------------[ cut here ]------------ refcount_t: addition on 0; use-after-free. WARNING: CPU: 0 PID: 28120 at lib/refcount.c:25 refcount_warn_saturate+0xff/0x1a0 lib/refcount.c:25 Modules linked in: CPU: 0 PID: 28120 Comm: modprobe Not tainted 6.1.141-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 a0 d2 be 8a e8 ad 30 45 fd 0f 0b eb e0 e8 f4 1d 79 fd c6 05 fa 72 e2 09 01 48 c7 c7 e0 d1 be 8a e8 91 30 45 fd <0f> 0b eb c4 e8 d8 1d 79 fd c6 05 df 72 e2 09 01 48 c7 c7 40 d2 be RSP: 0018:ffffc90000007688 EFLAGS: 00010246 RAX: 0eb067906ed62100 RBX: 0000000000000002 RCX: ffff88805bef9dc0 RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000002 RBP: ffffc900000077e8 R08: dffffc0000000000 R09: fffff52000000e61 R10: fffff52000000e61 R11: 1ffff92000000e60 R12: ffff888058eb1c40 R13: dffffc0000000000 R14: 0000000000000002 R15: ffff888054387048 FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb8743bfb4c CR3: 000000005b0d5000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 3a810b1eb6134bdc 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:257 [inline] tipc_aead_encrypt net/tipc/crypto.c:821 [inline] tipc_crypto_xmit+0x17a9/0x2300 net/tipc/crypto.c:1761 tipc_crypto_clone_msg+0x91/0x160 net/tipc/crypto.c:1656 tipc_crypto_xmit+0x1928/0x2300 net/tipc/crypto.c:1717 tipc_bearer_xmit_skb+0x242/0x3f0 net/tipc/bearer.c:574 tipc_disc_timeout+0x568/0x6b0 net/tipc/discover.c:338 call_timer_fn+0x1a0/0x670 kernel/time/timer.c:1504 expire_timers kernel/time/timer.c:1549 [inline] __run_timers+0x525/0x7c0 kernel/time/timer.c:1820 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1833 handle_softirqs+0x2a1/0x920 kernel/softirq.c:596 __do_softirq kernel/softirq.c:630 [inline] invoke_softirq kernel/softirq.c:470 [inline] __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:679 irq_exit_rcu+0x5/0x20 kernel/softirq.c:691 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline] sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1118 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:lock_acquire+0x20f/0x490 kernel/locking/lockdep.c:5666 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 44 3d 00 00 00 00 00 66 43 c7 44 3d 09 00 00 43 c6 44 3d 0b RSP: 0018:ffffc90003c07140 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0eb067906ed62100 RDX: 0000000000000000 RSI: ffffffff8a6c1160 RDI: ffffffff8abf1360 RBP: ffffc90003c07248 R08: dffffc0000000000 R09: fffffbfff2117049 R10: fffffbfff2117049 R11: 1ffffffff2117048 R12: 0000000000000000 R13: 1ffff92000780e34 R14: 0000000000000246 R15: dffffc0000000000 rcu_lock_acquire include/linux/rcupdate.h:350 [inline] rcu_read_lock include/linux/rcupdate.h:791 [inline] page_ext_get+0x3a/0x2a0 mm/page_ext.c:157 __set_page_owner+0x24/0x60 mm/page_owner.c:192 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2532 prep_new_page mm/page_alloc.c:2539 [inline] get_page_from_freelist+0x1a26/0x1ac0 mm/page_alloc.c:4328 __alloc_pages+0x1df/0x4e0 mm/page_alloc.c:5614 __pte_alloc_one include/asm-generic/pgalloc.h:63 [inline] pte_alloc_one+0x80/0x2f0 arch/x86/mm/pgtable.c:33 __do_fault+0xd7/0x4e0 mm/memory.c:4275 do_cow_fault mm/memory.c:4661 [inline] do_fault mm/memory.c:4762 [inline] handle_pte_fault mm/memory.c:5031 [inline] __handle_mm_fault mm/memory.c:5173 [inline] handle_mm_fault+0x23b6/0x3e70 mm/memory.c:5294 do_user_addr_fault+0x51f/0xb10 arch/x86/mm/fault.c:1340 handle_page_fault arch/x86/mm/fault.c:1431 [inline] exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1487 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608 RIP: 0010:clear_user_erms+0xa/0x10 arch/x86/lib/clear_page_64.S:182 Code: 74 03 f3 48 ab 83 e2 07 74 04 89 d1 f3 aa 31 c0 c3 48 c1 e1 03 83 e2 07 48 01 d1 eb f1 90 90 90 48 83 f9 40 0f 82 76 ff ff ff aa 31 c0 c3 00 55 41 57 41 56 41 55 41 54 53 48 83 ec 20 48 89 RSP: 0018:ffffc90003c07a18 EFLAGS: 00050206 RAX: 0000000000000000 RBX: 00000000000004b4 RCX: 00000000000004b4 RDX: 0000000000000000 RSI: ffffffff8a6c1160 RDI: 00007fb8743bfb4c RBP: 00007fb8743bfb4c R08: dffffc0000000000 R09: fffffbfff1bfd0b6 R10: fffffbfff1bfd0b6 R11: 1ffffffff1bfd0b5 R12: ffff88807643f800 R13: dffffc0000000000 R14: 0000000000000b4c R15: 0000000000000003 __clear_user arch/x86/include/asm/uaccess_64.h:103 [inline] clear_user arch/x86/include/asm/uaccess_64.h:124 [inline] padzero fs/binfmt_elf.c:124 [inline] load_elf_interp+0xbe1/0xd40 fs/binfmt_elf.c:716 load_elf_binary+0x19cd/0x26d0 fs/binfmt_elf.c:1272 search_binary_handler fs/exec.c:1764 [inline] exec_binprm fs/exec.c:1805 [inline] bprm_execve+0xb10/0x18a0 fs/exec.c:1874 kernel_execve+0x8b9/0x9c0 fs/exec.c:2039 call_usermodehelper_exec_async+0x207/0x350 kernel/umh.c:113 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 ---------------- 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 44 3d 00 00 00 movq $0x0,0x0(%r13,%r15,1) <-- trapping instruction 31: 00 00 33: 66 43 c7 44 3d 09 00 movw $0x0,0x9(%r13,%r15,1) 3a: 00 3b: 43 rex.XB 3c: c6 .byte 0xc6 3d: 44 rex.R 3e: 3d .byte 0x3d 3f: 0b .byte 0xb