diff options
| author | Zheng Wang <zyytlz.wz@163.com> | 2023-03-18 16:50:23 +0800 |
|---|---|---|
| committer | Hans Verkuil <hverkuil-cisco@xs4all.nl> | 2023-04-11 17:10:10 +0200 |
| commit | 30cf57da176cca80f11df0d9b7f71581fe601389 (patch) | |
| tree | 730610a24c71562663c8abeecf45ebcad77db876 /drivers/media/pci/saa7134 | |
| parent | 5abda7a16698d4d1f47af1168d8fa2c640116b4a (diff) | |
media: saa7134: fix use after free bug in saa7134_finidev due to race condition
In saa7134_initdev, it will call saa7134_hwinit1. There are three
function invoking here: saa7134_video_init1, saa7134_ts_init1
and saa7134_vbi_init1.
All of them will init a timer with same function. Take
saa7134_video_init1 as an example. It'll bound &dev->video_q.timeout
with saa7134_buffer_timeout.
In buffer_activate, the timer funtcion is started.
If we remove the module or device which will call saa7134_finidev
to make cleanup, there may be a unfinished work. The
possible sequence is as follows, which will cause a
typical UAF bug.
Fix it by canceling the timer works accordingly before cleanup in
saa7134_finidev.
CPU0 CPU1
|saa7134_buffer_timeout
saa7134_finidev |
kfree(dev); |
|
| saa7134_buffer_next
| //use dev
Fixes: 1e7126b4a86a ("media: saa7134: Convert timers to use timer_setup()")
Signed-off-by: Zheng Wang <zyytlz.wz@163.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Diffstat (limited to 'drivers/media/pci/saa7134')
| -rw-r--r-- | drivers/media/pci/saa7134/saa7134-ts.c | 1 | ||||
| -rw-r--r-- | drivers/media/pci/saa7134/saa7134-vbi.c | 1 | ||||
| -rw-r--r-- | drivers/media/pci/saa7134/saa7134-video.c | 1 |
3 files changed, 3 insertions, 0 deletions
diff --git a/drivers/media/pci/saa7134/saa7134-ts.c b/drivers/media/pci/saa7134/saa7134-ts.c index 6a5053126237..437dbe5e75e2 100644 --- a/drivers/media/pci/saa7134/saa7134-ts.c +++ b/drivers/media/pci/saa7134/saa7134-ts.c @@ -300,6 +300,7 @@ int saa7134_ts_start(struct saa7134_dev *dev) int saa7134_ts_fini(struct saa7134_dev *dev) { + del_timer_sync(&dev->ts_q.timeout); saa7134_pgtable_free(dev->pci, &dev->ts_q.pt); return 0; } diff --git a/drivers/media/pci/saa7134/saa7134-vbi.c b/drivers/media/pci/saa7134/saa7134-vbi.c index 3f0b0933eed6..3e773690468b 100644 --- a/drivers/media/pci/saa7134/saa7134-vbi.c +++ b/drivers/media/pci/saa7134/saa7134-vbi.c @@ -185,6 +185,7 @@ int saa7134_vbi_init1(struct saa7134_dev *dev) int saa7134_vbi_fini(struct saa7134_dev *dev) { /* nothing */ + del_timer_sync(&dev->vbi_q.timeout); return 0; } diff --git a/drivers/media/pci/saa7134/saa7134-video.c b/drivers/media/pci/saa7134/saa7134-video.c index c5e68f33640f..56b4481a40e6 100644 --- a/drivers/media/pci/saa7134/saa7134-video.c +++ b/drivers/media/pci/saa7134/saa7134-video.c @@ -1743,6 +1743,7 @@ int saa7134_video_init1(struct saa7134_dev *dev) void saa7134_video_fini(struct saa7134_dev *dev) { + del_timer_sync(&dev->video_q.timeout); /* free stuff */ saa7134_pgtable_free(dev->pci, &dev->video_q.pt); saa7134_pgtable_free(dev->pci, &dev->vbi_q.pt); |