Module Name: src
Committed By: riastradh
Date: Tue Mar 15 00:05:18 UTC 2022
Modified Files:
src/sys/net: if_tun.c
Log Message:
tun(4): Fix bug introduced in previous locking change.
Now that tun_lock runs at IPL_NONE, taking it does not have the side
effect of disabling preemption, but pktq_enqueue assumes the caller
has disabled preemption so it can safely schedule a softint.
This isn't a problem in most physical network drivers because the
pktq_enqueue call happens from within the driver's softint context
anyway. But tun(4) is special -- here, the pktq_enqueue is triggered
by a userland write to the device, which is in thread context. So
let's just disable preemption in tunwrite.
Reported-by: syzbot+21c2cb300f1ec2162...@syzkaller.appspotmail.com
To generate a diff of this commit:
cvs rdiff -u -r1.171 -r1.172 src/sys/net/if_tun.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
