general protection fault in ieee80211_subif_start_xmit

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 87335852 Linux 4.14.209
git tree: linux-4.14.y
console output: https://syzkaller.appspot.com/x/log.txt?x=17323da5500000
kernel config: https://syzkaller.appspot.com/x/.config?x=77df3f7a7cfbd2e6
dashboard link: https://syzkaller.appspot.com/bug?extid=fcbcd11cca8dd50a7096
compiler: gcc (GCC) 10.1.0-syz 20200507
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1376baae500000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+fcbcd1...@syzkaller.appspotmail.com

systemd-journald[4615]: /dev/kmsg buffer overrun, some messages lost.
wlan1: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
ieee80211 phy11: mac80211_hwsim_bss_info_changed(changed=0xe vif->addr=02:00:00:00:0b:00)
general protection fault: 0000 [#1] PREEMPT SMP KASAN
Modules linked in:
CPU: 1 PID: 9901 Comm: systemd-udevd Not tainted 4.14.209-syzkaller #0
wlan1: Creating new IBSS network, BSSID 50:50:50:50:50:50
ieee80211 phy3: mac80211_hwsim_config (freq=2412(2412 - 0)/noht idle=0 ps=0 smps=static)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff88808fd421c0 task.stack: ffff8880a3968000
RIP: 0010:ieee80211_multicast_to_unicast net/mac80211/tx.c:3680 [inline]
RIP: 0010:ieee80211_subif_start_xmit+0x1f4/0xe00 net/mac80211/tx.c:3764
RSP: 0018:ffff8880ba507528 EFLAGS: 00010202
ieee80211 phy3: mac80211_hwsim_config (freq=2412(2412 - 0)/noht idle=0 ps=0 smps=static)
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 000000000000003b RSI: ffff8880af1d1900 RDI: 00000000000001d8
RBP: ffff888092c39e80 R08: ffffffff8b9bfe58 R09: 000000000004250e
R10: ffff88808fd42b38 R11: ffff88808fd421c0 R12: 00000000c7464000
R13: ffff88808fc60d42 R14: 1ffff110174a0edc R15: ffff8880af1d1900
FS: 00007f97441f78c0(0000) GS:ffff8880ba500000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9743bb0130 CR3: 00000000a90f7000 CR4: 00000000001406e0
ieee80211 phy11: ERP_CTS_PROT: 0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<IRQ>
ieee80211 phy3: mac80211_hwsim_bss_info_changed(changed=0x4000 vif->addr=02:00:00:00:03:00)
ieee80211 phy11: ERP_PREAMBLE: 0
__netdev_start_xmit include/linux/netdevice.h:4039 [inline]
netdev_start_xmit include/linux/netdevice.h:4048 [inline]
xmit_one net/core/dev.c:3005 [inline]
dev_hard_start_xmit+0x188/0x890 net/core/dev.c:3021
sch_direct_xmit+0x251/0x500 net/sched/sch_generic.c:186
ieee80211 phy3: mac80211_hwsim_conf_tx (queue=0 txop=0 cw_min=15 cw_max=1023 aifs=2)
__dev_xmit_skb net/core/dev.c:3214 [inline]
__dev_queue_xmit+0x1ab0/0x2480 net/core/dev.c:3489
ieee80211 phy3: mac80211_hwsim_conf_tx (queue=1 txop=0 cw_min=15 cw_max=1023 aifs=2)
ieee80211 phy11: ERP_SLOT: 0
neigh_resolve_output+0x4e5/0x870 net/core/neighbour.c:1369
neigh_output include/net/neighbour.h:500 [inline]
ip6_finish_output2+0xf48/0x1f10 net/ipv6/ip6_output.c:120
ip6_finish_output+0x60c/0xaf0 net/ipv6/ip6_output.c:154
NF_HOOK_COND include/linux/netfilter.h:239 [inline]
ip6_output+0x1c5/0x660 net/ipv6/ip6_output.c:171
dst_output include/net/dst.h:470 [inline]
NF_HOOK include/linux/netfilter.h:250 [inline]
mld_sendpack+0x5fe/0xea0 net/ipv6/mcast.c:1660
mld_send_cr net/ipv6/mcast.c:1956 [inline]
mld_ifc_timer_expire+0x57c/0xcd0 net/ipv6/mcast.c:2455
call_timer_fn+0x14a/0x650 kernel/time/timer.c:1280
expire_timers+0x232/0x4d0 kernel/time/timer.c:1319
__run_timers kernel/time/timer.c:1637 [inline]
run_timer_softirq+0x1d5/0x5a0 kernel/time/timer.c:1650
__do_softirq+0x254/0xa1d kernel/softirq.c:288
invoke_softirq kernel/softirq.c:368 [inline]
