From: Pavel Skripkin <paskripkin@gmail.com> stable inclusion from stable-v4.19.247 commit a3660e06675bccec4bf149c7229ea1d491ba10d7 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IBP6VC CVE: CVE-2022-49478 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ 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: Gu Bowen <gubowen5@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 fcb201a40920..3fb2cfe583e8 100644 --- a/drivers/media/usb/pvrusb2/pvrusb2-hdw.c +++ b/drivers/media/usb/pvrusb2/pvrusb2-hdw.c @@ -2561,6 +2561,11 @@ 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; @@ -2572,8 +2577,6 @@ 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); -- 2.25.1