================================================================== 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 ffff8881eede31c8 by task kworker/0:6/432 CPU: 0 PID: 432 Comm: kworker/0:6 Not tainted 5.4.290-syzkaller-00017-g6b07fcd94a6a #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: rcu_gp process_srcu 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:__sanitizer_cov_trace_pc+0x0/0x50 kernel/kcov.c:183 Code: 1f 84 00 00 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 74 42 9e 7e 65 8b 15 79 42 9e 7e f7 c2 00 RSP: 0018:ffff8881eadc7b18 EFLAGS: 00000202 ORIG_RAX: ffffffffffffff13 RAX: ffff8881eb083f00 RBX: 0000003e0277d57e RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffff8881eadc7bd8 R08: ffffffff8231cd01 R09: ffffed103d5b8f81 R10: 0000000000000000 R11: dffffc0000000001 R12: ffffffff84fa5520 R13: 1ffff1103d5b8f68 R14: 0000000000000001 R15: ffffffff84fa5560 check_preemption_disabled+0x9f/0x320 lib/smp_processor_id.c:16 delay_tsc+0x67/0xd0 arch/x86/lib/delay.c:79 try_check_zero+0x2f2/0x360 kernel/rcu/srcutree.c:708 srcu_advance_state kernel/rcu/srcutree.c:1146 [inline] process_srcu+0x1ab/0xc40 kernel/rcu/srcutree.c:1241 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 The buggy address belongs to the page: page:ffffea0007bb78c0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 flags: 0x8000000000000000() raw: 8000000000000000 0000000000000000 ffffea0007bb78c8 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] kvmalloc_node+0x7e/0xf0 mm/util.c:596 kvmalloc include/linux/mm.h:761 [inline] kvzalloc include/linux/mm.h:769 [inline] bpf_check+0xf4/0xb3e0 kernel/bpf/verifier.c:9561 bpf_prog_load kernel/bpf/syscall.c:1724 [inline] __do_sys_bpf kernel/bpf/syscall.c:2891 [inline] __se_sys_bpf+0x8139/0xbcb0 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 bpf_check+0x8aeb/0xb3e0 kernel/bpf/verifier.c:9731 bpf_prog_load kernel/bpf/syscall.c:1724 [inline] __do_sys_bpf kernel/bpf/syscall.c:2891 [inline] __se_sys_bpf+0x8139/0xbcb0 kernel/bpf/syscall.c:2849 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 Memory state around the buggy address: ffff8881eede3080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8881eede3100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff8881eede3180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff8881eede3200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8881eede3280: 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: 0 Comm: swapper/0 Tainted: G B 5.4.290-syzkaller-00017-g6b07fcd94a6a #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:0x0 Code: Bad RIP value. RSP: 0018:ffff8881f6e09d18 EFLAGS: 00010202 RAX: ffffffff8154e8ca RBX: 0000000000000101 RCX: ffffffff85e1adc0 RDX: 0000000080000101 RSI: 0000000000000000 RDI: ffff8881eede31c0 RBP: ffff8881f6e09ec8 R08: ffffffff8154e50e R09: 0000000000000003 R10: ffffffffffffffff R11: dffffc0000000001 R12: 00000000ffffb8f0 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881eede31c0 FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 00000001f18ee000 CR4: 00000000003406b0 DR0: 0000000000000000 DR1: 0040000100000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 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 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:default_idle+0x1f/0x30 arch/x86/kernel/process.c:573 Code: 90 90 90 90 90 90 90 90 90 90 90 e8 db b0 da fd bf 01 00 00 00 89 c6 e8 3f 95 d1 fc 0f 1f 44 00 00 0f 00 2d 73 a4 4d 00 fb f4 bc b0 da fd bf ff ff ff ff 89 c6 e9 20 95 d1 fc 41 57 41 56 53 RSP: 0018:ffffffff85e07d18 EFLAGS: 000002d2 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000000 RBX: dffffc0000000000 RCX: ffffffff85e1adc0 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001 RBP: ffffffff85e07e20 R08: ffffffff8231cd01 R09: fffffbfff0bc35b9 R10: 0000000000000000 R11: dffffc0000000001 R12: ffffffff864c4d28 R13: ffffffff85e1adc0 R14: 1ffffffff0bc35b8 R15: 0000000000000000 default_idle_call kernel/sched/idle.c:94 [inline] cpuidle_idle_call kernel/sched/idle.c:154 [inline] do_idle+0x248/0x660 kernel/sched/idle.c:264 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:356 start_kernel+0x6d9/0x81d init/main.c:1036 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:241 Modules linked in: CR2: 0000000000000000 ---[ end trace c2721911c65701d1 ]--- RIP: 0010:0x0 Code: Bad RIP value. RSP: 0018:ffff8881f6e09d18 EFLAGS: 00010202 RAX: ffffffff8154e8ca RBX: 0000000000000101 RCX: ffffffff85e1adc0 RDX: 0000000080000101 RSI: 0000000000000000 RDI: ffff8881eede31c0 RBP: ffff8881f6e09ec8 R08: ffffffff8154e50e R09: 0000000000000003 R10: ffffffffffffffff R11: dffffc0000000001 R12: 00000000ffffb8f0 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881eede31c0 FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 00000001f18ee000 CR4: 00000000003406b0 DR0: 0000000000000000 DR1: 0040000100000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 ---------------- Code disassembly (best guess), 1 bytes skipped: 0: 84 00 test %al,(%rax) 2: 00 00 add %al,(%rax) 4: 00 00 add %al,(%rax) 6: 0f 1f 00 nopl (%rax) 9: be 0c 00 00 00 mov $0xc,%esi e: 48 c7 c7 20 b1 f1 85 mov $0xffffffff85f1b120,%rdi 15: e8 5f e3 2f 00 call 0x2fe379 1a: c3 ret 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: 90 nop 26: 90 nop 27: 90 nop 28: 90 nop * 29: 48 8b 04 24 mov (%rsp),%rax <-- trapping instruction 2d: 65 48 8b 0d 74 42 9e mov %gs:0x7e9e4274(%rip),%rcx # 0x7e9e42a9 34: 7e 35: 65 8b 15 79 42 9e 7e mov %gs:0x7e9e4279(%rip),%edx # 0x7e9e42b5 3c: f7 .byte 0xf7 3d: c2 .byte 0xc2