------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 1 PID: 6327 at lib/refcount.c:25 refcount_warn_saturate+0xff/0x1a0 lib/refcount.c:25
Modules linked in:
CPU: 1 PID: 6327 Comm: syz-executor Not tainted 5.15.185-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:refcount_warn_saturate+0xff/0x1a0 lib/refcount.c:25
Code: 09 01 48 c7 c7 40 6b 59 8a e8 dd 27 bb 05 0f 0b eb e0 e8 04 42 9c fd c6 05 ae 8f 79 09 01 48 c7 c7 80 6a 59 8a e8 c1 27 bb 05 <0f> 0b eb c4 e8 e8 41 9c fd c6 05 93 8f 79 09 01 48 c7 c7 e0 6a 59
RSP: 0018:ffffc90000dd0848 EFLAGS: 00010246
RAX: 529402d85ad45a00 RBX: 0000000000000002 RCX: ffff88807e0d8000
RDX: 0000000000000100 RSI: 0000000000000101 RDI: 0000000000000000
RBP: ffffc90000dd09b0 R08: dffffc0000000000 R09: ffffed1017224f24
R10: ffffed1017224f24 R11: 1ffff11017224f23 R12: ffff888075e9cf80
R13: dffffc0000000000 R14: 0000000000000002 R15: 0000000000000000
FS: 000055557b794500(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9dcf16df98 CR3: 000000006745f000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
__refcount_add include/linux/refcount.h:-1 [inline]
__refcount_inc include/linux/refcount.h:250 [inline]
refcount_inc include/linux/refcount.h:267 [inline]
get_net include/net/net_namespace.h:252 [inline]
tipc_aead_encrypt net/tipc/crypto.c:832 [inline]
tipc_crypto_xmit+0x1949/0x2560 net/tipc/crypto.c:1772
tipc_bearer_xmit_skb+0x228/0x3c0 net/tipc/bearer.c:574
tipc_disc_timeout+0x568/0x6b0 net/tipc/discover.c:338
call_timer_fn+0x16c/0x530 kernel/time/timer.c:1451
expire_timers kernel/time/timer.c:1496 [inline]
__run_timers+0x525/0x7c0 kernel/time/timer.c:1767
run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1780
handle_softirqs+0x328/0x820 kernel/softirq.c:576
__do_softirq kernel/softirq.c:610 [inline]
invoke_softirq kernel/softirq.c:450 [inline]
__irq_exit_rcu+0x12f/0x220 kernel/softirq.c:659
irq_exit_rcu+0x5/0x20 kernel/softirq.c:671
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:instrument_atomic_read include/linux/instrumented.h:71 [inline]
RIP: 0010:atomic_long_read include/linux/atomic/atomic-instrumented.h:1183 [inline]
RIP: 0010:__mutex_owner kernel/locking/mutex.c:78 [inline]
RIP: 0010:mutex_spin_on_owner+0x283/0x380 kernel/locking/mutex.c:352
Code: ef be 08 00 00 00 e8 bc 12 62 00 42 80 3c 3b 00 74 08 4c 89 ef e8 1d 11 62 00 49 f7 45 00 01 00 00 00 0f 85 8b 00 00 00 f3 90 <4c> 89 ef be 08 00 00 00 e8 90 12 62 00 42 80 3c 3b 00 0f 84 84 fe
RSP: 0018:ffffc9000331f470 EFLAGS: 00000246
RAX: ffff8880b9000000 RBX: 1ffffffff1a4551c RCX: ffffffff815b2808
RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000000
RBP: ffffffff8d22a930 R08: dffffc0000000000 R09: ffffed100fc1b001
R10: ffffed100fc1b001 R11: 1ffff1100fc1b000 R12: ffff88805611d940
R13: ffffffff8d22a8e0 R14: ffffffff8d22a930 R15: dffffc0000000000
mutex_optimistic_spin+0x38/0x300 kernel/locking/mutex.c:469
__mutex_lock_common+0xd18/0x2390 kernel/locking/mutex.c:680
__mutex_lock kernel/locking/mutex.c:729 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
rtnl_lock net/core/rtnetlink.c:72 [inline]
rtnetlink_rcv_msg+0x974/0xe60 net/core/rtnetlink.c:5647
netlink_rcv_skb+0x1e0/0x430 net/netlink/af_netlink.c:2489
netlink_unicast_kernel net/netlink/af_netlink.c:1311 [inline]
netlink_unicast+0x77c/0x920 net/netlink/af_netlink.c:1337
netlink_sendmsg+0x8ab/0xbc0 net/netlink/af_netlink.c:1905
sock_sendmsg_nosec net/socket.c:704 [inline]
__sock_sendmsg net/socket.c:716 [inline]
__sys_sendto+0x423/0x580 net/socket.c:2063
__do_sys_sendto net/socket.c:2075 [inline]
__se_sys_sendto net/socket.c:2071 [inline]
__x64_sys_sendto+0xda/0xf0 net/socket.c:2071
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f3c8671b7bc
Code: 2a 5f 02 00 44 8b 4c 24 2c 4c 8b 44 24 20 89 c5 44 8b 54 24 28 48 8b 54 24 18 b8 2c 00 00 00 48 8b 74 24 10 8b 7c 24 08 0f 05 <48> 3d 00 f0 ff ff 77 34 89 ef 48 89 44 24 08 e8 70 5f 02 00 48 8b
RSP: 002b:00007ffe41614210 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f3c8746f620 RCX: 00007f3c8671b7bc
RDX: 000000000000002c RSI: 00007f3c8746f670 RDI: 0000000000000003
RBP: 0000000000000000 R08: 00007ffe41614264 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003
R13: 0000000000000000 R14: 00007f3c8746f670 R15: 0000000000000000
----------------
Code disassembly (best guess):
0: ef out %eax,(%dx)
1: be 08 00 00 00 mov $0x8,%esi
6: e8 bc 12 62 00 call 0x6212c7
b: 42 80 3c 3b 00 cmpb $0x0,(%rbx,%r15,1)
10: 74 08 je 0x1a
12: 4c 89 ef mov %r13,%rdi
15: e8 1d 11 62 00 call 0x621137
1a: 49 f7 45 00 01 00 00 testq $0x1,0x0(%r13)
21: 00
22: 0f 85 8b 00 00 00 jne 0xb3
28: f3 90 pause
* 2a: 4c 89 ef mov %r13,%rdi <-- trapping instruction
2d: be 08 00 00 00 mov $0x8,%esi
32: e8 90 12 62 00 call 0x6212c7
37: 42 80 3c 3b 00 cmpb $0x0,(%rbx,%r15,1)
3c: 0f .byte 0xf
3d: 84 .byte 0x84
3e: 84 fe test %bh,%dh