================================================================== BUG: KASAN: use-after-free in __hlist_del include/linux/list.h:791 [inline] BUG: KASAN: use-after-free in detach_timer kernel/time/timer.c:824 [inline] BUG: KASAN: use-after-free in expire_timers kernel/time/timer.c:1482 [inline] BUG: KASAN: use-after-free in __run_timers+0x7be/0xbe0 kernel/time/timer.c:1817 Write of size 8 at addr ffff8881e21ff1c8 by task syz.8.2481/9713 CPU: 1 PID: 9713 Comm: syz.8.2481 Not tainted 5.4.290-syzkaller-00017-g6b07fcd94a6a #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1d8/0x241 lib/dump_stack.c:118 print_address_description+0x8c/0x600 mm/kasan/report.c:384 __kasan_report+0xf3/0x120 mm/kasan/report.c:516 kasan_report+0x30/0x60 mm/kasan/common.c:653 __hlist_del include/linux/list.h:791 [inline] detach_timer kernel/time/timer.c:824 [inline] expire_timers kernel/time/timer.c:1482 [inline] __run_timers+0x7be/0xbe0 kernel/time/timer.c:1817 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1830 __do_softirq+0x23b/0x6b7 kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x195/0x1c0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:539 [inline] smp_apic_timer_interrupt+0x11a/0x490 arch/x86/kernel/apic/apic.c:1161 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:834 RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline] RIP: 0010:preempt_latency_start kernel/sched/core.c:3996 [inline] RIP: 0010:preempt_count_add+0x9d/0x180 kernel/sched/core.c:4019 Code: 8b 05 c3 9c bd 7e 25 ff ff ff 7f 39 d8 75 43 4c 8b 74 24 18 4c 89 f7 e8 e1 0e 07 00 85 c0 74 0a 45 31 f6 31 ff e8 d3 0e 07 00 <65> 48 8b 1d 8b 9c bd 7e 48 81 c3 78 09 00 00 48 89 d8 48 c1 e8 03 RSP: 0018:ffff8881c1c8ed20 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff84573f00 RDX: ffffc90008d5c000 RSI: 0000000000000040 RDI: ffffffff812fbdbc RBP: ffff8881c1c8f030 R08: ffffffff8153c592 R09: ffff8881c1c8f090 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff11038391e08 R13: ffffffff814338ea R14: ffffffff812fbdbc R15: dffffc0000000000 unwind_next_frame+0x17c/0x1ea0 arch/x86/kernel/unwind_orc.c:423 arch_stack_walk+0x111/0x140 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x118/0x1c0 kernel/stacktrace.c:123 save_stack mm/kasan/common.c:70 [inline] set_track mm/kasan/common.c:78 [inline] __kasan_kmalloc+0x171/0x210 mm/kasan/common.c:529 slab_post_alloc_hook mm/slab.h:584 [inline] slab_alloc_node mm/slub.c:2829 [inline] slab_alloc mm/slub.c:2837 [inline] __kmalloc+0x105/0x2e0 mm/slub.c:3909 kmalloc include/linux/slab.h:561 [inline] kzalloc include/linux/slab.h:690 [inline] new_dir fs/proc/proc_sysctl.c:973 [inline] get_subdir fs/proc/proc_sysctl.c:1018 [inline] __register_sysctl_table+0x983/0x11d0 fs/proc/proc_sysctl.c:1361 neigh_sysctl_register+0x454/0x530 net/core/neighbour.c:3714 addrconf_sysctl_register+0xac/0x180 net/ipv6/addrconf.c:7007 ipv6_add_dev+0xb34/0x10a0 net/ipv6/addrconf.c:444 addrconf_notify+0x59b/0xe50 net/ipv6/addrconf.c:3556 notifier_call_chain kernel/notifier.c:98 [inline] __raw_notifier_call_chain kernel/notifier.c:399 [inline] raw_notifier_call_chain+0x95/0x110 kernel/notifier.c:406 call_netdevice_notifiers_info net/core/dev.c:1670 [inline] call_netdevice_notifiers_extack net/core/dev.c:1682 [inline] call_netdevice_notifiers net/core/dev.c:1696 [inline] register_netdevice+0xeef/0x12a0 net/core/dev.c:9240 register_netdev+0x37/0x50 net/core/dev.c:9338 