================================================================== BUG: KASAN: slab-out-of-bounds in hlist_add_head include/linux/list.h:814 [inline] BUG: KASAN: slab-out-of-bounds in enqueue_timer+0x9e/0x2c0 kernel/time/timer.c:541 Write of size 8 at addr ffff8881eba071c8 by task syz.0.303/1499 CPU: 0 PID: 1499 Comm: syz.0.303 Not tainted 5.4.292-syzkaller-00021-gcd8e74fa0fa3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack+0x1e/0x20 lib/dump_stack.c:77 dump_stack+0x15b/0x1b8 lib/dump_stack.c:118 print_address_description+0x8d/0x4c0 mm/kasan/report.c:384 __kasan_report+0xef/0x120 mm/kasan/report.c:516 kasan_report+0x30/0x60 mm/kasan/common.c:653 __asan_report_store8_noabort+0x17/0x20 mm/kasan/generic_report.c:137 hlist_add_head include/linux/list.h:814 [inline] enqueue_timer+0x9e/0x2c0 kernel/time/timer.c:541 __internal_add_timer kernel/time/timer.c:554 [inline] internal_add_timer+0x208/0x3e0 kernel/time/timer.c:604 __mod_timer+0x5ab/0x1150 kernel/time/timer.c:1065 mod_timer+0x1f/0x30 kernel/time/timer.c:1117 can_stat_update+0xbab/0xc40 net/can/proc.c:186 call_timer_fn+0x3c/0x380 kernel/time/timer.c:1448 expire_timers kernel/time/timer.c:1493 [inline] __run_timers+0x81d/0xb60 kernel/time/timer.c:1817 run_timer_softirq+0x6a/0xf0 kernel/time/timer.c:1830 __do_softirq+0x236/0x660 kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x197/0x1c0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:539 [inline] smp_apic_timer_interrupt+0x11d/0x490 arch/x86/kernel/apic/apic.c:1161 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:834 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline] RIP: 0010:_raw_spin_unlock_irq+0x49/0x70 kernel/locking/spinlock.c:199 Code: 12 48 89 fb 48 c7 c7 b0 2d cb 85 e8 31 7f 62 fd 48 89 df 48 83 3d c6 33 a0 01 00 74 27 e8 93 37 1d fd 66 90 fb bf 01 00 00 00 72 7a 16 fd 65 8b 05 87 93 d7 7b 85 c0 74 03 5b 5d c3 e8 7f 4d RSP: 0018:ffff8881e943f048 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000001 RBX: dffffc0000000000 RCX: dffffc0000000000 RDX: 0000000040000002 RSI: 0000000000000000 RDI: 0000000000000001 RBP: ffff8881e943f050 R08: dffffc0000000000 R09: fffffbfff0c57781 R10: fffffbfff0c57781 R11: 1ffffffff0c57780 R12: ffff8881f6e57b40 R13: ffff8881e3cf0ff8 R14: 0000000000000000 R15: ffff8881eae72f40 finish_lock_switch kernel/sched/core.c:3349 [inline] finish_task_switch+0x12e/0x590 kernel/sched/core.c:3449 context_switch kernel/sched/core.c:3613 [inline] __schedule+0xa57/0x12a0 kernel/sched/core.c:4309 preempt_schedule_irq+0x9b/0x110 kernel/sched/core.c:4560 retint_kernel+0x1b/0x1b RIP: 0010:find_stack lib/stackdepot.c:183 [inline] RIP: 0010:stack_depot_save+0x14b/0x4c0 lib/stackdepot.c:245 Code: e6 c1 c6 04 29 f1 41 31 cb c1 c1 0e 41 29 cb 45 31 dc 41 c1 c3 18 45 29 dc 44 89 e3 81 e3 ff ff 0f 00 4c 8b 2c dd 80 18 5c 86 <4d> 85 ed 74 59 44 89 ff eb 09 4d 8b 6d 00 4d 85 ed 74 4b 45 39 65 RSP: 0018:ffff8881e943f2f0 EFLAGS: 00000206 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000000 RBX: 0000000000091696 RCX: 00000000806fb1e1 RDX: 0000000000000800 RSI: 000000002ce0d398 RDI: 0000000000000002 RBP: ffff8881e943f340 R08: 0000000065299b0b R09: 000000004ce87342 R10: 00000000c057d926 R11: 0000000009a5809a R12: 000000001da91696 R13: ffff8881ebd4ed10 R14: ffff8881e943f350 R15: 000000000000000d save_stack