================================================================== 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+0x759/0xb60 kernel/time/timer.c:1817 Write of size 8 at addr ffff8881e3b971c8 by task udevd/164 CPU: 0 PID: 164 Comm: udevd 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_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+0x759/0xb60 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:user_access_begin arch/x86/include/asm/uaccess.h:802 [inline] RIP: 0010:strncpy_from_user+0xee/0x310 lib/strncpy_from_user.c:119 Code: 8b 75 d0 4b 8d 5c 35 00 48 89 df 4c 89 ee e8 c9 10 29 ff 48 89 df 4c 89 e6 e8 be 10 29 ff 4c 89 e8 4c 01 f0 0f 82 05 02 00 00 <4c> 39 e0 0f 87 fc 01 00 00 0f 01 cb 0f ae e8 bf 07 00 00 00 4c 89 RSP: 0018:ffff8881ec737d00 EFLAGS: 00000206 ORIG_RAX: ffffffffffffff13 RAX: 0000563c39cec0a0 RBX: 0000563c39cec0a0 RCX: 0000000000000000 RDX: ffff8881ecac8fc0 RSI: 00007ffffffff000 RDI: 0000563c39cec0a0 RBP: ffff8881ec737d40 R08: dffffc0000000000 R09: fffff94000ea3f41 R10: fffff94000ea3f41 R11: 1ffffd4000ea3f40 R12: 00007ffffffff000 R13: 0000000000000fe0 R14: 0000563c39ceb0c0 R15: 0000000000000fe0 getname_flags+0xf4/0x500 fs/namei.c:152 getname+0x19/0x20 fs/namei.c:212 do_sys_open+0x26c/0x5d0 fs/open.c:1117 __do_sys_openat fs/open.c:1150 [inline] __se_sys_openat fs/open.c:1144 [inline] __x64_sys_openat+0xa2/0xb0 fs/open.c:1144 do_syscall_64+0xcf/0x170 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 RIP: 0033:0x7f099a8f9477 Code: 10 00 00 00 44 8b 54 24 e0 48 89 44 24 c0 48 8d 44 24 d0 48 89 44 24 c8 44 89 c2 4c 89 ce bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 76 10 48 8b 15 82 69 0d 00 f7 d8 64 89 02 48 83 RSP: 002b:00007ffd5e5f4aa8 EFLAGS: 00000287 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000563c39d11b60 RCX: 00007f099a8f9477 RDX: 0000000000090800 RSI: 0000563c39ceb0c0 RDI: 00000000ffffff9c RBP: 0000563c39d133f0 R08: 0000000000090800 R09: 0000563c39ceb0c0 R10: 0000000000000000 R11: 0000000000000287 R12: 0000563c39ceb0c0 R13: 0000000000000100 R14: 0000563c2ebcefee R15: 0000000000000000 The buggy address belongs to the page: page:ffffea00078ee5c0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 flags: 0x8000000000000000() raw: 8000000000000000 ffffea0007429608 ffffea00078ee588 0000000000000000 raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as freed page last allocated via order 0, migratetype Unmovable, gfp_mask 0x102cc2(GFP_HIGHUSER|__GFP_NOWARN) 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] pcpu_alloc_pages mm/percpu-vm.c:94 [inline] pcpu_populate_chunk+0x1b6/0xce0 mm/percpu-vm.c:284 pcpu_alloc+0x8ec/0x1120 mm/percpu.c:1714 __alloc_percpu_gfp+0x25/0x30 mm/percpu.c:1783 prealloc_init+0x24b/0x810 kernel/bpf/hashtab.c:154 htab_map_alloc+0x65f/0x940 kernel/bpf/hashtab.c:385 find_and_alloc_map kernel/bpf/syscall.c:122 [inline] map_create+0x2d8/0x980 kernel/bpf/syscall.c:573 __do_sys_bpf kernel/bpf/syscall.c:2873 [inline] __se_sys_bpf+0x2dc/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_pcp_prepare mm/page_alloc.c:1233 [inline] free_unref_page_prepare+0x2a9/0x3a0 mm/page_alloc.c:3085 free_unref_page mm/page_alloc.c:3134 [inline] free_the_page mm/page_alloc.c:4954 [inline] __free_pages+0xaa/0x110 mm/page_alloc.c:4962 pcpu_free_pages mm/percpu-vm.c:64 [inline] pcpu_depopulate_chunk mm/percpu-vm.c:328 [inline] pcpu_balance_workfn+0x8c7/0x14b0 mm/percpu.c:1865 process_one_work+0x73b/0xcc0 kernel/workqueue.c:2290 worker_thread+0xa5c/0x13b0 kernel/workqueue.c:2436 kthread+0x31e/0x3a0 kernel/kthread.c:288 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:354 Memory state around the buggy address: ffff8881e3b97080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8881e3b97100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff8881e3b97180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff8881e3b97200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8881e3b97280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ================================================================== BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor instruction fetch in kernel mode #PF: error_code(0x0010) - not-present page PGD 0 P4D 0 Oops: 0010 [#1] PREEMPT SMP KASAN CPU: 0 PID: 164 Comm: udevd 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: 00010206 RAX: ffffffff8150a590 RBX: 0000000000000100 RCX: ffff8881ecac8fc0 RDX: 0000000000000100 RSI: 0000000000000000 RDI: ffff8881e3b971c0 RBP: ffff8881f6e09d30 R08: 0000000000000004 R09: 0000000000000003 R10: ffffed103edc1398 R11: 1ffff1103edc1398 R12: 00000000ffff9820 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881e3b971c0 FS: 00007f099a7cac80(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 00000001ecb34000 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:user_access_begin arch/x86/include/asm/uaccess.h:802 [inline] RIP: 0010:strncpy_from_user+0xee/0x310 lib/strncpy_from_user.c:119 Code: 8b 75 d0 4b 8d 5c 35 00 48 89 df 4c 89 ee e8 c9 10 29 ff 48 89 df 4c 89 e6 e8 be 10 29 ff 4c 89 e8 4c 01 f0 0f 82 05 02 00 00 <4c> 39 e0 0f 87 fc 01 00 00 0f 01 cb 0f ae e8 bf 07 00 00 00 4c 89 RSP: 0018:ffff8881ec737d00 EFLAGS: 00000206 ORIG_RAX: ffffffffffffff13 RAX: 0000563c39cec0a0 RBX: 0000563c39cec0a0 RCX: 0000000000000000 RDX: ffff8881ecac8fc0 RSI: 00007ffffffff000 RDI: 0000563c39cec0a0 RBP: ffff8881ec737d40 R08: dffffc0000000000 R09: fffff94000ea3f41 R10: fffff94000ea3f41 R11: 1ffffd4000ea3f40 R12: 00007ffffffff000 R13: 0000000000000fe0 R14: 0000563c39ceb0c0 R15: 0000000000000fe0 getname_flags+0xf4/0x500 fs/namei.c:152 getname+0x19/0x20 fs/namei.c:212 do_sys_open+0x26c/0x5d0 fs/open.c:1117 __do_sys_openat fs/open.c:1150 [inline] __se_sys_openat fs/open.c:1144 [inline] __x64_sys_openat+0xa2/0xb0 fs/open.c:1144 do_syscall_64+0xcf/0x170 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 RIP: 0033:0x7f099a8f9477 Code: 10 00 00 00 44 8b 54 24 e0 48 89 44 24 c0 48 8d 44 24 d0 48 89 44 24 c8 44 89 c2 4c 89 ce bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 76 10 48 8b 15 82 69 0d 00 f7 d8 64 89 02 48 83 RSP: 002b:00007ffd5e5f4aa8 EFLAGS: 00000287 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000563c39d11b60 RCX: 00007f099a8f9477 RDX: 0000000000090800 RSI: 0000563c39ceb0c0 RDI: 00000000ffffff9c RBP: 0000563c39d133f0 R08: 0000000000090800 R09: 0000563c39ceb0c0 R10: 0000000000000000 R11: 0000000000000287 R12: 0000563c39ceb0c0 R13: 0000000000000100 R14: 0000563c2ebcefee R15: 0000000000000000 Modules linked in: CR2: 0000000000000000 ---[ end trace 34f9c42dae47367c ]--- RIP: 0010:0x0 Code: Bad RIP value. RSP: 0018:ffff8881f6e09cf0 EFLAGS: 00010206 RAX: ffffffff8150a590 RBX: 0000000000000100 RCX: ffff8881ecac8fc0 RDX: 0000000000000100 RSI: 0000000000000000 RDI: ffff8881e3b971c0 RBP: ffff8881f6e09d30 R08: 0000000000000004 R09: 0000000000000003 R10: ffffed103edc1398 R11: 1ffff1103edc1398 R12: 00000000ffff9820 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881e3b971c0 FS: 00007f099a7cac80(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 00000001ecb34000 CR4: 00000000003406b0 DR0: 0000000000000000 DR1: 0000200000000300 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 ---------------- Code disassembly (best guess): 0: 8b 75 d0 mov -0x30(%rbp),%esi 3: 4b 8d 5c 35 00 lea 0x0(%r13,%r14,1),%rbx 8: 48 89 df mov %rbx,%rdi b: 4c 89 ee mov %r13,%rsi e: e8 c9 10 29 ff call 0xff2910dc 13: 48 89 df mov %rbx,%rdi 16: 4c 89 e6 mov %r12,%rsi 19: e8 be 10 29 ff call 0xff2910dc 1e: 4c 89 e8 mov %r13,%rax 21: 4c 01 f0 add %r14,%rax 24: 0f 82 05 02 00 00 jb 0x22f * 2a: 4c 39 e0 cmp %r12,%rax <-- trapping instruction 2d: 0f 87 fc 01 00 00 ja 0x22f 33: 0f 01 cb stac 36: 0f ae e8 lfence 39: bf 07 00 00 00 mov $0x7,%edi 3e: 4c rex.WR 3f: 89 .byte 0x89