loopback_net_init+0x6f/0x140 drivers/net/loopback.c:214 ops_init+0x1d4/0x4a0 net/core/net_namespace.c:141 setup_net+0x214/0x990 net/core/net_namespace.c:348 copy_net_ns+0x30d/0x510 net/core/net_namespace.c:489 create_new_namespaces+0x47a/0x570 kernel/nsproxy.c:103 copy_namespaces+0x169/0x1b0 kernel/nsproxy.c:161 copy_process+0x12da/0x3230 kernel/fork.c:2055 _do_fork+0x197/0x900 kernel/fork.c:2399 __do_sys_clone kernel/fork.c:2557 [inline] __se_sys_clone kernel/fork.c:2538 [inline] __x64_sys_clone+0x26b/0x2c0 kernel/fork.c:2538 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 RIP: 0033:0x7f75d0a25169 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:00007f75cf08efe8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007f75d0c3dfa0 RCX: 00007f75d0a25169 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040b04000 RBP: 00007f75d0aa62a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f75d0c3dfa0 R15: 00007fff56e01898 Allocated by task 9636: save_stack mm/kasan/common.c:70 [inline] set_track mm/kasan/common.c:78 [inline] __kasan_kmalloc+0x171/0x210 mm/kasan/common.c:529 slab_post_alloc_hook mm/slab.h:584 [inline] slab_alloc_node mm/slub.c:2829 [inline] slab_alloc mm/slub.c:2837 [inline] kmem_cache_alloc+0xd9/0x250 mm/slub.c:2842 shmem_alloc_inode+0x16/0x30 mm/shmem.c:3719 alloc_inode fs/inode.c:231 [inline] new_inode_pseudo+0x60/0x210 fs/inode.c:966 new_inode+0x25/0x1d0 fs/inode.c:995 shmem_get_inode+0x10b/0x620 mm/shmem.c:2252 shmem_symlink+0x118/0x5f0 mm/shmem.c:3068 vfs_symlink+0x36c/0x500 fs/namei.c:4276 do_symlinkat+0x19b/0x400 fs/namei.c:4303 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 Freed by task 17: save_stack mm/kasan/common.c:70 [inline] set_track mm/kasan/common.c:78 [inline] kasan_set_free_info mm/kasan/common.c:345 [inline] __kasan_slab_free+0x1b5/0x270 mm/kasan/common.c:487 slab_free_hook mm/slub.c:1455 [inline] slab_free_freelist_hook mm/slub.c:1494 [inline] slab_free mm/slub.c:3080 [inline] kmem_cache_free+0x10b/0x2c0 mm/slub.c:3096 __rcu_reclaim kernel/rcu/rcu.h:222 [inline] rcu_do_batch+0x492/0xa00 kernel/rcu/tree.c:2167 rcu_core+0x4c8/0xcb0 kernel/rcu/tree.c:2387 __do_softirq+0x23b/0x6b7 kernel/softirq.c:292 The buggy address belongs to the object at ffff8881e21ff090 which belongs to the cache shmem_inode_cache of size 760 The buggy address is located 312 bytes inside of 760-byte region [ffff8881e21ff090, ffff8881e21ff388) The buggy address belongs to the page: page:ffffea0007887f00 refcount:1 mapcount:0 mapping:ffff8881f5cfe500 index:0x0 compound_mapcount: 0 flags: 0x8000000000010200(slab|head) raw: 8000000000010200 dead000000000100 dead000000000122 ffff8881f5cfe500 raw: 0000000000000000 0000000000120012 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL) set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook mm/page_alloc.c:2165 [inline] prep_new_page+0x18f/0x370 mm/page_alloc.c:2171 get_page_from_freelist+0x2d13/0x2d90 mm/page_alloc.c:3794 __alloc_pages_nodemask+0x393/0x840 mm/page_alloc.c:4893 alloc_slab_page+0x39/0x3c0 mm/slub.c:343 allocate_slab mm/slub.c:1683 [inline] new_slab+0x97/0x440 mm/slub.c:1749 new_slab_objects mm/slub.c:2505 [inline] ___slab_alloc+0x2fe/0x490 mm/slub.c:2667 __slab_alloc+0x62/0xa0 mm/slub.c:2707 slab_alloc_node mm/slub.c:2792 [inline] slab_alloc mm/slub.c:2837 [inline] kmem_cache_alloc+0x109/0x250 mm/slub.c:2842 shmem_alloc_inode+0x16/0x30 mm/shmem.c:3719 alloc_inode fs/inode.c:231 [inline] new_inode_pseudo+0x60/0x210 fs/inode.c:966 new_inode+0x25/0x1d0 fs/inode.c:995 shmem_get_inode+0x10b/0x620 mm/shmem.c:2252 shmem_symlink+0x118/0x5f0 mm/shmem.c:3068 vfs_symlink+0x36c/0x500 fs/namei.c:4276 do_symlinkat+0x19b/0x400 fs/namei.c:4303 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1176 [inline] __free_pages_ok+0x847/0x950 mm/page_alloc.c:1438 free_the_page mm/page_alloc.c:4955 [inline] __free_pages+0x91/0x140 mm/page_alloc.c:4961 bpf_check+0x8aeb/0xb3e0 kernel/bpf/verifier.c:9731 bpf_prog_load kernel/bpf/syscall.c:1724 [inline] __do_sys_bpf kernel/bpf/syscall.c:2891 [inline] __se_sys_bpf+0x8139/0xbcb0 kernel/bpf/syscall.c:2849 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 Memory state around the buggy address: ffff8881e21ff080: fc fc fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881e21ff100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8881e21ff180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8881e21ff200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881e21ff280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor instruction fetch in kernel mode #PF: error_code(0x0010) - not-present page PGD 1d76db067 P4D 1d76db067 PUD 0 Oops: 0010 [#1] PREEMPT SMP KASAN CPU: 1 PID: 9713 Comm: syz.8.2481 Tainted: G B 5.4.290-syzkaller-00017-g6b07fcd94a6a #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 RIP: 0010:0x0 Code: Bad RIP value. RSP: 0018:ffff8881f6f09d18 EFLAGS: 00010202 RAX: ffffffff8154e8ca RBX: 0000000000000101 RCX: ffff8881d7d03f00 RDX: 0000000000000101 RSI: 0000000000000000 RDI: ffff8881e21ff1c0 RBP: ffff8881f6f09ec8 R08: ffffffff8154e50e R09: 0000000000000003 R10: ffffffffffffffff R11: dffffc0000000001 R12: 0000000100001070 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881e21ff1c0 FS: 00007f75cf08f6c0(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 00000001ecef3000 CR4: 00000000003406a0 DR0: 0000000000000000 DR1: 0000400000000300 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: call_timer_fn+0x36/0x390 kernel/time/timer.c:1448 expire_timers kernel/time/timer.c:1493 [inline] __run_timers+0x879/0xbe0 kernel/time/timer.c:1817 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1830 __do_softirq+0x23b/0x6b7 kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x195/0x1c0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:539 [inline] smp_apic_timer_interrupt+0x11a/0x490 arch/x86/kernel/apic/apic.c:1161 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:834 RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline] RIP: 0010:preempt_latency_start kernel/sched/core.c:3996 [inline] RIP: 0010:preempt_count_add+0x9d/0x180 kernel/sched/core.c:4019 Code: 8b 05 c3 9c bd 7e 25 ff ff ff 7f 39 d8 75 43 4c 8b 74 24 18 4c 89 f7 e8 e1 0e 07 00 85 c0 74 0a 45 31 f6 31 ff e8 d3 0e 07 00 <65> 48 8b 1d 8b 9c bd 7e 48 81 c3 78 09 00 00 48 89 d8 48 c1 e8 03 RSP: 0018:ffff8881c1c8ed20 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff84573f00 RDX: ffffc90008d5c000 RSI: 0000000000000040 RDI: ffffffff812fbdbc RBP: ffff8881c1c8f030 R08: ffffffff8153c592 R09: ffff8881c1c8f090 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff11038391e08 R13: ffffffff814338ea R14: ffffffff812fbdbc R15: dffffc0000000000 unwind_next_frame+0x17c/0x1ea0 arch/x86/kernel/unwind_orc.c:423 arch_stack_walk+0x111/0x140 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x118/0x1c0 kernel/stacktrace.c:123 save_stack