Re: [syzbot] [wireless?] KMSAN: uninit-value in skb_trim (2)

["Toke Høiland-Jørgensen" <toke@toke.dk>]

syzbot <syzbot+98afa303be379af6cdb2@syzkaller.appspotmail.com> writes:

> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit:    b446a2dae984 Merge tag 'linux_kselftest-fixes-6.11-rc3' of..
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=13eb467d980000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=305509ad8eb5f9b8
> dashboard link: https://syzkaller.appspot.com/bug?extid=98afa303be379af6cdb2
> compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
>
> Unfortunately, I don't have any reproducer for this issue yet.
>
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/49d96e53e1c4/disk-b446a2da.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/f05350d128a7/vmlinux-b446a2da.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/805c7d86a2db/bzImage-b446a2da.xz
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+98afa303be379af6cdb2@syzkaller.appspotmail.com

#syz test

diff --git a/drivers/net/wireless/ath/ath9k/hif_usb.c b/drivers/net/wireless/ath/ath9k/hif_usb.c
index 0c7841f95228..f77cb743ca06 100644
--- a/drivers/net/wireless/ath/ath9k/hif_usb.c
+++ b/drivers/net/wireless/ath/ath9k/hif_usb.c
@@ -755,7 +755,7 @@ static void ath9k_hif_usb_reg_in_cb(struct urb *urb)
                goto free_skb;
        default:
                skb_reset_tail_pointer(skb);
-               skb_trim(skb, 0);
+               __skb_trim(skb, 0);
 
                goto resubmit;
        }