Signed-off-by: Mauro Carvalho Chehab <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
| -rw-r--r-- | drivers/media/usb/pvrusb2/pvrusb2-context.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/media/usb/pvrusb2/pvrusb2-context.c b/drivers/media/usb/pvrusb2/pvrusb2-context.c index 14170a5d72b350..1764674de98bc0 100644 --- a/drivers/media/usb/pvrusb2/pvrusb2-context.c +++ b/drivers/media/usb/pvrusb2/pvrusb2-context.c @@ -268,7 +268,8 @@ void pvr2_context_disconnect(struct pvr2_context *mp) { pvr2_hdw_disconnect(mp->hdw); mp->disconnect_flag = !0; - pvr2_context_notify(mp); + if (!pvr2_context_shutok()) + pvr2_context_notify(mp); } |