diff options
| author | Edward Adam Davis <eadavis@qq.com> | 2024-02-16 10:30:47 +0300 |
|---|---|---|
| committer | Hans Verkuil <hverkuil-cisco@xs4all.nl> | 2024-02-28 18:00:33 +0300 |
| commit | 0a0b79ea55de8514e1750884e5fec77f9fdd01ee (patch) | |
| tree | b89fa332e43e10b8db07135da5a0c55168a23b02 | |
| parent | c5b9b85a60652b89500bba1325070b6f838626f4 (diff) | |
| download | linux-0a0b79ea55de8514e1750884e5fec77f9fdd01ee.tar.xz | |
media: pvrusb2: fix uaf in pvr2_context_set_notify
[Syzbot reported]
BUG: KASAN: slab-use-after-free in pvr2_context_set_notify+0x2c4/0x310 drivers/media/usb/pvrusb2/pvrusb2-context.c:35
Read of size 4 at addr ffff888113aeb0d8 by task kworker/1:1/26
CPU: 1 PID: 26 Comm: kworker/1:1 Not tainted 6.8.0-rc1-syzkaller-00046-gf1a27f081c1f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
Workqueue: usb_hub_wq hub_event
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106
print_address_description mm/kasan/report.c:377 [inline]
print_report+0xc4/0x620 mm/kasan/report.c:488
kasan_report+0xda/0x110 mm/kasan/report.c:601
pvr2_context_set_notify+0x2c4/0x310 drivers/media/usb/pvrusb2/pvrusb2-context.c:35
pvr2_context_notify drivers/media/usb/pvrusb2/pvrusb2-context.c:95 [inline]
pvr2_context_disconnect+0x94/0xb0 drivers/media/usb/pvrusb2/pvrusb2-context.c:272
Freed by task 906:
kasan_save_stack+0x33/0x50 mm/kasan/common.c:47
kasan_save_track+0x14/0x30 mm/kasan/common.c:68
kasan_save_free_info+0x3f/0x60 mm/kasan/generic.c:640
poison_slab_object mm/kasan/common.c:241 [inline]
__kasan_slab_free+0x106/0x1b0 mm/kasan/common.c:257
kasan_slab_free include/linux/kasan.h:184 [inline]
slab_free_hook mm/slub.c:2121 [inline]
slab_free mm/slub.c:4299 [inline]
kfree+0x105/0x340 mm/slub.c:4409
pvr2_context_check drivers/media/usb/pvrusb2/pvrusb2-context.c:137 [inline]
pvr2_context_thread_func+0x69d/0x960 drivers/media/usb/pvrusb2/pvrusb2-context.c:158
[Analyze]
Task A set disconnect_flag = !0, which resulted in Task B's condition being met
and releasing mp, leading to this issue.
[Fix]
Place the disconnect_flag assignment operation after all code in pvr2_context_disconnect()
to avoid this issue.
Reported-and-tested-by: syzbot+ce750e124675d4599449@syzkaller.appspotmail.com
Fixes: e5be15c63804 ("V4L/DVB (7711): pvrusb2: Fix race on module unload")
Signed-off-by: Edward Adam Davis <eadavis@qq.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
| -rw-r--r-- | drivers/media/usb/pvrusb2/pvrusb2-context.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/media/usb/pvrusb2/pvrusb2-context.c b/drivers/media/usb/pvrusb2/pvrusb2-context.c index 58f2f3ff10ee..73c95ba2328a 100644 --- a/drivers/media/usb/pvrusb2/pvrusb2-context.c +++ b/drivers/media/usb/pvrusb2/pvrusb2-context.c @@ -267,9 +267,9 @@ static void pvr2_context_exit(struct pvr2_context *mp) void pvr2_context_disconnect(struct pvr2_context *mp) { pvr2_hdw_disconnect(mp->hdw); - mp->disconnect_flag = !0; if (!pvr2_context_shutok()) pvr2_context_notify(mp); + mp->disconnect_flag = !0; } |