------------[ cut here ]------------ refcount_t: addition on 0; use-after-free. WARNING: CPU: 1 PID: 10617 at lib/refcount.c:25 refcount_warn_saturate+0xfa/0x1d0 lib/refcount.c:25 Modules linked in: CPU: 1 UID: 0 PID: 10617 Comm: syz.2.1651 Not tainted 6.15.0-syzkaller-12331-gcfc4ca8986bb #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:refcount_warn_saturate+0xfa/0x1d0 lib/refcount.c:25 Code: 00 00 e8 09 2d ff fc 5b 41 5e e9 3c 12 4f fc cc e8 fb 2c ff fc c6 05 e3 ca c9 0a 01 90 48 c7 c7 c0 38 e2 8b e8 17 db c2 fc 90 <0f> 0b 90 90 eb d7 e8 db 2c ff fc c6 05 c4 ca c9 0a 01 90 48 c7 c7 RSP: 0018:ffffc90000a08828 EFLAGS: 00010246 RAX: 69147da89d9ac800 RBX: 0000000000000002 RCX: ffff88802bba1e00 RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000002 RBP: ffffc90000a089b0 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffffbfff1bfaa44 R12: ffff888077b18000 R13: dffffc0000000000 R14: ffff888077b1816c R15: ffff88802fe7b000 FS: 00007fec216cc6c0(0000) GS:ffff888125d55000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000562a32673168 CR3: 00000000328c6000 CR4: 0000000000350ef0 Call Trace: __refcount_add include/linux/refcount.h:-1 [inline] __refcount_inc include/linux/refcount.h:366 [inline] refcount_inc include/linux/refcount.h:383 [inline] get_net include/net/net_namespace.h:268 [inline] tipc_aead_encrypt net/tipc/crypto.c:821 [inline] tipc_crypto_xmit+0x1820/0x22c0 net/tipc/crypto.c:1761 tipc_bearer_xmit_skb+0x245/0x400 net/tipc/bearer.c:572 tipc_disc_timeout+0x580/0x6d0 net/tipc/discover.c:338 call_timer_fn+0x17e/0x5f0 kernel/time/timer.c:1747 expire_timers kernel/time/timer.c:1798 [inline] __run_timers kernel/time/timer.c:2372 [inline] __run_timer_base+0x61a/0x860 kernel/time/timer.c:2384 run_timer_base kernel/time/timer.c:2393 [inline] run_timer_softirq+0xb7/0x180 kernel/time/timer.c:2403 handle_softirqs+0x286/0x870 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:87 [inline] RIP: 0010:memory_is_nonzero mm/kasan/generic.c:104 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:129 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:161 [inline] RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline] RIP: 0010:kasan_check_range+0x9f/0x2c0 mm/kasan/generic.c:189 Code: 00 fc ff df 4d 8d 34 19 4d 89 f4 4d 29 dc 49 83 fc 10 7f 29 4d 85 e4 0f 84 41 01 00 00 4c 89 cb 48 f7 d3 4c 01 fb 41 80 3b 00 <0f> 85 de 01 00 00 49 ff c3 48 ff c3 75 ee e9 21 01 00 00 44 89 dd RSP: 0018:ffffc900045af548 EFLAGS: 00000246 RAX: ffffffff823f7a01 RBX: fffffffffffffffe RCX: ffffffff823f7a5d RDX: 0000000000000001 RSI: 0000000000000018 RDI: ffffc900045af620 RBP: 0000000000000000 R08: ffffc900045af637 R09: 1ffff920008b5ec6 R10: dffffc0000000000 R11: fffff520008b5ec5 R12: 0000000000000003 R13: 000000000000d7a4 R14: fffff520008b5ec7 R15: 1ffff920008b5ec4 __asan_memset+0x22/0x50 mm/kasan/shadow.c:84 seq_printf+0xad/0x270 fs/seq_file.c:403 __io_uring_show_fdinfo io_uring/fdinfo.c:139 [inline] io_uring_show_fdinfo+0xa63/0x1560 io_uring/fdinfo.c:224 seq_show+0x5e6/0x750 fs/proc/fd.c:68 traverse+0x1e9/0x570 fs/seq_file.c:111 seq_read_iter+0xcfe/0xe10 fs/seq_file.c:195 seq_read+0x2e2/0x3d0 fs/seq_file.c:162 do_loop_readv_writev fs/read_write.c:847 [inline] vfs_readv+0x5aa/0x850 fs/read_write.c:1020 do_preadv fs/read_write.c:1132 [inline] __do_sys_preadv fs/read_write.c:1179 [inline] __se_sys_preadv fs/read_write.c:1174 [inline] __x64_sys_preadv+0x197/0x2a0 fs/read_write.c:1174 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fec2078e929 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:00007fec216cc038 EFLAGS: 00000246 ORIG_RAX: 0000000000000127 RAX: ffffffffffffffda RBX: 00007fec209b5fa0 RCX: 00007fec2078e929 RDX: 0000000000000001 RSI: 00002000000003c0 RDI: 0000000000000004 RBP: 00007fec20810b39 R08: 000000000000000a R09: 0000000000000000 R10: 0000000000000085 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fec209b5fa0 R15: 00007ffc54b12928 ---------------- Code disassembly (best guess), 3 bytes skipped: 0: df 4d 8d fisttps -0x73(%rbp) 3: 34 19 xor $0x19,%al 5: 4d 89 f4 mov %r14,%r12 8: 4d 29 dc sub %r11,%r12 b: 49 83 fc 10 cmp $0x10,%r12 f: 7f 29 jg 0x3a 11: 4d 85 e4 test %r12,%r12 14: 0f 84 41 01 00 00 je 0x15b 1a: 4c 89 cb mov %r9,%rbx 1d: 48 f7 d3 not %rbx 20: 4c 01 fb add %r15,%rbx 23: 41 80 3b 00 cmpb $0x0,(%r11) * 27: 0f 85 de 01 00 00 jne 0x20b <-- trapping instruction 2d: 49 ff c3 inc %r11 30: 48 ff c3 inc %rbx 33: 75 ee jne 0x23 35: e9 21 01 00 00 jmp 0x15b 3a: 44 89 dd mov %r11d,%ebp