mm/kasan/common.c:72 [inline] set_track mm/kasan/common.c:78 [inline] kasan_set_free_info mm/kasan/common.c:345 [inline] __kasan_slab_free+0x223/0x280 mm/kasan/common.c:487 kasan_slab_free+0xe/0x10 mm/kasan/common.c:496 slab_free_hook mm/slub.c:1455 [inline] slab_free_freelist_hook+0xb7/0x180 mm/slub.c:1494 slab_free mm/slub.c:3080 [inline] kfree+0xbe/0x260 mm/slub.c:4071 kvfree+0x4c/0x50 mm/util.c:625 __vunmap+0x801/0x8a0 mm/vmalloc.c:2264 __vfree mm/vmalloc.c:2308 [inline] vfree+0x61/0x90 mm/vmalloc.c:2338 bpf_check+0x8369/0x9cf0 kernel/bpf/verifier.c:9729 bpf_prog_load+0xa5f/0xe10 kernel/bpf/syscall.c:1724 __do_sys_bpf kernel/bpf/syscall.c:2891 [inline] __se_sys_bpf+0x435/0x570 kernel/bpf/syscall.c:2849 __x64_sys_bpf+0x7b/0x90 kernel/bpf/syscall.c:2849 do_syscall_64+0xcf/0x170 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 RIP: 0033:0x7f3eb2df7969 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:00007f3eb1460038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f3eb301efa0 RCX: 00007f3eb2df7969 RDX: 0000000000000080 RSI: 00002000000000c0 RDI: 0000000000000005 RBP: 00007f3eb2e79ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f3eb301efa0 R15: 00007ffc52023a38 The buggy address belongs to the page: page:ffffea0007ae8100 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 compound_mapcount: 0 flags: 0x8000000000010000(head) raw: 8000000000010000 dead000000000100 dead000000000122 0000000000000000 raw: 0000000000000000 0000000000000000 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 0x152dc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_ZERO) set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook mm/page_alloc.c:2165 [inline] prep_new_page+0x35e/0x370 mm/page_alloc.c:2171 get_page_from_freelist+0x1296/0x1310 mm/page_alloc.c:3794 __alloc_pages_nodemask+0x202/0x4b0 mm/page_alloc.c:4894 __alloc_pages include/linux/gfp.h:503 [inline] __alloc_pages_node include/linux/gfp.h:516 [inline] alloc_pages_node include/linux/gfp.h:530 [inline] kmalloc_order mm/slab_common.c:1342 [inline] kmalloc_order_trace+0x31/0x100 mm/slab_common.c:1358 kmalloc_large include/linux/slab.h:485 [inline] __kmalloc+0x162/0x2f0 mm/slub.c:3902 __kmalloc_node include/linux/slab.h:422 [inline] kmalloc_node include/linux/slab.h:599 [inline] kvmalloc_node+0x88/0xf0 mm/util.c:596 kvmalloc include/linux/mm.h:761 [inline] kvzalloc include/linux/mm.h:769 [inline] bpf_check+0xfb/0x9cf0 kernel/bpf/verifier.c:9561 bpf_prog_load+0xa5f/0xe10 kernel/bpf/syscall.c:1724 __do_sys_bpf kernel/bpf/syscall.c:2891 [inline] __se_sys_bpf+0x435/0x570 kernel/bpf/syscall.c:2849 __x64_sys_bpf+0x7b/0x90 kernel/bpf/syscall.c:2849 do_syscall_64+0xcf/0x170 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 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+0x7e4/0x910 mm/page_alloc.c:1438 free_the_page mm/page_alloc.c:4956 [inline] __free_pages+0x8c/0x110 mm/page_alloc.c:4962 kfree+0x1ca/0x260 mm/slub.c:4068 kvfree+0x4c/0x50 mm/util.c:625 netdev_freemem+0x3f/0x60 net/core/dev.c:9583 netdev_release+0x7f/0xb0 net/core/net-sysfs.c:1743 device_release+0x70/0x1a0 drivers/base/core.c:1776 kobject_cleanup lib/kobject.c:716 [inline] kobject_release lib/kobject.c:747 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x1fe/0x2c0 lib/kobject.c:764 netdev_run_todo+0xae4/0xc70 