------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: lib/refcount.c:28 at refcount_warn_saturate+0xf4/0x130 lib/refcount.c:28, CPU#3: syz.0.1764/12782
Modules linked in:
CPU: 3 UID: 0 PID: 12782 Comm: syz.0.1764 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:refcount_warn_saturate+0xf4/0x130 lib/refcount.c:28
Code: cc e8 70 f9 0e fd 48 8d 3d 59 b9 e8 0b 67 48 0f b9 3a e8 5f f9 0e fd 5b 5d e9 d8 93 94 06 e8 53 f9 0e fd 48 8d 3d 4c b9 e8 0b <67> 48 0f b9 3a e8 42 f9 0e fd 5b 5d c3 cc cc cc cc e8 36 f9 0e fd
RSP: 0018:ffffc900054ff120 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffff88803bf3ef00 RCX: ffffffff84f9b6bb
RDX: ffff88802cdc4a00 RSI: ffffffff84f9b74d RDI: ffffffff90e270a0
RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000004
R10: 0000000000000003 R11: 0000000000000000 R12: ffff88803bf3ef00
R13: ffffffff8a05bb60 R14: 0000000000000000 R15: 0000000000000018
FS: 00007f7276fc56c0(0000) GS:ffff8880d666a000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7276fc4ff8 CR3: 0000000039e81000 CR4: 0000000000352ef0
Call Trace:
<TASK>
__refcount_sub_and_test include/linux/refcount.h:400 [inline]
__refcount_dec_and_test include/linux/refcount.h:432 [inline]
refcount_dec_and_test include/linux/refcount.h:450 [inline]
sock_put include/net/sock.h:2009 [inline]
sk_common_release+0x260/0x370 net/core/sock.c:4024
inet_release+0xed/0x200 net/ipv4/af_inet.c:442
__sock_release net/socket.c:722 [inline]
sock_release+0x91/0x1c0 net/socket.c:750
rxe_release_udp_tunnel drivers/infiniband/sw/rxe/rxe_net.c:294 [inline]
rxe_sock_put+0xae/0x130 drivers/infiniband/sw/rxe/rxe_net.c:639
rxe_net_del+0x83/0x120 drivers/infiniband/sw/rxe/rxe_net.c:660
rxe_dellink+0x15/0x20 drivers/infiniband/sw/rxe/rxe.c:254
nldev_dellink+0x289/0x3c0 drivers/infiniband/core/nldev.c:1849
rdma_nl_rcv_msg+0x392/0x6f0 drivers/infiniband/core/netlink.c:195
rdma_nl_rcv_skb.constprop.0.isra.0+0x2cb/0x410 drivers/infiniband/core/netlink.c:239
netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
netlink_unicast+0x585/0x850 net/netlink/af_netlink.c:1344
netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1894
sock_sendmsg_nosec net/socket.c:787 [inline]
__sock_sendmsg net/socket.c:802 [inline]
____sys_sendmsg+0x9e1/0xb70 net/socket.c:2698
___sys_sendmsg+0x190/0x1e0 net/socket.c:2752
__sys_sendmsg+0x170/0x220 net/socket.c:2784
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f727619ce59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f7276fc5028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f7276416090 RCX: 00007f727619ce59
RDX: 0000000000000004 RSI: 0000200000004680 RDI: 0000000000000003
RBP: 00007f7276232d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7276416128 R14: 00007f7276416090 R15: 00007ffe765f7028
</TASK>
----------------
Code disassembly (best guess):
0: cc int3
1: e8 70 f9 0e fd call 0xfd0ef976
6: 48 8d 3d 59 b9 e8 0b lea 0xbe8b959(%rip),%rdi # 0xbe8b966
d: 67 48 0f b9 3a ud1 (%edx),%rdi
12: e8 5f f9 0e fd call 0xfd0ef976
17: 5b pop %rbx
18: 5d pop %rbp
19: e9 d8 93 94 06 jmp 0x69493f6
1e: e8 53 f9 0e fd call 0xfd0ef976
23: 48 8d 3d 4c b9 e8 0b lea 0xbe8b94c(%rip),%rdi # 0xbe8b976
* 2a: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction
2f: e8 42 f9 0e fd call 0xfd0ef976
34: 5b pop %rbx
35: 5d pop %rbp
36: c3 ret
37: cc int3
38: cc int3
39: cc int3
3a: cc int3
3b: e8 36 f9 0e fd call 0xfd0ef976