WARNING in tcp_send_loss_probe

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: f02af7b0 Merge 4.14.143 into android-4.14
git tree: android-4.14
console output: https://syzkaller.appspot.com/x/log.txt?x=118232a5600000
kernel config: https://syzkaller.appspot.com/x/.config?x=4d9cf2fd50fd7015
dashboard link: https://syzkaller.appspot.com/bug?extid=6eb3415bba75206543e8
compiler: gcc (GCC) 9.0.0 20181231 (experimental)

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+6eb341...@syzkaller.appspotmail.com

invalid inflight: 1 state 4 cwnd 10 mss 1448
------------[ cut here ]------------
WARNING: CPU: 1 PID: 0 at net/ipv4/tcp_output.c:2507
tcp_send_loss_probe.cold+0x7e/0x94 net/ipv4/tcp_output.c:2507
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.14.143+ #0
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0xca/0x134 lib/dump_stack.c:53
panic+0x1ea/0x3d3 kernel/panic.c:182
__warn.cold+0x2f/0x3a kernel/panic.c:546
report_bug+0x20a/0x248 lib/bug.c:186
fixup_bug arch/x86/kernel/traps.c:177 [inline]
fixup_bug arch/x86/kernel/traps.c:172 [inline]
do_error_trap+0x1bf/0x2d0 arch/x86/kernel/traps.c:295
invalid_op+0x18/0x40 arch/x86/entry/entry_64.S:963
RIP: 0010:tcp_send_loss_probe.cold+0x7e/0x94 net/ipv4/tcp_output.c:2507
RSP: 0018:ffff8881dbb07ca8 EFLAGS: 00010286
RAX: 000000000000002c RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff91669f80 RDI: ffffed103b760f87
RBP: ffff8881d3945e80 R08: 000000000000002c R09: ffffed103b764ce9
R10: ffffed103b764ce8 R11: ffff8881dbb26747 R12: 00000000000005a8
R13: 0000000000000001 R14: 000000000000000a R15: ffff8881d3945e80
tcp_write_timer_handler+0x46b/0x780 net/ipv4/tcp_timer.c:575
tcp_write_timer+0xc9/0x170 net/ipv4/tcp_timer.c:597
call_timer_fn+0x15b/0x6a0 kernel/time/timer.c:1279
expire_timers+0x227/0x4c0 kernel/time/timer.c:1318
__run_timers kernel/time/timer.c:1634 [inline]
run_timer_softirq+0x1eb/0x5d0 kernel/time/timer.c:1647
__do_softirq+0x234/0x9ec kernel/softirq.c:288
invoke_softirq kernel/softirq.c:368 [inline]
irq_exit+0x114/0x150 kernel/softirq.c:409
exiting_irq arch/x86/include/asm/apic.h:648 [inline]
smp_apic_timer_interrupt+0x1a7/0x650 arch/x86/kernel/apic/apic.c:1102
apic_timer_interrupt+0x8c/0xa0 arch/x86/entry/entry_64.S:792
</IRQ>
RIP: 0010:native_safe_halt+0x13/0x20 arch/x86/include/asm/irqflags.h:61
RSP: 0018:ffff8881daa8fd60 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff10
RAX: 0000000000000000 RBX: ffffffff9202eba8 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff8881daa7372c
RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: ffff8881daa72f00 R15: dffffc0000000000
arch_safe_halt arch/x86/include/asm/paravirt.h:94 [inline]
default_idle+0x61/0x3b0 arch/x86/kernel/process.c:566
cpuidle_idle_call kernel/sched/idle.c:159 [inline]
do_idle+0x2e6/0x390 kernel/sched/idle.c:268
cpu_startup_entry+0xc6/0xd0 kernel/sched/idle.c:374
start_secondary+0x3a8/0x4b0 arch/x86/kernel/smpboot.c:272
secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:240
Kernel Offset: 0xe800000 from 0xffffffff81000000 (relocation range:
0xffffffff80000000-0xffffffffbfffffff)
Rebooting in 86400 seconds..


---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

[syzbot]

syzbot has found a reproducer for the following crash on:

HEAD commit: f02af7b0 Merge 4.14.143 into android-4.14
git tree: android-4.14

console output: https://syzkaller.appspot.com/x/log.txt?x=135dfc69600000

kernel config: https://syzkaller.appspot.com/x/.config?x=4d9cf2fd50fd7015
dashboard link: https://syzkaller.appspot.com/bug?extid=6eb3415bba75206543e8
compiler: gcc (GCC) 9.0.0 20181231 (experimental)

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1255ade6600000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1417256e600000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+6eb341...@syzkaller.appspotmail.com

invalid inflight: 1 state 4 cwnd 10 mss 21888
------------[ cut here ]------------
WARNING: CPU: 0 PID: 1997 at net/ipv4/tcp_output.c:2507

tcp_send_loss_probe.cold+0x7e/0x94 net/ipv4/tcp_output.c:2507
Kernel panic - not syncing: panic_on_warn set ...

