================================================================== BUG: KASAN: use-after-free in hlist_add_head include/linux/list.h:814 [inline] BUG: KASAN: use-after-free in enqueue_timer+0x9e/0x2c0 kernel/time/timer.c:541 Write of size 8 at addr ffff8881e1f6f1c8 by task syz.7.1442/4624 CPU: 1 PID: 4624 Comm: syz.7.1442 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:preempt_schedule_irq+0x96/0x110 kernel/sched/core.c:4560 Code: 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 74 0b 0f 0b 48 f7 03 08 00 00 00 74 4d bf 01 00 00 00 e8 90 21 17 fd fb bf 01 00 00 00 b5 e7 ff ff fa bf 01 00 00 00 e8 2a 23 17 fd 65 48 8b 1d 32 3c RSP: 0018:ffff8881e8f57700 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: 1ffff1103e61eb07 RBX: 0000000000000000 RCX: ffffffff86542900 RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000001 RBP: ffff8881e8f57788 R08: dffffc0000000000 R09: ffffed103edeaf6d R10: ffffed103edeaf6d R11: 1ffff1103edeaf6c R12: 0000000000000000 R13: 0000000000000000 R14: dffffc0000000000 R15: 1ffff1103d1eaee0 retint_kernel+0x1b/0x1b RIP: 0010:dump_stack+0x180/0x1b8 lib/dump_stack.c:124 Code: e8 5d 00 00 00 48 c7 c7 e0 65 28 86 be 04 00 00 00 e8 8c 72 63 fd c7 05 32 85 fe 01 ff ff ff ff 4c 89 6c 24 10 ff 74 24 10 9d <48> c7 44 24 20 0e 36 e0 45 4b c7 04 27 00 00 00 00 65 48 8b 04 25 RSP: 0018:ffff8881e8f57840 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff02 RAX: 4b623c2cd7347e01 RBX: 0000000000000001 RCX: ffffffff8429e0a4 RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffffff862865e0 RBP: ffff8881e8f578f0 R08: 0000000000000004 R09: 0000000000000003 R10: fffffbfff0c50cbc R11: 1ffffffff0c50cbc R12: dffffc0000000000 R13: 0000000000000293 R14: 00000000ffffffff R15: 1ffff1103d1eaf0c fail_dump lib/fault-inject.c:52 [inline] should_fail+0x69e/0x7e0 lib/fault-inject.c:144 __should_failslab+0x10c/0x150 mm/failslab.c:33 should_failslab+0x9/0x20 mm/slab_common.c:1836 slab_pre_alloc_hook mm/slab.h:567 [inline] slab_alloc_node mm/slub.c:2742 [inline] slab_alloc mm/slub.c:2837 [inline] kmem_cache_alloc_trace+0x2d/0x290 mm/slub.c:2854 kmem_cache_alloc_node_trace include/linux/slab.h:444 [inline] kmalloc_node include/linux/slab.h:594 [inline] kzalloc_node include/linux/slab.h:701 [inline] __get_vm_area_node+0x181/0x330 mm/vmalloc.c:2059 __vmalloc_node_range+0xe9/0x6e0 mm/vmalloc.c:2494 __vmalloc_node mm/vmalloc.c:2554 [inline] __vmalloc+0x45/0x50 mm/vmalloc.c:2560 bpf_prog_alloc_no_stats+0x73/0x230 kernel/bpf/core.c:88 bpf_prog_alloc+0x21/0x1f0 kernel/bpf/core.c:114 bpf_prog_load+0x5f4/0xe10 kernel/bpf/syscall.c:1678 __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: 0033:0x7f924a50e969 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:00007f9248b77038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f924a735fa0 RCX: 00007f924a50e969 RDX: 0000000000000048 RSI: 000020000000e000 RDI: 0000000000000005 RBP: 00007f9248b77090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 0000000000000000 R14: 00007f924a735fa0 R15: 00007ffe2ba6c998 Allocated by task 4596: 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 kmem_cache_alloc_trace+0x112/0x290 mm/slub.c:2856 kmalloc include/linux/slab.h:556 [inline] kzalloc include/linux/slab.h:690 [inline] bpf_prog_alloc_no_stats+0xd2/0x230 kernel/bpf/core.c:92 bpf_prog_alloc+0x21/0x1f0 kernel/bpf/core.c:114 bpf_prog_load+0x5f4/0xe10 kernel/bpf/syscall.c:1678 __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 3677: 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 __bpf_prog_free kernel/bpf/core.c:262 [inline] bpf_prog_unlock_free include/linux/filter.h:902 [inline] bpf_jit_free+0x18b/0x1f0 kernel/bpf/core.c:873 bpf_prog_free_deferred+0x2f3/0x370 kernel/bpf/core.c:2042 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 The buggy address belongs to the object at ffff8881e1f6f000 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 456 bytes inside of 512-byte region [ffff8881e1f6f000, ffff8881e1f6f200) The buggy address belongs to the page: page:ffffea000787db00 refcount:1 mapcount:0 mapping:ffff8881f5c02500 index:0x0 compound_mapcount: 0 flags: 0x8000000000010200(slab|head) raw: 8000000000010200 dead000000000100 dead000000000122 ffff8881f5c02500 raw: 0000000000000000 0000000000100010 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+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] kmem_cache_alloc_trace+0x130/0x290 mm/slub.c:2854 kmalloc include/linux/slab.h:556 [inline] kzalloc include/linux/slab.h:690 [inline] bpf_prog_alloc_no_stats+0xd2/0x230 kernel/bpf/core.c:92 bpf_prog_alloc+0x21/0x1f0 kernel/bpf/core.c:114 