From 1310fc3538dcc375a2f46ef0a438512c2ca32827 Mon Sep 17 00:00:00 2001 From: Pavel Skripkin Date: Fri, 15 Apr 2022 23:24:48 +0200 Subject: [PATCH] media: pvrusb2: fix array-index-out-of-bounds in pvr2_i2c_core_init [ 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 Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Sasha Levin --- 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 2f00679f65a0..11e7fcfc3f19 100644 --- a/drivers/media/usb/pvrusb2/pvrusb2-hdw.c +++ b/drivers/media/usb/pvrusb2/pvrusb2-hdw.c @@ -2570,6 +2570,11 @@ 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; @@ -2581,8 +2586,6 @@ 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);