diff options
| author | Mike Isely <isely@pobox.com> | 2008-04-07 09:22:43 +0400 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@infradead.org> | 2008-04-24 21:09:48 +0400 |
| commit | 97f26ff6049a7fff5460cebe392ad1d699dc434c (patch) | |
| tree | 8baf83788707e1488918ba00c7430b6f7b0a9d45 | |
| parent | e5be15c63804e05b5a94197524023702a259e308 (diff) | |
| download | linux-97f26ff6049a7fff5460cebe392ad1d699dc434c.tar.xz | |
V4L/DVB (7712): pvrusb2: Close connect/disconnect race
If a disconnect happens before initialization is completed, the
pvrusb2 driver can accidentally touch dangling pointers. The whole
initialization function must be protected by the big_lock, and once
inside that lock, the initialization function should abort if it is
discovered that a disconnect has already taken place.
Signed-off-by: Mike Isely <isely@pobox.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
| -rw-r--r-- | drivers/media/video/pvrusb2/pvrusb2-hdw.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/drivers/media/video/pvrusb2/pvrusb2-hdw.c b/drivers/media/video/pvrusb2/pvrusb2-hdw.c index 4f6bb58ca5fc..f907a56c587d 100644 --- a/drivers/media/video/pvrusb2/pvrusb2-hdw.c +++ b/drivers/media/video/pvrusb2/pvrusb2-hdw.c @@ -1854,10 +1854,19 @@ int pvr2_hdw_initialize(struct pvr2_hdw *hdw, void *callback_data) { LOCK_TAKE(hdw->big_lock); do { + if (hdw->flag_disconnected) { + /* Handle a race here: If we're already + disconnected by this point, then give up. If we + get past this then we'll remain connected for + the duration of initialization since the entire + initialization sequence is now protected by the + big_lock. */ + break; + } hdw->state_data = callback_data; hdw->state_func = callback_func; + pvr2_hdw_setup(hdw); } while (0); LOCK_GIVE(hdw->big_lock); - pvr2_hdw_setup(hdw); return hdw->flag_init_ok; } |