Re: [syzbot] WARNING: lock held when returning to user space in ieee80211_change_mac

[Johannes Berg]

On Sat, 2022-10-01 at 07:26 -0700, syzbot wrote:
> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    6627a2074d5c net/smc: Support SO_REUSEPORT
> git tree:       net-next
> console output: https://syzkaller.appspot.com/x/log.txt?x=10183a70880000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=d4d64087513b5aa1
> dashboard link: https://syzkaller.appspot.com/bug?extid=4ef359e6b423499fa4e1
> compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
> 
> Unfortunately, I don't have any reproducer for this issue yet.
> 
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/9ecb75606956/disk-6627a207.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/1073865fcb40/vmlinux-6627a207.xz
> 
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+4ef359e6b423499fa4e1@xxxxxxxxxxxxxxxxxxxxxxxxx
> 
> ================================================
> WARNING: lock held when returning to user space!
> 6.0.0-rc6-syzkaller-01407-g6627a2074d5c #0 Not tainted
> ------------------------------------------------
> syz-executor.3/10164 is leaving the kernel with locks still held!
> 1 lock held by syz-executor.3/10164:
>  #0: ffff888147acaa88 (&local->mtx){+.+.}-{3:3}, at: ieee80211_can_powered_addr_change net/mac80211/iface.c:217 [inline]
>  #0: ffff888147acaa88 (&local->mtx){+.+.}-{3:3}, at: ieee80211_change_mac+0x9b4/0xf40 net/mac80211/iface.c:264
> 

Uh, right. Pretty sure this will fix it once I merge it:

https://patchwork.kernel.org/project/linux-wireless/patch/Yx9LJFA7PDSRmb/M@kili/

johannes