kernel BUG at ./include/linux/skbuff.h:LINE!

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 3ffe1e79 Linux 4.14.138
git tree: linux-4.14.y
console output: https://syzkaller.appspot.com/x/log.txt?x=16cfd59a600000
kernel config: https://syzkaller.appspot.com/x/.config?x=978e269523a888e8
dashboard link: https://syzkaller.appspot.com/bug?extid=0c2e9310a117c98192b8
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17cf52ee600000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+0c2e93...@syzkaller.appspotmail.com

IPv6: ADDRCONF(NETDEV_CHANGE): hsr0: link becomes ready
IPv6: ADDRCONF(NETDEV_UP): vxcan1: link is not ready
8021q: adding VLAN 0 to HW filter on device batadv0
IPv6: ADDRCONF(NETDEV_CHANGE): bond0: link becomes ready
------------[ cut here ]------------
kernel BUG at ./include/linux/skbuff.h:1406!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
Modules linked in:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.14.138 #34
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
task: ffffffff87676240 task.stack: ffffffff87600000
RIP: 0010:skb_queue_prev include/linux/skbuff.h:1406 [inline]
RIP: 0010:tcp_write_queue_prev include/net/tcp.h:1650 [inline]
RIP: 0010:tcp_write_queue_prev include/net/tcp.h:1647 [inline]
RIP: 0010:tcp_rtx_queue_tail include/net/tcp.h:1705 [inline]
RIP: 0010:tcp_fragment+0x12a7/0x13e0 net/ipv4/tcp_output.c:1284
RSP: 0018:ffff8880aee07c00 EFLAGS: 00010206
RAX: ffffffff87676240 RBX: ffff88809fc38d40 RCX: 1ffff110136e8599
RDX: 0000000000000100 RSI: ffff88809fc38d40 RDI: ffff88809fc38d48
RBP: ffff8880aee07c58 R08: 0000000001080020 R09: ffff88809fc38d68
R10: ffff88821fff8010 R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000001980 R14: ffff88809b742cd0 R15: 0000000001080020
FS: 0000000000000000(0000) GS:ffff8880aee00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000075c000 CR3: 0000000096e4d000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<IRQ>
tcp_write_wakeup+0x34c/0x5b0 net/ipv4/tcp_output.c:3708
tcp_send_probe0+0x4b/0x3fe net/ipv4/tcp_output.c:3736
tcp_probe_timer net/ipv4/tcp_timer.c:365 [inline]
tcp_write_timer_handler+0x6da/0x7e0 net/ipv4/tcp_timer.c:583
tcp_write_timer+0xd8/0x180 net/ipv4/tcp_timer.c:597
call_timer_fn+0x161/0x670 kernel/time/timer.c:1279
expire_timers kernel/time/timer.c:1318 [inline]
__run_timers kernel/time/timer.c:1634 [inline]
__run_timers kernel/time/timer.c:1602 [inline]
run_timer_softirq+0x5b4/0x1570 kernel/time/timer.c:1647
__do_softirq+0x244/0x9a0 kernel/softirq.c:288
invoke_softirq kernel/softirq.c:368 [inline]
irq_exit+0x160/0x1b0 kernel/softirq.c:409
exiting_irq arch/x86/include/asm/apic.h:648 [inline]
smp_apic_timer_interrupt+0x146/0x5e0 arch/x86/kernel/apic/apic.c:1064
apic_timer_interrupt+0x96/0xa0 arch/x86/entry/entry_64.S:792
</IRQ>
RIP: 0010:native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:61
RSP: 0018:ffffffff87607de8 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff10
RAX: 1ffffffff0ee2a5c RBX: ffffffff87676240 RCX: 0000000000000000
RDX: dffffc0000000000 RSI: 0000000000000001 RDI: ffffffff87676abc
RBP: ffffffff87607e10 R08: 1ffffffff104a501 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff877152d0
R13: 0000000000000000 R14: 0000000000000000 R15: ffffffff87676240
arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:557
default_idle_call+0x36/0x90 kernel/sched/idle.c:98
cpuidle_idle_call kernel/sched/idle.c:156 [inline]
do_idle+0x262/0x3d0 kernel/sched/idle.c:246
cpu_startup_entry+0x1b/0x20 kernel/sched/idle.c:351
rest_init+0x1d9/0x1e2 init/main.c:435
start_kernel+0x6df/0x6fd init/main.c:709
x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:381
x86_64_start_kernel+0x77/0x7b arch/x86/kernel/head64.c:362
secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:240
Code: 3c 02 00 0f 85 4f 01 00 00 48 8b 45 d0 ba 00 00 00 00 4c 8b b0 58 02
00 00 4c 3b 75 c0 4c 0f 44 f2 e9 e6 fc ff ff e8 b9 82 35 fc <0f> 0b e8 d2
2f 5f fc e9 31 fa ff ff 48 89 df e8 25 2f 5f fc e9
RIP: skb_queue_prev include/linux/skbuff.h:1406 [inline] RSP:
ffff8880aee07c00
RIP: tcp_write_queue_prev include/net/tcp.h:1650 [inline] RSP:
ffff8880aee07c00
RIP: tcp_write_queue_prev include/net/tcp.h:1647 [inline] RSP:
ffff8880aee07c00
RIP: tcp_rtx_queue_tail include/net/tcp.h:1705 [inline] RSP:
ffff8880aee07c00
RIP: tcp_fragment+0x12a7/0x13e0 net/ipv4/tcp_output.c:1284 RSP:
ffff8880aee07c00
---[ end trace 23df4925e79ca7e6 ]---


