WARNING: refcount bug in sctp_transport_put (3)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 2c87f7a3 Merge tag 'pwm/for-5.12-rc1' of git://git.kernel...
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=155a6632d00000
kernel config: https://syzkaller.appspot.com/x/.config?x=eb762f1df8da5074
dashboard link: https://syzkaller.appspot.com/bug?extid=9cf577014b7a043dbb0d
userspace arch: i386

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

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9cf577...@syzkaller.appspotmail.com

WARNING: CPU: 1 PID: 10072 at lib/refcount.c:28 refcount_warn_saturate+0x1d1/0x1e0 lib/refcount.c:28
Modules linked in:
CPU: 1 PID: 10072 Comm: syz-executor.0 Not tainted 5.11.0-syzkaller #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014
RIP: 0010:refcount_warn_saturate+0x1d1/0x1e0 lib/refcount.c:28
Code: e9 db fe ff ff 48 89 df e8 dc 17 f5 fd e9 8a fe ff ff e8 22 3a b1 fd 48 c7 c7 a0 d8 be 89 c6 05 60 9d ef 09 01 e8 a0 f1 fe 04 <0f> 0b e9 af fe ff ff 0f 1f 84 00 00 00 00 00 41 56 41 55 41 54 55
RSP: 0018:ffffc900004e8d08 EFLAGS: 00010286
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff8880137ad340 RSI: ffffffff815bd0e5 RDI: fffff5200009d193
RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff815b61be R11: 0000000000000000 R12: ffff88805f193020
R13: 1ffff9200009d1a9 R14: ffffffff882930c0 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff88802cb00000(0000) knlGS:0000000000000000
CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 0000000008169834 CR3: 000000000bc8e000 CR4: 0000000000150ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<IRQ>
__refcount_sub_and_test include/linux/refcount.h:283 [inline]
__refcount_dec_and_test include/linux/refcount.h:315 [inline]
refcount_dec_and_test include/linux/refcount.h:333 [inline]
sctp_transport_put+0x138/0x180 net/sctp/transport.c:325
call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1431
expire_timers kernel/time/timer.c:1476 [inline]
__run_timers.part.0+0x67c/0xa50 kernel/time/timer.c:1745
__run_timers kernel/time/timer.c:1726 [inline]
run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1758
__do_softirq+0x29b/0x9f6 kernel/softirq.c:345
invoke_softirq kernel/softirq.c:221 [inline]
__irq_exit_rcu kernel/softirq.c:422 [inline]
irq_exit_rcu+0x134/0x200 kernel/softirq.c:434
sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1100
</IRQ>
asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:632
RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline]
RIP: 0010:lockdep_enabled kernel/locking/lockdep.c:90 [inline]
RIP: 0010:lock_is_held_type+0x31/0x130 kernel/locking/lockdep.c:5542
Code: bd 01 00 00 00 41 54 55 53 48 83 ec 08 8b 0d 32 af c3 04 85 c9 0f 84 d0 00 00 00 65 8b 05 d7 8f ff 76 85 c0 0f 85 c1 00 00 00 <65> 4c 8b 24 25 00 f0 01 00 41 8b 94 24 84 09 00 00 85 d2 0f 85 a8
RSP: 0018:ffffc90023f5f568 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 1ffff920047ebeb9 RCX: 0000000000000001
RDX: 1ffffffff17ef936 RSI: 00000000ffffffff RDI: ffffffff8bf742e0
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8dc5e84f
R10: fffffbfff1b8bd09 R11: 0000000000000000 R12: 0000000000000001
R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000000
lock_is_held include/linux/lockdep.h:278 [inline]
rcu_read_lock_sched_held+0x3a/0x70 kernel/rcu/update.c:125
trace_lock_acquire include/trace/events/lock.h:13 [inline]
lock_acquire+0x5d4/0x730 kernel/locking/lockdep.c:5481
rcu_lock_acquire include/linux/rcupdate.h:267 [inline]
rcu_read_lock include/linux/rcupdate.h:656 [inline]
lock_page_memcg+0x69/0x4f0 mm/memcontrol.c:2142
page_remove_rmap+0x25/0x1430 mm/rmap.c:1349
zap_pte_range mm/memory.c:1276 [inline]
zap_pmd_range mm/memory.c:1380 [inline]
zap_pud_range mm/memory.c:1409 [inline]
zap_p4d_range mm/memory.c:1430 [inline]
unmap_page_range+0xe30/0x2650 mm/memory.c:1451
unmap_single_vma+0x198/0x300 mm/memory.c:1496
unmap_vmas+0x16d/0x2f0 mm/memory.c:1528
exit_mmap+0x2a8/0x590 mm/mmap.c:3218
__mmput+0x122/0x470 kernel/fork.c:1082
mmput+0x58/0x60 kernel/fork.c:1103
exit_mm kernel/exit.c:501 [inline]
do_exit+0xb6f/0x2ae0 kernel/exit.c:812
do_group_exit+0x125/0x310 kernel/exit.c:922
get_signal+0x42c/0x2100 kernel/signal.c:2773
arch_do_signal_or_restart+0x2a8/0x1eb0 arch/x86/kernel/signal.c:811
handle_signal_work kernel/entry/common.c:147 [inline]
exit_to_user_mode_loop kernel/entry/common.c:171 [inline]
exit_to_user_mode_prepare+0x148/0x250 kernel/entry/common.c:208
__syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline]
syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:301
__do_fast_syscall_32+0x62/0x80 arch/x86/entry/common.c:142
do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:164
entry_SYSENTER_compat_after_hwframe+0x4d/0x5c
RIP: 0023:0xf7fd8549
Code: Unable to access opcode bytes at RIP 0xf7fd851f.
RSP: 002b:00000000f55d25fc EFLAGS: 00000296 ORIG_RAX: 0000000000000150
RAX: 0000000000000003 RBX: 000000002001d000 RCX: 0000000000000000
RDX: 00000000ffffffff RSI: 00000000ffffffff RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.