================================================================== BUG: KASAN: use-after-free in hlist_move_list include/linux/list.h:870 [inline] BUG: KASAN: use-after-free in __collect_expired_timers kernel/time/timer.c:1514 [inline] BUG: KASAN: use-after-free in collect_expired_timers kernel/time/timer.c:1749 [inline] BUG: KASAN: use-after-free in __run_timers+0x4f5/0xb60 kernel/time/timer.c:1813 Write of size 8 at addr ffff8881d4ebb1c8 by task syz.4.1531/5679 CPU: 0 PID: 5679 Comm: syz.4.1531 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_move_list include/linux/list.h:870 [inline] __collect_expired_timers kernel/time/timer.c:1514 [inline] collect_expired_timers kernel/time/timer.c:1749 [inline] __run_timers+0x4f5/0xb60 kernel/time/timer.c:1813 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:test_bit include/asm-generic/bitops-instrumented.h:237 [inline] RIP: 0010:PageActive include/linux/page-flags.h:321 [inline] RIP: 0010:mark_page_accessed+0x9d/0x620 mm/swap.c:376 Code: 4d 8b 3e 44 89 fe 83 e6 01 31 ff e8 1d 34 e3 ff 41 f6 c7 01 0f 85 cd 04 00 00 e8 3e 30 e3 ff 4d 89 e7 4c 89 ff be 08 00 00 00 5e 04 11 00 4c 89 f8 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 ff RSP: 0018:ffff8881eb0ef620 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13 RAX: ffffffff817c4ea2 RBX: 1ffffd4000ef0ef9 RCX: ffff8881df25ee40 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffea00077877c0 RBP: ffff8881eb0ef650 R08: dffffc0000000000 R09: ffffed103be4bdc9 R10: ffffed103be4bdc9 R11: 1ffff1103be4bdc8 R12: ffffea00077877c0 R13: dffffc0000000000 R14: ffffea00077877c8 R15: ffffea00077877c0 zap_pte_range mm/memory.c:1102 [inline] zap_pmd_range mm/memory.c:1222 [inline] zap_pud_range mm/memory.c:1251 [inline] zap_p4d_range mm/memory.c:1272 [inline] unmap_page_range+0x105b/0x1b20 mm/memory.c:1293 unmap_single_vma mm/memory.c:1338 [inline] unmap_vmas+0x245/0x340 mm/memory.c:1370 exit_mmap+0x2bb/0x520 mm/mmap.c:3191 __mmput+0x92/0x2e0 kernel/fork.c:1101 mmput+0x47/0x60 kernel/fork.c:1122 exit_mm kernel/exit.c:538 [inline] do_exit+0x99f/0x2660 kernel/exit.c:848 do_group_exit+0x13e/0x300 kernel/exit.c:984 get_signal+0xdee/0x13d0 kernel/signal.c:2738 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: 0033:0x7fe757ce0969 Code: Bad RIP value. RSP: 002b:00007fe756349038 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000003 RBX: 00007fe757f07fa0 RCX: 00007fe757ce0969 RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000200000000700 RBP: 00007fe757d62ab1 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007fe757f07fa0 R15: 00007ffe6f488cb8 The buggy address belongs to the page: page:ffffea000753aec0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 flags: 0x8000000000000000() raw: 8000000000000000 0000000000000000 ffffea000753aec8 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+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] kmalloc_order mm/slab_common.c:1342 [inline] kmalloc_order_trace+0x31/0x100 mm/slab_common.c:1358 kmalloc_large include/linux/slab.h:485 [inline] __kmalloc+0x162/0x2f0 mm/slub.c:3902 __kmalloc_node include/linux/slab.h:422 [inline] kmalloc_node include/linux/slab.h:599 [inline] kvmalloc_node+0x88/0xf0 mm/util.c:596 kvmalloc include/linux/mm.h:761 [inline] kvzalloc include/linux/mm.h:769 [inline] bpf_check+0xfb/0x9cf0 kernel/bpf/verifier.c:9561 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 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: ffff8881d4ebb080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8881d4ebb100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff8881d4ebb180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff8881d4ebb200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8881d4ebb280: 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 