---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
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syzbot will keep track of this bug report. See:
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syzbot can test patches for this bug, for details see:
https://goo.gl/tpsmEJ#testing-patches

[syzbot]

syzbot has found a reproducer for the following crash on:

HEAD commit: 3ffe1e79 Linux 4.14.138
git tree: linux-4.14.y

console output: https://syzkaller.appspot.com/x/log.txt?x=171fb136600000

kernel config: https://syzkaller.appspot.com/x/.config?x=978e269523a888e8
dashboard link: https://syzkaller.appspot.com/bug?extid=0c2e9310a117c98192b8
compiler: gcc (GCC) 9.0.0 20181231 (experimental)

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10fadd8c600000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=10752a0e600000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+0c2e93...@syzkaller.appspotmail.com

IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_bond: link becomes ready
IPv6: ADDRCONF(NETDEV_UP): veth1: link is not ready
IPv6: ADDRCONF(NETDEV_UP): veth0_to_team: link is not ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth1: link becomes ready

------------[ cut here ]------------
kernel BUG at ./include/linux/skbuff.h:1406!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
Modules linked in:

CPU: 0 PID: 3153 Comm: kworker/0:2 Not tainted 4.14.138 #34

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011

Workqueue: events linkwatch_event
task: ffff88809bcae100 task.stack: ffff88809bc98000

RIP: 0010:skb_queue_prev include/linux/skbuff.h:1406 [inline]
RIP: 0010:tcp_write_queue_prev include/net/tcp.h:1650 [inline]
RIP: 0010:tcp_write_queue_prev include/net/tcp.h:1647 [inline]
RIP: 0010:tcp_rtx_queue_tail include/net/tcp.h:1705 [inline]
RIP: 0010:tcp_fragment+0x12a7/0x13e0 net/ipv4/tcp_output.c:1284
RSP: 0018:ffff8880aee07c00 EFLAGS: 00010206

RAX: ffff88809bcae100 RBX: ffff888098f7f000 RCX: 1ffff11014085049
RDX: 0000000000000100 RSI: ffff888098f7f000 RDI: ffff888098f7f008
RBP: ffff8880aee07c58 R08: 0000000001080020 R09: ffff888098f7f028

R10: ffff88821fff8010 R11: 0000000000000001 R12: 0000000000000000

R13: 0000000000006880 R14: ffff8880a0428250 R15: 0000000001080020

FS: 0000000000000000(0000) GS:ffff8880aee00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033

CR2: 00000000004b66a0 CR3: 000000007f08d000 CR4: 00000000001406f0

Call Trace:
<IRQ>
tcp_write_wakeup+0x34c/0x5b0 net/ipv4/tcp_output.c:3708
tcp_send_probe0+0x4b/0x3fe net/ipv4/tcp_output.c:3736
tcp_probe_timer net/ipv4/tcp_timer.c:365 [inline]
tcp_write_timer_handler+0x6da/0x7e0 net/ipv4/tcp_timer.c:583
tcp_write_timer+0xd8/0x180 net/ipv4/tcp_timer.c:597
call_timer_fn+0x161/0x670 kernel/time/timer.c:1279
expire_timers kernel/time/timer.c:1318 [inline]
__run_timers kernel/time/timer.c:1634 [inline]
__run_timers kernel/time/timer.c:1602 [inline]
run_timer_softirq+0x5b4/0x1570 kernel/time/timer.c:1647
__do_softirq+0x244/0x9a0 kernel/softirq.c:288
invoke_softirq kernel/softirq.c:368 [inline]
irq_exit+0x160/0x1b0 kernel/softirq.c:409
exiting_irq arch/x86/include/asm/apic.h:648 [inline]
smp_apic_timer_interrupt+0x146/0x5e0 arch/x86/kernel/apic/apic.c:1064
apic_timer_interrupt+0x96/0xa0 arch/x86/entry/entry_64.S:792
</IRQ>

RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:779
[inline]
RIP: 0010:console_unlock+0x9f8/0xed0 kernel/printk/printk.c:2399
RSP: 0018:ffff88809bc9f870 EFLAGS: 00000297 ORIG_RAX: ffffffffffffff10
RAX: ffff88809bcae100 RBX: 0000000000000200 RCX: 1ffff11013795d43
RDX: 0000000000000000 RSI: ffff88809bcae9f8 RDI: 0000000000000297
RBP: ffff88809bc9f900 R08: ffff88809bcae100 R09: ffff88809bcaea18
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: ffffffff83a6f130 R14: ffffffff87cea710 R15: dffffc0000000000
vprintk_emit kernel/printk/printk.c:1917 [inline]
vprintk_emit+0x1f9/0x600 kernel/printk/printk.c:1882
vprintk_default+0x28/0x30 kernel/printk/printk.c:1957
vprintk_func+0x5d/0x159 kernel/printk/printk_safe.c:401
printk+0x9e/0xbc kernel/printk/printk.c:1990
addrconf_notify.cold+0xfb/0x12f net/ipv6/addrconf.c:3442
notifier_call_chain+0x111/0x1b0 kernel/notifier.c:93
__raw_notifier_call_chain kernel/notifier.c:394 [inline]
raw_notifier_call_chain+0x2e/0x40 kernel/notifier.c:401
call_netdevice_notifiers_info+0x56/0x70 net/core/dev.c:1671
netdev_state_change net/core/dev.c:1318 [inline]
netdev_state_change+0xbf/0xe0 net/core/dev.c:1312
linkwatch_do_dev+0x8d/0xf0 net/core/link_watch.c:164
__linkwatch_run_queue+0x271/0x4b0 net/core/link_watch.c:202
linkwatch_event+0x40/0x60 net/core/link_watch.c:237
process_one_work+0x863/0x1600 kernel/workqueue.c:2114
worker_thread+0x5d9/0x1050 kernel/workqueue.c:2248
kthread+0x319/0x430 kernel/kthread.c:232
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404

Code: 3c 02 00 0f 85 4f 01 00 00 48 8b 45 d0 ba 00 00 00 00 4c 8b b0 58 02
00 00 4c 3b 75 c0 4c 0f 44 f2 e9 e6 fc ff ff e8 b9 82 35 fc <0f> 0b e8 d2
2f 5f fc e9 31 fa ff ff 48 89 df e8 25 2f 5f fc e9
RIP: skb_queue_prev include/linux/skbuff.h:1406 [inline] RSP:
ffff8880aee07c00
RIP: tcp_write_queue_prev include/net/tcp.h:1650 [inline] RSP:
ffff8880aee07c00
RIP: tcp_write_queue_prev include/net/tcp.h:1647 [inline] RSP:
ffff8880aee07c00
RIP: tcp_rtx_queue_tail include/net/tcp.h:1705 [inline] RSP:
ffff8880aee07c00
RIP: tcp_fragment+0x12a7/0x13e0 net/ipv4/tcp_output.c:1284 RSP:
ffff8880aee07c00

---[ end trace 56850354d186b296 ]---

[syzbot]

syzbot suspects this bug was fixed by commit:

commit e5df4baea324d3c21dc48f86ad24e5d9aed67c65
Author: Tim Froidcoeur <tim.fro...@tessares.net>
Date: Sat Aug 24 06:03:51 2019 +0000

tcp: fix tcp_rtx_queue_tail in case of empty retransmit queue

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1663fc32e00000
start commit: 3ffe1e79 Linux 4.14.138
git tree: linux-4.14.y

kernel config: https://syzkaller.appspot.com/x/.config?x=978e269523a888e8
dashboard link: https://syzkaller.appspot.com/bug?extid=0c2e9310a117c98192b8

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10fadd8c600000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=10752a0e600000

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

#syz fix: tcp: fix tcp_rtx_queue_tail in case of empty retransmit queue

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