From: Pavel Skripkin paskripkin@gmail.com
[ Upstream commit 471bec68457aaf981add77b4f590d65dd7da1059 ]
Syzbot reported that -1 is used as array index. The problem was in missing validation check.
hdw->unit_number is initialized with -1 and then if init table walk fails this value remains unchanged. Since code blindly uses this member for array indexing adding sanity check is the easiest fix for that.
hdw->workpoll initialization moved upper to prevent warning in __flush_work.
Reported-and-tested-by: syzbot+1a247e36149ffd709a9b@syzkaller.appspotmail.com
Fixes: d855497edbfb ("V4L/DVB (4228a): pvrusb2 to kernel 2.6.18") Signed-off-by: Pavel Skripkin paskripkin@gmail.com Signed-off-by: Hans Verkuil hverkuil-cisco@xs4all.nl Signed-off-by: Mauro Carvalho Chehab mchehab@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/media/usb/pvrusb2/pvrusb2-hdw.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/media/usb/pvrusb2/pvrusb2-hdw.c b/drivers/media/usb/pvrusb2/pvrusb2-hdw.c index 40535db585a0..b868a77a048c 100644 --- a/drivers/media/usb/pvrusb2/pvrusb2-hdw.c +++ b/drivers/media/usb/pvrusb2/pvrusb2-hdw.c @@ -2615,6 +2615,11 @@ struct pvr2_hdw *pvr2_hdw_create(struct usb_interface *intf, } while (0); mutex_unlock(&pvr2_unit_mtx);
+ INIT_WORK(&hdw->workpoll, pvr2_hdw_worker_poll); + + if (hdw->unit_number == -1) + goto fail; + cnt1 = 0; cnt2 = scnprintf(hdw->name+cnt1,sizeof(hdw->name)-cnt1,"pvrusb2"); cnt1 += cnt2; @@ -2626,8 +2631,6 @@ struct pvr2_hdw *pvr2_hdw_create(struct usb_interface *intf, if (cnt1 >= sizeof(hdw->name)) cnt1 = sizeof(hdw->name)-1; hdw->name[cnt1] = 0;
- INIT_WORK(&hdw->workpoll,pvr2_hdw_worker_poll); - pvr2_trace(PVR2_TRACE_INIT,"Driver unit number is %d, name is %s", hdw->unit_number,hdw->name);