1dccbd067 P4D 1dccbd067 PUD 0 Oops: 0010 [#1] PREEMPT SMP KASAN CPU: 0 PID: 5679 Comm: syz.4.1531 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: 0000000000000101 RCX: ffff8881df25ee40 RDX: 0000000000000101 RSI: 0000000000000000 RDI: ffff8881d4ebb1c0 RBP: ffff8881f6e09d30 R08: 0000000000000004 R09: 0000000000000003 R10: ffffed103edc1398 R11: 1ffff1103edc1398 R12: 00000000ffffc9c0 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881d4ebb1c0 FS: 00007fe7563496c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 00000001cc0a5000 CR4: 00000000003406b0 DR0: 0000000000000000 DR1: 0000200000000300 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff3 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:test_bit include/asm-generic/bitops-instrumented.h:237 [inline] RIP: 0010:PageActive include/linux/page-flags.h:321 [inline] RIP: 0010:mark_page_accessed+0x9d/0x620 mm/swap.c:376 Code: 4d 8b 3e 44 89 fe 83 e6 01 31 ff e8 1d 34 e3 ff 41 f6 c7 01 0f 85 cd 04 00 00 e8 3e 30 e3 ff 4d 89 e7 4c 89 ff be 08 00 00 00 5e 04 11 00 4c 89 f8 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 ff RSP: 0018:ffff8881eb0ef620 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13 RAX: ffffffff817c4ea2 RBX: 1ffffd4000ef0ef9 RCX: ffff8881df25ee40 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffea00077877c0 RBP: ffff8881eb0ef650 R08: dffffc0000000000 R09: ffffed103be4bdc9 R10: ffffed103be4bdc9 R11: 1ffff1103be4bdc8 R12: ffffea00077877c0 R13: dffffc0000000000 R14: ffffea00077877c8 R15: ffffea00077877c0 zap_pte_range mm/memory.c:1102 [inline] zap_pmd_range mm/memory.c:1222 [inline] zap_pud_range mm/memory.c:1251 [inline] zap_p4d_range mm/memory.c:1272 [inline] unmap_page_range+0x105b/0x1b20 mm/memory.c:1293 unmap_single_vma mm/memory.c:1338 [inline] unmap_vmas+0x245/0x340 mm/memory.c:1370 exit_mmap+0x2bb/0x520 mm/mmap.c:3191 __mmput+0x92/0x2e0 kernel/fork.c:1101 mmput+0x47/0x60 kernel/fork.c:1122 exit_mm kernel/exit.c:538 [inline] do_exit+0x99f/0x2660 kernel/exit.c:848 do_group_exit+0x13e/0x300 kernel/exit.c:984 get_signal+0xdee/0x13d0 kernel/signal.c:2738 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: 0033:0x7fe757ce0969 Code: Bad RIP value. RSP: 002b:00007fe756349038 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000003 RBX: 00007fe757f07fa0 RCX: 00007fe757ce0969 RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000200000000700 RBP: 00007fe757d62ab1 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007fe757f07fa0 R15: 00007ffe6f488cb8 Modules linked in: CR2: 0000000000000000 ---[ end trace 15ea854926c208dc ]--- RIP: 0010:0x0 Code: Bad RIP value. RSP: 0018:ffff8881f6e09cf0 EFLAGS: 00010202 RAX: ffffffff8150a590 RBX: 0000000000000101 RCX: ffff8881df25ee40 RDX: 0000000000000101 RSI: 0000000000000000 RDI: ffff8881d4ebb1c0 RBP: ffff8881f6e09d30 R08: 0000000000000004 R09: 0000000000000003 R10: ffffed103edc1398 R11: 1ffff1103edc1398 R12: 00000000ffffc9c0 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881d4ebb1c0 FS: 00007fe7563496c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 00000001cc0a5000 CR4: 00000000003406b0 DR0: 0000000000000000 DR1: 0000200000000300 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff3 DR7: 0000000000000600 ---------------- Code disassembly (best guess): 0: 4d 8b 3e mov (%r14),%r15 3: 44 89 fe mov %r15d,%esi 6: 83 e6 01 and $0x1,%esi 9: 31 ff xor %edi,%edi b: e8 1d 34 e3 ff call 0xffe3342d 10: 41 f6 c7 01 test $0x1,%r15b 14: 0f 85 cd 04 00 00 jne 0x4e7 1a: e8 3e 30 e3 ff call 0xffe3305d 1f: 4d 89 e7 mov %r12,%r15 22: 4c 89 ff mov %r15,%rdi 25: be 08 00 00 00 mov $0x8,%esi * 2a: e8 5e 04 11 00 call 0x11048d <-- trapping instruction 2f: 4c 89 f8 mov %r15,%rax 32: 48 c1 e8 03 shr $0x3,%rax 36: 42 80 3c 28 00 cmpb $0x0,(%rax,%r13,1) 3b: 74 08 je 0x45 3d: 4c 89 ff mov %r15,%rdi