bpf_prog_load+0x5f4/0xe10 kernel/bpf/syscall.c:1678 __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 bpf_check+0x8371/0x9cf0 kernel/bpf/verifier.c:9731 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 Memory state around the buggy address: ffff8881e1f6f080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881e1f6f100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8881e1f6f180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8881e1f6f200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8881e1f6f280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor instruction fetch in kernel mode #PF: error_code(0x0010) - not-present page PGD 1ed584067 P4D 1ed584067 PUD 0 Oops: 0010 [#1] PREEMPT SMP KASAN CPU: 1 PID: 4624 Comm: syz.7.1442 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:ffff8881f6f09cf0 EFLAGS: 00010202 RAX: ffffffff8150a590 RBX: 0000000000000101 RCX: ffff8881f30f4ec0 RDX: 0000000000000101 RSI: 0000000000000000 RDI: ffff8881e1f6f1c0 RBP: ffff8881f6f09d30 R08: 0000000000000004 R09: 0000000000000003 R10: ffffed103ede1398 R11: 1ffff1103ede1398 R12: 00000000ffffdd40 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881e1f6f1c0 FS: 00007f9248b776c0(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 00000001de990000 CR4: 00000000003406a0 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:native_restore_fl arch/x86/include/asm/irqflags.h:41 [inline] RIP: 0010:arch_local_irq_restore arch/x86/include/asm/irqflags.h:84 [inline] RIP: 0010:console_unlock+0x9ea/0xe80 kernel/printk/printk.c:2527 Code: 64 56 86 e8 48 73 e1 02 f6 c3 01 48 8b 5c 24 28 0f 85 61 04 00 00 e8 55 f9 15 00 e8 80 5a 00 00 48 89 5c 24 70 ff 74 24 70 9d d0 f7 ff ff e8 3c f9 15 00 48 c7 05 d1 d7 0c 05 00 00 00 00 e9 RSP: 0018:ffff8881e8f57520 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13 RAX: ffffffff8149e019 RBX: 0000000000000293 RCX: ffff8881f30f4ec0 RDX: 0000000000000000 RSI: 0000000000000004 RDI: 00000000ffffffff RBP: ffff8881e8f576d0 R08: 0000000000000004 R09: 0000000000000003 R10: ffffed103d1eae94 R11: 1ffff1103d1eae94 R12: 0000000000000000 R13: ffffffff85eefb30 R14: ffffffff8267bbc0 R15: dffffc0000000000 vprintk_emit+0x1be/0x380 kernel/printk/printk.c:2032 vprintk_default+0x28/0x30 kernel/printk/printk.c:2059 vprintk_func+0x19a/0x1e0 kernel/printk/printk_safe.c:393 printk+0xcc/0x110 kernel/printk/printk.c:2092 show_mem+0x2d7/0x2e2 lib/show_mem.c:39 warn_alloc_show_mem mm/page_alloc.c:3843 [inline] warn_alloc+0x2d7/0x300 mm/page_alloc.c:3868 __vmalloc_node_range+0x28e/0x6e0 mm/vmalloc.c:2515 __vmalloc_node mm/vmalloc.c:2554 [inline] __vmalloc+0x45/0x50 mm/vmalloc.c:2560 bpf_prog_alloc_no_stats+0x73/0x230 kernel/bpf/core.c:88 bpf_prog_alloc+0x21/0x1f0 kernel/bpf/core.c:114 bpf_prog_load+0x5f4/0xe10 kernel/bpf/syscall.c:1678 __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: 0033:0x7f924a50e969 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:00007f9248b77038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f924a735fa0 RCX: 00007f924a50e969 RDX: 0000000000000048 RSI: 000020000000e000 RDI: 0000000000000005 RBP: 00007f9248b77090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 0000000000000000 R14: 00007f924a735fa0 R15: 00007ffe2ba6c998 Modules linked in: CR2: 0000000000000000 ---[ end trace 767648891962cb86 ]--- RIP: 0010:0x0 Code: Bad RIP value. RSP: 0018:ffff8881f6f09cf0 EFLAGS: 00010202 RAX: ffffffff8150a590 RBX: 0000000000000101 RCX: ffff8881f30f4ec0 RDX: 0000000000000101 RSI: 0000000000000000 RDI: ffff8881e1f6f1c0 RBP: ffff8881f6f09d30 R08: 0000000000000004 R09: 0000000000000003 R10: ffffed103ede1398 R11: 1ffff1103ede1398 R12: 00000000ffffdd40 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881e1f6f1c0 FS: 00007f9248b776c0(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 00000001de990000 CR4: 00000000003406a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 ---------------- Code disassembly (best guess): 0: 00 00 add %al,(%rax) 2: 00 9c 8f 44 24 20 f6 add %bl,-0x9dfdbbc(%rdi,%rcx,4) 9: 44 24 21 rex.R and $0x21,%al c: 02 74 0b 0f add 0xf(%rbx,%rcx,1),%dh 10: 0b 48 f7 or -0x9(%rax),%ecx 13: 03 08 add (%rax),%ecx 15: 00 00 add %al,(%rax) 17: 00 74 4d bf add %dh,-0x41(%rbp,%rcx,2) 1b: 01 00 add %eax,(%rax) 1d: 00 00 add %al,(%rax) 1f: e8 90 21 17 fd call 0xfd1721b4 24: fb sti 25: bf 01 00 00 00 mov $0x1,%edi * 2a: e8 b5 e7 ff ff call 0xffffe7e4 <-- trapping instruction 2f: fa cli 30: bf 01 00 00 00 mov $0x1,%edi 35: e8 2a 23 17 fd call 0xfd172364 3a: 65 gs 3b: 48 rex.W 3c: 8b .byte 0x8b 3d: 1d .byte 0x1d 3e: 32 .byte 0x32 3f: 3c .byte 0x3c