------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 0 PID: 8544 at lib/refcount.c:25 refcount_warn_saturate+0xff/0x1a0 lib/refcount.c:25
Modules linked in:
CPU: 0 PID: 8544 Comm: syz.2.1407 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:ffffc900000076a8 EFLAGS: 00010246
RAX: edfae4224ed7d700 RBX: 0000000000000002 RCX: ffff88802a0ed940
RDX: 0000000000000100 RSI: 0000000080000101 RDI: 0000000000000000
RBP: ffffc90000007808 R08: dffffc0000000000 R09: fffff52000000e39
R10: fffff52000000e39 R11: 1ffff92000000e38 R12: ffff88801ab9cf80
R13: dffffc0000000000 R14: 0000000000000002 R15: 0000000000000000
FS:  00007f66820266c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbf48020000 CR3: 0000000070deb000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 __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_crypto_clone_msg+0x91/0x160 net/tipc/crypto.c:1667
 tipc_crypto_xmit+0x1ac5/0x2560 net/tipc/crypto.c:1728
 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
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:__sanitizer_cov_trace_pc+0x41/0x60 kernel/kcov.c:211
Code: ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 34 16 00 00 00 74 2c 8b 91 10 16 00 00 83 fa 02 75 21 48 8b 91 18 16 00 00 48 8b 32 <48> 8d 7e 01 8b 89 14 16 00 00 48 39 cf 73 08 48 89 44 f2 08 48 89
RSP: 0018:ffffc9000304f930 EFLAGS: 00000246
RAX: ffffffff81ab5b4d RBX: ffffea00015dd540 RCX: ffff88802a0ed940
RDX: ffffc900056b9000 RSI: 000000000007ffff RDI: 0000000000040004
RBP: 0000000000001052 R08: 0000000000000004 R09: 0000000000000003
R10: fffff52000609f1c R11: 1ffff92000609f1c R12: 000ffffffffff000
R13: 1ffff1100445fc8e R14: 0000000000000000 R15: 0000000057755027
 try_grab_page+0x3d/0x460 mm/gup.c:211
 follow_page_pte+0x784/0xc20 mm/gup.c:584
 follow_pmd_mask mm/gup.c:-1 [inline]
 follow_pud_mask mm/gup.c:788 [inline]
 follow_p4d_mask mm/gup.c:814 [inline]
 follow_page_mask+0xa6e/0x12d0 mm/gup.c:873
 __get_user_pages+0xdb5/0x11c0 mm/gup.c:1195
 populate_vma_page_range+0x213/0x290 mm/gup.c:1529
 __mm_populate+0x26f/0x3a0 mm/gup.c:1638
 mm_populate include/linux/mm.h:2632 [inline]
 vm_mmap_pgoff+0x203/0x2b0 mm/util.c:556
 ksys_mmap_pgoff+0x140/0x780 mm/mmap.c:1623
 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: 0033:0x7f66841be929
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f6682026038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007f66843e5fa0 RCX: 00007f66841be929
RDX: b635773f06ebbeee RSI: 0000000000b36000 RDI: 0000200000000000
RBP: 00007f6684240b39 R08: ffffffffffffffff R09: 0000000000000000
R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f66843e5fa0 R15: 00007ffdbf13d438
 </TASK>
----------------
Code disassembly (best guess):
   0:	ff 00                	incl   (%rax)
   2:	74 11                	je     0x15
   4:	81 fa 00 01 00 00    	cmp    $0x100,%edx
   a:	75 35                	jne    0x41
   c:	83 b9 34 16 00 00 00 	cmpl   $0x0,0x1634(%rcx)
  13:	74 2c                	je     0x41
  15:	8b 91 10 16 00 00    	mov    0x1610(%rcx),%edx
  1b:	83 fa 02             	cmp    $0x2,%edx
  1e:	75 21                	jne    0x41
  20:	48 8b 91 18 16 00 00 	mov    0x1618(%rcx),%rdx
  27:	48 8b 32             	mov    (%rdx),%rsi
* 2a:	48 8d 7e 01          	lea    0x1(%rsi),%rdi <-- trapping instruction
  2e:	8b 89 14 16 00 00    	mov    0x1614(%rcx),%ecx
  34:	48 39 cf             	cmp    %rcx,%rdi
  37:	73 08                	jae    0x41
  39:	48 89 44 f2 08       	mov    %rax,0x8(%rdx,%rsi,8)
  3e:	48                   	rex.W
  3f:	89                   	.byte 0x89