mm/kasan/common.c:70 [inline] set_track mm/kasan/common.c:78 [inline] __kasan_kmalloc+0x171/0x210 mm/kasan/common.c:529 slab_post_alloc_hook mm/slab.h:584 [inline] slab_alloc_node mm/slub.c:2829 [inline] slab_alloc mm/slub.c:2837 [inline] __kmalloc+0x105/0x2e0 mm/slub.c:3909 kmalloc include/linux/slab.h:561 [inline] kzalloc include/linux/slab.h:690 [inline] new_dir fs/proc/proc_sysctl.c:973 [inline] get_subdir fs/proc/proc_sysctl.c:1018 [inline] __register_sysctl_table+0x983/0x11d0 fs/proc/proc_sysctl.c:1361 neigh_sysctl_register+0x454/0x530 net/core/neighbour.c:3714 addrconf_sysctl_register+0xac/0x180 net/ipv6/addrconf.c:7007 ipv6_add_dev+0xb34/0x10a0 net/ipv6/addrconf.c:444 addrconf_notify+0x59b/0xe50 net/ipv6/addrconf.c:3556 notifier_call_chain kernel/notifier.c:98 [inline] __raw_notifier_call_chain kernel/notifier.c:399 [inline] raw_notifier_call_chain+0x95/0x110 kernel/notifier.c:406 call_netdevice_notifiers_info net/core/dev.c:1670 [inline] call_netdevice_notifiers_extack net/core/dev.c:1682 [inline] call_netdevice_notifiers net/core/dev.c:1696 [inline] register_netdevice+0xeef/0x12a0 net/core/dev.c:9240 register_netdev+0x37/0x50 net/core/dev.c:9338 loopback_net_init+0x6f/0x140 drivers/net/loopback.c:214 ops_init+0x1d4/0x4a0 net/core/net_namespace.c:141 setup_net+0x214/0x990 net/core/net_namespace.c:348 copy_net_ns+0x30d/0x510 net/core/net_namespace.c:489 create_new_namespaces+0x47a/0x570 kernel/nsproxy.c:103 copy_namespaces+0x169/0x1b0 kernel/nsproxy.c:161 copy_process+0x12da/0x3230 kernel/fork.c:2055 _do_fork+0x197/0x900 kernel/fork.c:2399 __do_sys_clone kernel/fork.c:2557 [inline] __se_sys_clone kernel/fork.c:2538 [inline] __x64_sys_clone+0x26b/0x2c0 kernel/fork.c:2538 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 RIP: 0033:0x7f75d0a25169 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:00007f75cf08efe8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007f75d0c3dfa0 RCX: 00007f75d0a25169 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040b04000 RBP: 00007f75d0aa62a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f75d0c3dfa0 R15: 00007fff56e01898 Modules linked in: CR2: 0000000000000000 ---[ end trace 9304255c885413a1 ]--- RIP: 0010:0x0 Code: Bad RIP value. RSP: 0018:ffff8881f6f09d18 EFLAGS: 00010202 RAX: ffffffff8154e8ca RBX: 0000000000000101 RCX: ffff8881d7d03f00 RDX: 0000000000000101 RSI: 0000000000000000 RDI: ffff8881e21ff1c0 RBP: ffff8881f6f09ec8 R08: ffffffff8154e50e R09: 0000000000000003 R10: ffffffffffffffff R11: dffffc0000000001 R12: 0000000100001070 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881e21ff1c0 FS: 00007f75cf08f6c0(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 00000001ecef3000 CR4: 00000000003406a0 DR0: 0000000000000000 DR1: 0000400000000300 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 ---------------- Code disassembly (best guess): 0: 8b 05 c3 9c bd 7e mov 0x7ebd9cc3(%rip),%eax # 0x7ebd9cc9 6: 25 ff ff ff 7f and $0x7fffffff,%eax b: 39 d8 cmp %ebx,%eax d: 75 43 jne 0x52 f: 4c 8b 74 24 18 mov 0x18(%rsp),%r14 14: 4c 89 f7 mov %r14,%rdi 17: e8 e1 0e 07 00 call 0x70efd 1c: 85 c0 test %eax,%eax 1e: 74 0a je 0x2a 20: 45 31 f6 xor %r14d,%r14d 23: 31 ff xor %edi,%edi 25: e8 d3 0e 07 00 call 0x70efd * 2a: 65 48 8b 1d 8b 9c bd mov %gs:0x7ebd9c8b(%rip),%rbx # 0x7ebd9cbd <-- trapping instruction 31: 7e 32: 48 81 c3 78 09 00 00 add $0x978,%rbx 39: 48 89 d8 mov %rbx,%rax 3c: 48 c1 e8 03 shr $0x3,%rax