net/core/dev.c:9488 rtnl_unlock+0xe/0x10 net/core/rtnetlink.c:112 tun_detach drivers/net/tun.c:766 [inline] tun_chr_close+0xc4/0x140 drivers/net/tun.c:3563 __fput+0x2a3/0x730 fs/file_table.c:281 ____fput+0x15/0x20 fs/file_table.c:314 task_work_run+0x146/0x170 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x195/0x1b0 arch/x86/entry/common.c:163 prepare_exit_to_usermode+0x18e/0x1f0 arch/x86/entry/common.c:194 Memory state around the buggy address: ffff8881eba07080: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe ffff8881eba07100: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe >ffff8881eba07180: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe ^ ffff8881eba07200: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe ffff8881eba07280: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe ================================================================== BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor instruction fetch in kernel mode #PF: error_code(0x0010) - not-present page PGD 1eb3ac067 P4D 1eb3ac067 PUD 0 Oops: 0010 [#1] PREEMPT SMP KASAN CPU: 0 PID: 1499 Comm: syz.0.303 Tainted: G B 5.4.292-syzkaller-00021-gcd8e74fa0fa3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:0x0 Code: Bad RIP value. RSP: 0018:ffff8881f6e09cf0 EFLAGS: 00010202 RAX: ffffffff8150a590 RBX: 0000000000000102 RCX: ffff8881eae72f40 RDX: 0000000000000102 RSI: 0000000000000000 RDI: ffff8881eba071c0 RBP: ffff8881f6e09d30 R08: 0000000000000004 R09: 0000000000000003 R10: ffffed103edc1398 R11: 1ffff1103edc1398 R12: 00000000ffffa248 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881eba071c0 FS: 00007f3eb14606c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 00000001ed6f0000 CR4: 00000000003406b0 DR0: 0000000000000000 DR1: 0000200000000300 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: call_timer_fn+0x3c/0x380 kernel/time/timer.c:1448 expire_timers kernel/time/timer.c:1493 [inline] __run_timers+0x81d/0xb60 kernel/time/timer.c:1817 run_timer_softirq+0x6a/0xf0 kernel/time/timer.c:1830 __do_softirq+0x236/0x660 kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x197/0x1c0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:539 [inline] smp_apic_timer_interrupt+0x11d/0x490 arch/x86/kernel/apic/apic.c:1161 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:834 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline] RIP: 0010:_raw_spin_unlock_irq+0x49/0x70 kernel/locking/spinlock.c:199 Code: 12 48 89 fb 48 c7 c7 b0 2d cb 85 e8 31 7f 62 fd 48 89 df 48 83 3d c6 33 a0 01 00 74 27 e8 93 37 1d fd 66 90 fb bf 01 00 00 00 72 7a 16 fd 65 8b 05 87 93 d7 7b 85 c0 74 03 5b 5d c3 e8 7f 4d RSP: 0018:ffff8881e943f048 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000001 RBX: dffffc0000000000 RCX: dffffc0000000000 RDX: 0000000040000002 RSI: 0000000000000000 RDI: 0000000000000001 RBP: ffff8881e943f050 R08: dffffc0000000000 R09: fffffbfff0c57781 R10: fffffbfff0c57781 R11: 1ffffffff0c57780 R12: ffff8881f6e57b40 R13: ffff8881e3cf0ff8 R14: 0000000000000000 R15: ffff8881eae72f40 finish_lock_switch kernel/sched/core.c:3349 [inline] finish_task_switch+0x12e/0x590 kernel/sched/core.c:3449 context_switch kernel/sched/core.c:3613 [inline] __schedule+0xa57/0x12a0 kernel/sched/core.c:4309 preempt_schedule_irq+0x9b/0x110 kernel/sched/core.c:4560 