irq_exit+0x193/0x240 kernel/softirq.c:409
exiting_irq arch/x86/include/asm/apic.h:648 [inline]
smp_apic_timer_interrupt+0x141/0x5e0 arch/x86/kernel/apic/apic.c:1102
apic_timer_interrupt+0x93/0xa0 arch/x86/entry/entry_64.S:793
</IRQ>
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:779 [inline]
RIP: 0010:lock_acquire+0x1ec/0x3f0 kernel/locking/lockdep.c:4001
RSP: 0018:ffff8880a396fc30 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff10
RAX: 1ffffffff11e1231 RBX: ffff88808fd421c0 RCX: 000000000000488e
RDX: dffffc0000000000 RSI: 0000000000000001 RDI: 0000000000000286
RBP: ffff8880929be150 R08: ffffffff8b9aaf30 R09: 0000000000050409
R10: ffff88808fd42a48 R11: ffff88808fd421c0 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000001
__might_fault mm/memory.c:4677 [inline]
__might_fault+0x137/0x1b0 mm/memory.c:4662
_copy_to_user+0x27/0xd0 lib/usercopy.c:25
copy_to_user include/linux/uaccess.h:155 [inline]
SYSC_newuname kernel/sys.c:1184 [inline]
SyS_newuname+0xf6/0x230 kernel/sys.c:1177
ieee80211 phy3: mac80211_hwsim_conf_tx (queue=2 txop=0 cw_min=15 cw_max=1023 aifs=2)
ieee80211 phy3: mac80211_hwsim_conf_tx (queue=3 txop=0 cw_min=15 cw_max=1023 aifs=2)
do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x46/0xbb
ieee80211 phy11: mac80211_hwsim_conf_tx (queue=0 txop=47 cw_min=3 cw_max=7 aifs=2)
RIP: 0033:0x7f9743046ec7
RSP: 002b:00007ffc604e7208 EFLAGS: 00000202 ORIG_RAX: 000000000000003f
ieee80211 phy11: mac80211_hwsim_conf_tx (queue=1 txop=94 cw_min=7 cw_max=15 aifs=2)
RAX: ffffffffffffffda RBX: 00007ffc604e7220 RCX: 00007f9743046ec7
RDX: 0000000000006000 RSI: 00007ffc604e74c8 RDI: 00007ffc604e7220
RBP: 00007ffc604e74c8 R08: 0000558f0957f670 R09: 0000000000000110
R10: 00000000000007d8 R11: 0000000000000202 R12: 0000000000000000
ieee80211 phy11: mac80211_hwsim_conf_tx (queue=2 txop=0 cw_min=15 cw_max=1023 aifs=3)
R13: 0000000000000000 R14: 0000000000000000 R15: 000000000000000f
Code: ea 03
ieee80211 phy3: mac80211_hwsim_bss_info_changed(changed=0x2000 vif->addr=02:00:00:00:03:00)
80 3c 02 00 0f 85 b5 0b 00 00 49
ieee80211 phy3: mac80211_hwsim_bss_info_changed(changed=0x8bfe vif->addr=02:00:00:00:03:00)
8b 9f 70 14 00 00 48 b8 00 00 00
ieee80211 phy11: mac80211_hwsim_conf_tx (queue=3 txop=0 cw_min=15 cw_max=1023 aifs=7)
00 00 fc ff df 48 8d bb d8 01 00
ieee80211 phy3: mac80211_hwsim_bss_info_changed: BSSID changed: 50:50:50:50:50:50
00 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 06 0f 8e 9c 0b 00 00 80 bb d8 01 00 00 00
RIP: ieee80211_multicast_to_unicast net/mac80211/tx.c:3680 [inline] RSP: ffff8880ba507528
RIP: ieee80211_subif_start_xmit+0x1f4/0xe00 net/mac80211/tx.c:3764 RSP: ffff8880ba507528
---[ end trace 9ed6f08c69e360ca ]---


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[syzbot]

syzbot suspects this issue was fixed by commit:

commit d882652c1c6fc339c5fb9535005f70ee79f11859
Author: Johannes Berg <johann...@intel.com>
Date: Fri Jan 22 16:11:16 2021 +0000

mac80211: pause TX while changing interface type

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=15753ea8d00000
start commit: 87335852 Linux 4.14.209
git tree: linux-4.14.y

kernel config: https://syzkaller.appspot.com/x/.config?x=77df3f7a7cfbd2e6
dashboard link: https://syzkaller.appspot.com/bug?extid=fcbcd11cca8dd50a7096

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1376baae500000

If the result looks correct, please mark the issue as fixed by replying with:

#syz fix: mac80211: pause TX while changing interface type

For information about bisection process see: https://goo.gl/tpsmEJ#bisection