================================================================== BUG: KASAN: use-after-free in hlist_add_head include/linux/list.h:814 [inline] BUG: KASAN: use-after-free in enqueue_timer+0xb7/0x300 kernel/time/timer.c:541 Write of size 8 at addr ffff8881d0ca31c8 by task syz.4.436/2495 CPU: 0 PID: 2495 Comm: syz.4.436 Not tainted 5.4.289-syzkaller-00011-g39762b7a60e9 #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_add_head include/linux/list.h:814 [inline] enqueue_timer+0xb7/0x300 kernel/time/timer.c:541 __internal_add_timer kernel/time/timer.c:554 [inline] internal_add_timer+0x240/0x430 kernel/time/timer.c:604 __mod_timer+0x6f1/0x13e0 kernel/time/timer.c:1065 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:__sanitizer_cov_trace_pc+0x4/0x50 kernel/kcov.c:186 Code: 00 00 00 0f 1f 00 be 0c 00 00 00 48 c7 c7 20 b1 f1 85 e8 5f e3 2f 00 c3 90 90 90 90 90 90 90 90 90 90 90 90 90 90 48 8b 04 24 <65> 48 8b 0d 04 43 9e 7e 65 8b 15 09 43 9e 7e f7 c2 00 01 1f 00 74 RSP: 0018:ffff8881cfdcf080 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 RAX: ffffffff8153c435 RBX: ffff8881cfdcf1c0 RCX: 99348ddefba83700 RDX: 0000000000000000 RSI: ffffffff84509dfe RDI: ffff8881cfdcf1c0 RBP: ffff8881cfdcf170 R08: dffffc0000000000 R09: ffff8881cfdcf130 R10: 0000000000000000 R11: dffffc0000000001 R12: ffff8881d1514ec0 R13: ffffffff8153c410 R14: dffffc0000000000 R15: 0000000000000000 stack_trace_consume_entry+0x25/0x240 kernel/stacktrace.c:83 arch_stack_walk+0x105/0x140 arch/x86/kernel/stacktrace.c:27 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] kmem_cache_alloc+0xd9/0x250 mm/slub.c:2842 kmem_cache_zalloc include/linux/slab.h:680 [inline] __kernfs_new_node+0xdb/0x6e0 fs/kernfs/dir.c:639 kernfs_new_node+0x130/0x230 fs/kernfs/dir.c:717 kernfs_create_dir_ns+0x3f/0x120 fs/kernfs/dir.c:1041 sysfs_create_dir_ns+0x185/0x390 fs/sysfs/dir.c:59 create_dir lib/kobject.c:89 [inline] kobject_add_internal+0x6b7/0xca0 lib/kobject.c:263 kobject_add_varg lib/kobject.c:398 [inline] kobject_add+0x14e/0x210 lib/kobject.c:450 device_add+0x3eb/0xbb0 drivers/base/core.c:2844 netdev_register_kobject+0x176/0x310 net/core/net-sysfs.c:1854 register_netdevice+0xbc5/0x12a0 net/core/dev.c:9209 tun_set_iff+0x7f7/0xdc0 drivers/net/tun.c:2922 __tun_chr_ioctl+0x8a9/0x1d00 drivers/net/tun.c:3187 do_vfs_ioctl+0x742/0x1720 fs/ioctl.c:47 ksys_ioctl fs/ioctl.c:742 [inline] __do_sys_ioctl fs/ioctl.c:749 [inline] __se_sys_ioctl fs/ioctl.c:747 [inline] __x64_sys_ioctl+0xd4/0x110 fs/ioctl.c:747 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 RIP: 0033:0x7f2f3cbc6de9 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:00007f2f3c639038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f2f3cddffa0 RCX: 00007f2f3cbc6de9 RDX: 0000400000000200 RSI: 00000000400454ca RDI: 0000000000000003 RBP: 00007f2f3cc482a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f2f3cddffa0 R15: 00007fff9513e618 The buggy address belongs to the page: page:ffffea00074328c0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 flags: 0x8000000000000000() raw: 8000000000000000 0000000000000000 dead000000000122 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 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+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_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+0x2a/0x100 mm/slab_common.c:1358 __kmalloc_node include/linux/slab.h:422 [inline] kmalloc_node include/linux/slab.h:599 [inline] bpf_map_area_alloc+0x47/0x90 kernel/bpf/syscall.c:149 prealloc_init+0x12f/0x800 kernel/bpf/hashtab.c:142 htab_map_alloc+0x638/0x930 kernel/bpf/hashtab.c:385 find_and_alloc_map kernel/bpf/syscall.c:122 [inline] map_create kernel/bpf/syscall.c:573 [inline] __do_sys_bpf kernel/bpf/syscall.c:2873 [inline] __se_sys_bpf+0x3291/0xbcb0 kernel/bpf/syscall.c:2849 do_syscall_64+0xca/0x1c0 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+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 htab_free_elems kernel/bpf/hashtab.c:116 [inline] prealloc_destroy kernel/bpf/hashtab.c:194 [inline] htab_map_free+0x515/0x670 kernel/bpf/hashtab.c:1238 bpf_map_free_deferred+0xa8/0x100 kernel/bpf/syscall.c:311 process_one_work+0x765/0xd20 kernel/workqueue.c:2290 worker_thread+0xaef/0x1470 kernel/workqueue.c:2436 kthread+0x2da/0x360 kernel/kthread.c:288 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:354 Memory state around the buggy address: ffff8881d0ca3080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8881d0ca3100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff8881d0ca3180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff8881d0ca3200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8881d0ca3280: 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: 10 Comm: ksoftirqd/0 Tainted: G B 5.4.289-syzkaller-00011-g39762b7a60e9 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 RIP: 0010:0x0 Code: Bad RIP value. RSP: 0018:ffff8881f5dd7b58 EFLAGS: 00010206 RAX: ffffffff8154e8aa RBX: 0000000000000100 RCX: ffff8881f5dc5e80 RDX: 0000000080000100 RSI: 0000000000000000 RDI: ffff8881d0ca31c0 RBP: ffff8881f5dd7d08 R08: ffffffff8154e4ee R09: 0000000000000003 R10: ffffffffffffffff R11: dffffc0000000001 R12: 00000001000041a8 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881d0ca31c0 FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 00000001ecd55000 CR4: 00000000003406b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 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 run_ksoftirqd+0x1f/0x30 kernel/softirq.c:603 smpboot_thread_fn+0x545/0x930 kernel/smpboot.c:165 kthread+0x2da/0x360 kernel/kthread.c:288 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:354 Modules linked in: CR2: 0000000000000000 ---[ end trace c897a7704e21b563 ]--- RIP: 0010:0x0 Code: Bad RIP value. RSP: 0018:ffff8881f5dd7b58 EFLAGS: 00010206 RAX: ffffffff8154e8aa RBX: 0000000000000100 RCX: ffff8881f5dc5e80 RDX: 0000000080000100 RSI: 0000000000000000 RDI: ffff8881d0ca31c0 RBP: ffff8881f5dd7d08 R08: ffffffff8154e4ee R09: 0000000000000003 R10: ffffffffffffffff R11: dffffc0000000001 R12: 00000001000041a8 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881d0ca31c0 FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 00000001ecd55000 CR4: 00000000003406b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess), 1 bytes skipped: 0: 00 00 add %al,(%rax) 2: 0f 1f 00 nopl (%rax) 5: be 0c 00 00 00 mov $0xc,%esi a: 48 c7 c7 20 b1 f1 85 mov $0xffffffff85f1b120,%rdi 11: e8 5f e3 2f 00 call 0x2fe375 16: c3 ret 17: 90 nop 18: 90 nop 19: 90 nop 1a: 90 nop 1b: 90 nop 1c: 90 nop 1d: 90 nop 1e: 90 nop 1f: 90 nop 20: 90 nop 21: 90 nop 22: 90 nop 23: 90 nop 24: 90 nop 25: 48 8b 04 24 mov (%rsp),%rax * 29: 65 48 8b 0d 04 43 9e mov %gs:0x7e9e4304(%rip),%rcx # 0x7e9e4335 <-- trapping instruction 30: 7e 31: 65 8b 15 09 43 9e 7e mov %gs:0x7e9e4309(%rip),%edx # 0x7e9e4341 38: f7 c2 00 01 1f 00 test $0x1f0100,%edx 3e: 74 .byte 0x74