From: Pavel Skripkin paskripkin@gmail.com
stable inclusion from stable-v5.10.121 commit a3304766d9384886e6d3092c776273526947a2e9 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I5L6CQ
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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[ 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 Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com Acked-by: Xie XiuQi xiexiuqi@huawei.com --- 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 3915d551d59e..fccd1798445d 100644 --- a/drivers/media/usb/pvrusb2/pvrusb2-hdw.c +++ b/drivers/media/usb/pvrusb2/pvrusb2-hdw.c @@ -2569,6 +2569,11 @@ 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; @@ -2580,8 +2585,6 @@ 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);