retint_kernel+0x1b/0x1b RIP: 0010:find_stack lib/stackdepot.c:183 [inline] RIP: 0010:stack_depot_save+0x14b/0x4c0 lib/stackdepot.c:245 Code: e6 c1 c6 04 29 f1 41 31 cb c1 c1 0e 41 29 cb 45 31 dc 41 c1 c3 18 45 29 dc 44 89 e3 81 e3 ff ff 0f 00 4c 8b 2c dd 80 18 5c 86 <4d> 85 ed 74 59 44 89 ff eb 09 4d 8b 6d 00 4d 85 ed 74 4b 45 39 65 RSP: 0018:ffff8881e943f2f0 EFLAGS: 00000206 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000000 RBX: 0000000000091696 RCX: 00000000806fb1e1 RDX: 0000000000000800 RSI: 000000002ce0d398 RDI: 0000000000000002 RBP: ffff8881e943f340 R08: 0000000065299b0b R09: 000000004ce87342 R10: 00000000c057d926 R11: 0000000009a5809a R12: 000000001da91696 R13: ffff8881ebd4ed10 R14: ffff8881e943f350 R15: 000000000000000d save_stack mm/kasan/common.c:72 [inline] set_track mm/kasan/common.c:78 [inline] kasan_set_free_info mm/kasan/common.c:345 [inline] __kasan_slab_free+0x223/0x280 mm/kasan/common.c:487 kasan_slab_free+0xe/0x10 mm/kasan/common.c:496 slab_free_hook mm/slub.c:1455 [inline] slab_free_freelist_hook+0xb7/0x180 mm/slub.c:1494 slab_free mm/slub.c:3080 [inline] kfree+0xbe/0x260 mm/slub.c:4071 kvfree+0x4c/0x50 mm/util.c:625 __vunmap+0x801/0x8a0 mm/vmalloc.c:2264 __vfree mm/vmalloc.c:2308 [inline] vfree+0x61/0x90 mm/vmalloc.c:2338 bpf_check+0x8369/0x9cf0 kernel/bpf/verifier.c:9729 bpf_prog_load+0xa5f/0xe10 kernel/bpf/syscall.c:1724 __do_sys_bpf kernel/bpf/syscall.c:2891 [inline] __se_sys_bpf+0x435/0x570 kernel/bpf/syscall.c:2849 __x64_sys_bpf+0x7b/0x90 kernel/bpf/syscall.c:2849 do_syscall_64+0xcf/0x170 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 RIP: 0033:0x7f3eb2df7969 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:00007f3eb1460038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f3eb301efa0 RCX: 00007f3eb2df7969 RDX: 0000000000000080 RSI: 00002000000000c0 RDI: 0000000000000005 RBP: 00007f3eb2e79ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f3eb301efa0 R15: 00007ffc52023a38 Modules linked in: CR2: 0000000000000000 ---[ end trace 54bdaf414f6f8380 ]--- RIP: 0010:0x0 Code: Bad RIP value. RSP: 0018:ffff8881f6e09cf0 EFLAGS: 00010202 RAX: ffffffff8150a590 RBX: 0000000000000102 RCX: ffff8881eae72f40 RDX: 0000000000000102 RSI: 0000000000000000 RDI: ffff8881eba071c0 RBP: ffff8881f6e09d30 R08: 0000000000000004 R09: 0000000000000003 R10: ffffed103edc1398 R11: 1ffff1103edc1398 R12: 00000000ffffa248 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881eba071c0 FS: 00007f3eb14606c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 00000001ed6f0000 CR4: 00000000003406b0 DR0: 0000000000000000 DR1: 0000200000000300 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 ---------------- Code disassembly (best guess): 0: 12 48 89 adc -0x77(%rax),%cl 3: fb sti 4: 48 c7 c7 b0 2d cb 85 mov $0xffffffff85cb2db0,%rdi b: e8 31 7f 62 fd call 0xfd627f41 10: 48 89 df mov %rbx,%rdi 13: 48 83 3d c6 33 a0 01 cmpq $0x0,0x1a033c6(%rip) # 0x1a033e1 1a: 00 1b: 74 27 je 0x44 1d: e8 93 37 1d fd call 0xfd1d37b5 22: 66 90 xchg %ax,%ax 24: fb sti 25: bf 01 00 00 00 mov $0x1,%edi * 2a: e8 72 7a 16 fd call 0xfd167aa1 <-- trapping instruction 2f: 65 8b 05 87 93 d7 7b mov %gs:0x7bd79387(%rip),%eax # 0x7bd793bd 36: 85 c0 test %eax,%eax 38: 74 03 je 0x3d 3a: 5b pop %rbx 3b: 5d pop %rbp 3c: c3 ret 3d: e8 .byte 0xe8 3e: 7f 4d jg 0x8d