CPU: 0 PID: 1997 Comm: syz-executor380 Not tainted 4.14.143+ #0

Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0xca/0x134 lib/dump_stack.c:53
panic+0x1ea/0x3d3 kernel/panic.c:182
__warn.cold+0x2f/0x3a kernel/panic.c:546
report_bug+0x20a/0x248 lib/bug.c:186
fixup_bug arch/x86/kernel/traps.c:177 [inline]
fixup_bug arch/x86/kernel/traps.c:172 [inline]
do_error_trap+0x1bf/0x2d0 arch/x86/kernel/traps.c:295
invalid_op+0x18/0x40 arch/x86/entry/entry_64.S:963
RIP: 0010:tcp_send_loss_probe.cold+0x7e/0x94 net/ipv4/tcp_output.c:2507

RSP: 0018:ffff8881dba07ca8 EFLAGS: 00010286
RAX: 000000000000002d RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff83469f80 RDI: ffffed103b740f87
RBP: ffff8881d45b9500 R08: 000000000000002d R09: ffffed103b744ce9
R10: ffffed103b744ce8 R11: ffff8881dba26747 R12: 0000000000005580
R13: 0000000000000001 R14: 000000000000000a R15: ffff8881d45b9500

tcp_write_timer_handler+0x46b/0x780 net/ipv4/tcp_timer.c:575
tcp_write_timer+0xc9/0x170 net/ipv4/tcp_timer.c:597
call_timer_fn+0x15b/0x6a0 kernel/time/timer.c:1279
expire_timers+0x227/0x4c0 kernel/time/timer.c:1318
__run_timers kernel/time/timer.c:1634 [inline]
run_timer_softirq+0x1eb/0x5d0 kernel/time/timer.c:1647
__do_softirq+0x234/0x9ec kernel/softirq.c:288
invoke_softirq kernel/softirq.c:368 [inline]
irq_exit+0x114/0x150 kernel/softirq.c:409
exiting_irq arch/x86/include/asm/apic.h:648 [inline]
smp_apic_timer_interrupt+0x1a7/0x650 arch/x86/kernel/apic/apic.c:1102
apic_timer_interrupt+0x8c/0xa0 arch/x86/entry/entry_64.S:792
</IRQ>

RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:46 [inline]
RIP: 0010:stack_access_ok+0x2f/0x130 arch/x86/kernel/unwind_orc.c:279
RSP: 0018:ffff8881d15873f0 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff10
RAX: 0000000000000000 RBX: 1ffff1103a2b0e83 RCX: 1ffff1103a2b0eae
RDX: 0000000000000008 RSI: ffff8881d1587898 RDI: ffff8881d1587570
RBP: ffff8881d1587898 R08: 0000000000000001 R09: ffff8881d1587870
R10: ffff8881d15875a5 R11: 000000000001c033 R12: ffff8881d1587570
R13: dffffc0000000000 R14: ffff8881d15878c8 R15: 0000000000000001
deref_stack_reg+0x66/0xe0 arch/x86/kernel/unwind_orc.c:289
unwind_next_frame+0xe07/0x1810 arch/x86/kernel/unwind_orc.c:474
__save_stack_trace+0x7a/0xf0 arch/x86/kernel/stacktrace.c:44
save_stack mm/kasan/common.c:76 [inline]
set_track mm/kasan/common.c:85 [inline]
__kasan_slab_free+0x164/0x210 mm/kasan/common.c:457
slab_free_hook mm/slub.c:1407 [inline]
slab_free_freelist_hook mm/slub.c:1458 [inline]
slab_free mm/slub.c:3039 [inline]
kmem_cache_free+0xd7/0x3b0 mm/slub.c:3055
anon_vma_chain_free mm/rmap.c:134 [inline]
unlink_anon_vmas+0x284/0x7e0 mm/rmap.c:401
free_pgtables+0xab/0x1c0 mm/memory.c:643
exit_mmap+0x222/0x440 mm/mmap.c:3073
__mmput kernel/fork.c:940 [inline]
mmput+0xeb/0x370 kernel/fork.c:961
exit_mm kernel/exit.c:545 [inline]
do_exit+0x905/0x2a20 kernel/exit.c:862
do_group_exit+0x100/0x2e0 kernel/exit.c:978
get_signal+0x39f/0x1cc0 kernel/signal.c:2422
do_signal+0x96/0x15d0 arch/x86/kernel/signal.c:814
exit_to_usermode_loop+0x11d/0x160 arch/x86/entry/common.c:160
prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline]
syscall_return_slowpath arch/x86/entry/common.c:270 [inline]
do_syscall_64+0x3a3/0x520 arch/x86/entry/common.c:297
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x442579
RSP: 002b:00007ffdb12d79e8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffe0 RBX: 0000000000000003 RCX: 0000000000442579
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 0000000000005fa4 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffdb12d7a50
R13: 00000000004034d0 R14: 0000000000000000 R15: 0000000000000000
Kernel Offset: 0x600000 from 0xffffffff81000000 (relocation range: