================================================================== 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 ffff8881ebb4f1c8 by task syz.9.945/3844 CPU: 0 PID: 3844 Comm: syz.9.945 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:page_dup_rmap include/linux/rmap.h:208 [inline] RIP: 0010:copy_one_pte mm/memory.c:805 [inline] RIP: 0010:copy_pte_range mm/memory.c:855 [inline] RIP: 0010:copy_pmd_range mm/memory.c:906 [inline] RIP: 0010:copy_pud_range mm/memory.c:940 [inline] RIP: 0010:copy_p4d_range mm/memory.c:962 [inline] RIP: 0010:copy_page_range+0xe62/0x1730 mm/memory.c:1024 Code: e8 13 fb da ff 41 f6 c5 01 0f 85 95 02 00 00 e8 34 f7 da ff 4d 89 f5 49 8d 7d 34 be 04 00 00 00 e8 73 cb 08 00 f0 41 ff 45 34 <4c> 89 f7 48 83 c7 30 be 04 00 00 00 e8 5d cb 08 00 f0 41 ff 46 30 RSP: 0018:ffff8881e8e4f840 EFLAGS: 00000206 ORIG_RAX: ffffffffffffff13 RAX: ffffffff81848701 RBX: ffffea0007653808 RCX: ffffffff818487bd RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffea0007653834 RBP: ffff8881e8e4fa50 R08: dffffc0000000000 R09: fffff94000eca707 R10: fffff94000eca707 R11: 1ffffd4000eca706 R12: 1ffffd4000eca701 R13: ffffea0007653800 R14: ffffea0007653800 R15: 80000001d94e0007 dup_mmap kernel/fork.c:608 [inline] dup_mm kernel/fork.c:1379 [inline] copy_mm+0xb65/0x1150 kernel/fork.c:1435 copy_process+0x1163/0x2cf0 kernel/fork.c:2052 _do_fork+0x190/0x860 kernel/fork.c:2399 __do_sys_clone kernel/fork.c:2557 [inline] __se_sys_clone kernel/fork.c:2538 [inline] __x64_sys_clone+0x12e/0x160 kernel/fork.c:2538 do_syscall_64+0xcf/0x170 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 RIP: 0033:0x7f7e0fbd2969 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:00007f7e0e23afe8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007f7e0fdf9fa0 RCX: 00007f7e0fbd2969 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000042164000 RBP: 00007f7e0fc54ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f7e0fdf9fa0 R15: 00007ffc29391168 Allocated by task 3765: save_stack mm/kasan/common.c:70 [inline] set_track mm/kasan/common.c:78 [inline] __kasan_kmalloc+0x162/0x200 mm/kasan/common.c:529 kasan_kmalloc+0xd/0x20 mm/kasan/common.c:543 __kmalloc+0x12a/0x2f0 mm/slub.c:3913 kmalloc_array include/linux/slab.h:618 [inline] realloc_stack_state kernel/bpf/verifier.c:595 [inline] realloc_func_state+0x305/0x5b0 kernel/bpf/verifier.c:611 copy_func_state kernel/bpf/verifier.c:704 [inline] copy_verifier_state+0x65f/0xc20 kernel/bpf/verifier.c:751 push_stack+0x156/0x480 kernel/bpf/verifier.c:819 check_cond_jmp_op+0x5c3/0x17f0 kernel/bpf/verifier.c:6192 do_check+0x5058/0x8a60 kernel/bpf/verifier.c:8109 bpf_check+0x208a/0x9cf0 kernel/bpf/verifier.c:9637 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 Freed by task 3765: 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+0x1c3/0x280 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 free_func_state kernel/bpf/verifier.c:671 [inline] free_verifier_state+0xd6/0x220 kernel/bpf/verifier.c:688 pop_stack kernel/bpf/verifier.c:795 [inline] do_check+0x65d1/0x8a60 kernel/bpf/verifier.c:8098 bpf_check+0x208a/0x9cf0 kernel/bpf/verifier.c:9637 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 The buggy address belongs to the object at ffff8881ebb4f000 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 200 bytes to the right of 256-byte region [ffff8881ebb4f000, ffff8881ebb4f100) The buggy address belongs to the page: page:ffffea0007aed380 refcount:1 mapcount:0 mapping:ffff8881f5c02780 index:0x0 compound_mapcount: 0 flags: 0x8000000000010200(slab|head) raw: 8000000000010200 dead000000000100 dead000000000122 ffff8881f5c02780 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 1, 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+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_slab_page+0x3c/0x3b0 mm/slub.c:343 allocate_slab mm/slub.c:1683 [inline] new_slab+0x93/0x420 mm/slub.c:1749 new_slab_objects mm/slub.c:2505 [inline] ___slab_alloc+0x29e/0x420 mm/slub.c:2667 __slab_alloc+0x63/0xa0 mm/slub.c:2707 slab_alloc_node mm/slub.c:2792 [inline] slab_alloc mm/slub.c:2837 [inline] __kmalloc+0x176/0x2f0 mm/slub.c:3909 kmalloc_array include/linux/slab.h:618 [inline] realloc_stack_state kernel/bpf/verifier.c:595 [inline] realloc_func_state+0x305/0x5b0 kernel/bpf/verifier.c:611 copy_func_state kernel/bpf/verifier.c:704 [inline] copy_verifier_state+0x65f/0xc20 kernel/bpf/verifier.c:751 push_stack+0x156/0x480 kernel/bpf/verifier.c:819 check_cond_jmp_op+0x5c3/0x17f0 kernel/bpf/verifier.c:6192 do_check+0x5058/0x8a60 kernel/bpf/verifier.c:8109 bpf_check+0x208a/0x9cf0 kernel/bpf/verifier.c:9637 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 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: ffff8881ebb4f080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881ebb4f100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8881ebb4f180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff8881ebb4f200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881ebb4f280: 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 1d6dd1067 P4D 1d6dd1067 PUD 0 Oops: 0010 [#1] PREEMPT SMP KASAN CPU: 0 PID: 3795 Comm: syz.9.930 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: ffff8881df6aaf40 RDX: 0000000080000102 RSI: 0000000000000000 RDI: ffff8881ebb4f1c0 RBP: ffff8881f6e09d30 R08: 0000000000000004 R09: 0000000000000003 R10: ffffed103edc1398 R11: 1ffff1103edc1398 R12: 00000000ffffb058 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881ebb4f1c0 FS: 00007f7e0e21a6c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 00000001e1135000 CR4: 00000000003406b0 DR0: 0000000000000000 DR1: 0000000000000000 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_irqrestore include/linux/spinlock_api_smp.h:161 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x51/0x80 kernel/locking/spinlock.c:191 Code: 89 fe 48 c7 c7 b0 2d cb 85 e8 ab 7f 62 fd 4c 89 f7 48 83 3d 40 34 a0 01 00 74 34 e8 0d 38 1d fd 66 90 48 89 5d e8 ff 75 e8 9d 01 00 00 00 e8 e5 7a 16 fd 65 8b 05 fa 93 d7 7b 85 c0 74 09 48 RSP: 0018:ffff8881db8c6da8 EFLAGS: 00000a06 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000001 RBX: 0000000000000a06 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: 0000000000000a06 RDI: ffffffff862911c0 RBP: ffff8881db8c6dc0 R08: dffffc0000000000 R09: fffff94000e3b901 R10: fffff94000e3b901 R11: 1ffffd4000e3b900 R12: dffffc0000000000 R13: ffff8881f6e55318 R14: 1ffff1103edcaa54 R15: 0000000000000a06 spin_unlock_irqrestore include/linux/spinlock.h:393 [inline] pagevec_lru_move_fn+0x17e/0x210 mm/swap.c:214 __pagevec_lru_add mm/swap.c:966 [inline] __lru_cache_add+0x1d1/0x250 mm/swap.c:406 lru_cache_add_anon+0xe5/0x110 mm/swap.c:418 shmem_getpage_gfp+0x1562/0x2370 mm/shmem.c:1899 shmem_getpage mm/shmem.c:154 [inline] shmem_write_begin+0xce/0x1b0 mm/shmem.c:2447 generic_perform_write+0x2b8/0x500 mm/filemap.c:3450 __generic_file_write_iter+0x24b/0x480 mm/filemap.c:3579 generic_file_write_iter+0x48d/0x620 mm/filemap.c:3611 call_write_iter include/linux/fs.h:1991 [inline] new_sync_write fs/read_write.c:483 [inline] __vfs_write+0x480/0x5d0 fs/read_write.c:496 __kernel_write+0xea/0x320 fs/read_write.c:515 dump_emit+0x1c0/0x2c0 fs/coredump.c:838 elf_core_dump+0x3465/0x3bd0 fs/binfmt_elf.c:2352 do_coredump+0x1d8c/0x2ab0 fs/coredump.c:801 get_signal+0xdb7/0x13d0 kernel/signal.c:2732 do_signal+0xad/0xda0 arch/x86/kernel/signal.c:809 exit_to_usermode_loop+0xc4/0x1b0 arch/x86/entry/common.c:159 prepare_exit_to_usermode+0x18e/0x1f0 arch/x86/entry/common.c:194 ret_from_intr+0x1c/0x1c RIP: 0033:0x0 Code: Bad RIP value. RSP: 002b:0000200000000148 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007f7e0fdfa080 RCX: 00007f7e0fbd2969 RDX: 0000000000000000 RSI: 0000200000000140 RDI: 0000000000020000 RBP: 00007f7e0fc54ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000200000000200 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f7e0fdfa080 R15: 00007ffc29391168 Modules linked in: CR2: 0000000000000000 ---[ end trace 430bbba29a2ab6a9 ]--- RIP: 0010:0x0 Code: Bad RIP value. RSP: 0018:ffff8881f6e09cf0 EFLAGS: 00010202 RAX: ffffffff8150a590 RBX: 0000000000000102 RCX: ffff8881df6aaf40 RDX: 0000000080000102 RSI: 0000000000000000 RDI: ffff8881ebb4f1c0 RBP: ffff8881f6e09d30 R08: 0000000000000004 R09: 0000000000000003 R10: ffffed103edc1398 R11: 1ffff1103edc1398 R12: 00000000ffffb058 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881ebb4f1c0 FS: 00007f7e0e21a6c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 00000001e1135000 CR4: 00000000003406b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 ---------------- Code disassembly (best guess): 0: e8 13 fb da ff call 0xffdafb18 5: 41 f6 c5 01 test $0x1,%r13b 9: 0f 85 95 02 00 00 jne 0x2a4 f: e8 34 f7 da ff call 0xffdaf748 14: 4d 89 f5 mov %r14,%r13 17: 49 8d 7d 34 lea 0x34(%r13),%rdi 1b: be 04 00 00 00 mov $0x4,%esi 20: e8 73 cb 08 00 call 0x8cb98 25: f0 41 ff 45 34 lock incl 0x34(%r13) * 2a: 4c 89 f7 mov %r14,%rdi <-- trapping instruction 2d: 48 83 c7 30 add $0x30,%rdi 31: be 04 00 00 00 mov $0x4,%esi 36: e8 5d cb 08 00 call 0x8cb98 3b: f0 41 ff 46 30 lock incl 0x30(%r14)