------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 0 PID: 15125 at lib/refcount.c:25 refcount_warn_saturate+0xf3/0x1b0 lib/refcount.c:25
Modules linked in:
CPU: 0 PID: 15125 Comm: syz.2.2450 Not tainted 6.6.93-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:refcount_warn_saturate+0xf3/0x1b0 lib/refcount.c:25
Code: 15 0a 01 0f 85 98 00 00 00 e8 39 41 66 fd 5b 41 5e c3 e8 30 41 66 fd c6 05 e1 00 15 0a 01 48 c7 c7 40 0f fc 8a e8 0d a5 30 fd <0f> 0b eb e0 e8 14 41 66 fd c6 05 c6 00 15 0a 01 48 c7 c7 a0 0f fc
RSP: 0018:ffffc90000007848 EFLAGS: 00010246
RAX: 94671f7b46a93600 RBX: 0000000000000002 RCX: ffff888026b61e00
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000002
RBP: ffffc900000079d0 R08: ffffc90000007447 R09: 1ffff92000000e88
R10: dffffc0000000000 R11: fffff52000000e89 R12: ffff88807bed8000
R13: dffffc0000000000 R14: ffff88807bed8154 R15: ffff88801cf61c00
FS:  00007feed84e26c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c343cb3 CR3: 0000000026c0b000 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:261 [inline]
 tipc_aead_encrypt net/tipc/crypto.c:821 [inline]
 tipc_crypto_xmit+0x17cf/0x2250 net/tipc/crypto.c:1761
 tipc_bearer_xmit_skb+0x246/0x3f0 net/tipc/bearer.c:572
 tipc_disc_timeout+0x581/0x6d0 net/tipc/discover.c:338
 call_timer_fn+0x16e/0x530 kernel/time/timer.c:1700
 expire_timers kernel/time/timer.c:1751 [inline]
 __run_timers+0x52d/0x7d0 kernel/time/timer.c:2022
 run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2035
 handle_softirqs+0x280/0x820 kernel/softirq.c:578
 __do_softirq kernel/softirq.c:612 [inline]
 invoke_softirq kernel/softirq.c:452 [inline]
 __irq_exit_rcu+0xc7/0x190 kernel/softirq.c:661
 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
 sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:lock_acquire+0x1f2/0x410 kernel/locking/lockdep.c:5758
Code: 00 9c 8f 84 24 80 00 00 00 f6 84 24 81 00 00 00 02 0f 85 f5 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 04 3c 00 00 00 00 66 43 c7 44 3c 09 00 00 43 c6 44 3c 0b 00
RSP: 0018:ffffc9000453f680 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 94671f7b46a93600
RDX: 0000000000000000 RSI: ffffffff8aaac440 RDI: ffffffff8afc6780
RBP: ffffc9000453f788 R08: dffffc0000000000 R09: 1ffffffff21b08a4
R10: dffffc0000000000 R11: fffffbfff21b08a5 R12: 1ffff920008a7edc
R13: ffffffff8cd2f760 R14: 0000000000000246 R15: dffffc0000000000
 rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 rcu_read_lock include/linux/rcupdate.h:786 [inline]
 filemap_map_pages+0x178/0x1630 mm/filemap.c:3618
 do_fault_around mm/memory.c:4573 [inline]
 do_read_fault mm/memory.c:4606 [inline]
 do_fault mm/memory.c:4753 [inline]
 do_pte_missing mm/memory.c:3688 [inline]
 handle_pte_fault mm/memory.c:5025 [inline]
 __handle_mm_fault mm/memory.c:5166 [inline]
 handle_mm_fault+0x379b/0x4920 mm/memory.c:5331
 faultin_page mm/gup.c:868 [inline]
 __get_user_pages+0x5ea/0x1470 mm/gup.c:1167
 populate_vma_page_range+0x2b6/0x370 mm/gup.c:1593
 __mm_populate+0x24c/0x380 mm/gup.c:1696
 mm_populate include/linux/mm.h:3312 [inline]
 vm_mmap_pgoff+0x2e7/0x400 mm/util.c:561
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7feed758e929
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:00007feed84e2038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007feed77b5fa0 RCX: 00007feed758e929
RDX: b635773f06ebbeef RSI: 0000000000b36000 RDI: 0000200000000000
RBP: 00007feed7610b39 R08: ffffffffffffffff R09: 00000000ffffd000
R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007feed77b5fa0 R15: 00007ffe59c6fdd8
 </TASK>
----------------
Code disassembly (best guess):
   0:	00 9c 8f 84 24 80 00 	add    %bl,0x802484(%rdi,%rcx,4)
   7:	00 00                	add    %al,(%rax)
   9:	f6 84 24 81 00 00 00 	testb  $0x2,0x81(%rsp)
  10:	02
  11:	0f 85 f5 00 00 00    	jne    0x10c
  17:	41 f7 c6 00 02 00 00 	test   $0x200,%r14d
  1e:	74 01                	je     0x21
  20:	fb                   	sti
  21:	48 c7 44 24 60 0e 36 	movq   $0x45e0360e,0x60(%rsp)
  28:	e0 45
* 2a:	4b c7 04 3c 00 00 00 	movq   $0x0,(%r12,%r15,1) <-- trapping instruction
  31:	00
  32:	66 43 c7 44 3c 09 00 	movw   $0x0,0x9(%r12,%r15,1)
  39:	00
  3a:	43 c6 44 3c 0b 00    	movb   $0x0,0xb(%r12,%r15,1)