================================================================== 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 ffff8881d76931c8 by task udevd/162 CPU: 0 PID: 162 Comm: udevd Not tainted 5.4.274-syzkaller-00002-g6f97bd951d82 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 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:538 [inline] smp_apic_timer_interrupt+0x11a/0x460 arch/x86/kernel/apic/apic.c:1149 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 a0 a7 f1 85 e8 3f de 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 54 51 9e 7e 65 8b 15 59 51 9e 7e f7 c2 00 01 1f 00 74 RSP: 0018:ffff8881ec96f6e0 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: ffffffff8153b3f2 RBX: ffff8881ec96f820 RCX: 0000000000000000 RDX: ffff8881ec96f82c RSI: 0000000000000000 RDI: 0000000000000000 RBP: 1ffff1103d92df05 R08: ffffffff8153b3af R09: ffff8881ec96f790 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff1103d92df05 R13: 0000000000000004 R14: 0000000000000000 R15: 1ffff1103d92df06 stack_trace_consume_entry+0xe2/0x240 kernel/stacktrace.c:93 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 __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] seq_buf_alloc fs/seq_file.c:35 [inline] seq_read+0x23c/0xe60 fs/seq_file.c:207 __vfs_read+0x103/0x730 fs/read_write.c:425 vfs_read+0x148/0x360 fs/read_write.c:461 ksys_read+0x199/0x2c0 fs/read_write.c:587 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 RIP: 0033:0x7f974ec55b6a Code: 00 3d 00 00 41 00 75 0d 50 48 8d 3d 2d 08 0a 00 e8 ea 7d 01 00 31 c0 e9 07 ff ff ff 64 8b 04 25 18 00 00 00 85 c0 75 1b 0f 05 <48> 3d 00 f0 ff ff 76 6c 48 8b 15 8f a2 0d 00 f7 d8 64 89 02 48 83 RSP: 002b:00007ffcbf21c188 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 000055bdb49c5860 RCX: 00007f974ec55b6a RDX: 0000000000001000 RSI: 000055bdb49fb300 RDI: 000000000000000c RBP: 000055bdb49c5860 R08: 000000000000000c R09: 0000000000000000 R10: 000000000000010f R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000003fff R14: 00007ffcbf21c668 R15: 000000000000000a The buggy address belongs to the page: page:ffffea00075da4c0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 flags: 0x8000000000000000() raw: 8000000000000000 ffffea0007bdcb08 ffffea00075b7f88 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+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] pcpu_alloc_pages mm/percpu-vm.c:94 [inline] pcpu_populate_chunk+0x1bb/0xd00 mm/percpu-vm.c:284 pcpu_alloc+0x79e/0x1050 mm/percpu.c:1714 prealloc_init+0x238/0x800 kernel/bpf/hashtab.c:154 htab_map_alloc+0x638/0x930 kernel/bpf/hashtab.c:382 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_pcp_prepare mm/page_alloc.c:1233 [inline] free_unref_page_prepare+0x297/0x380 mm/page_alloc.c:3085 free_unref_page mm/page_alloc.c:3134 [inline] free_the_page mm/page_alloc.c:4953 [inline] __free_pages+0xaf/0x140 mm/page_alloc.c:4961 pcpu_free_pages mm/percpu-vm.c:64 [inline] pcpu_depopulate_chunk mm/percpu-vm.c:328 [inline] pcpu_balance_workfn+0x940/0x1450 mm/percpu.c:1865 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: ffff8881d7693080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8881d7693100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff8881d7693180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff8881d7693200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8881d7693280: 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: 347 Comm: syz-fuzzer Tainted: G B 5.4.274-syzkaller-00002-g6f97bd951d82 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 RIP: 0010:0x0 Code: Bad RIP value. RSP: 0018:ffff8881f6e09d18 EFLAGS: 00010206 RAX: ffffffff8154d7aa RBX: 0000000000000100 RCX: ffff8881dd648000 RDX: 0000000000000100 RSI: 0000000000000000 RDI: ffff8881d76931c0 RBP: ffff8881f6e09ec8 R08: ffffffff8154d3ee R09: 0000000000000003 R10: ffffffffffffffff R11: dffffc0000000001 R12: 00000000ffffd0c8 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881d76931c0 FS: 000000c000058090(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 0000000005e0e000 CR4: 00000000003406b0 DR0: 0000000000000000 DR1: 0000000000000000 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:538 [inline] smp_apic_timer_interrupt+0x11a/0x460 arch/x86/kernel/apic/apic.c:1149 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:834 RIP: 0010:stack_trace_consume_entry+0x172/0x240 kernel/stacktrace.c:95 Code: 04 34 84 c0 0f 85 c2 00 00 00 48 8b 44 24 08 8b 28 89 df 89 ee e8 de 88 10 00 39 eb 0f 92 c0 48 83 c4 20 5b 41 5c 41 5d 41 5e <41> 5f 5d c3 89 e9 80 e1 07 80 c1 03 38 c1 0f 8c b7 fe ff ff 48 89 RSP: 0018:ffff8881dd126fc8 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13 RAX: ffff8881dd127001 RBX: ffff8881dd126fe0 RCX: ffff8881dd648000 RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000000000000 RBP: 1ffff1103ba24e19 R08: ffffffff8153b3af R09: ffff8881dd127030 R10: 0000000000000000 R11: dffffc0000000001 R12: ffff8881dd648000 R13: ffffffff8153b310 R14: ffff8881dd1270c0 R15: 1ffff1103ba24e1a arch_stack_walk+0x105/0x140 arch/x86/kernel/stacktrace.c:27 stack_trace_save+0x118/0x1c0 kernel/stacktrace.c:123 save_stack+0x95/0x880 mm/page_owner.c:122 __reset_page_owner+0x1f/0x100 mm/page_owner.c:149 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+0x297/0x380 mm/page_alloc.c:3085 free_unref_page_list+0x10a/0x590 mm/page_alloc.c:3154 release_pages+0xad8/0xb20 mm/swap.c:842 tlb_batch_pages_flush mm/mmu_gather.c:49 [inline] tlb_flush_mmu_free mm/mmu_gather.c:189 [inline] tlb_flush_mmu+0xc8/0x170 mm/mmu_gather.c:196 zap_pte_range mm/memory.c:1173 [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+0x1d29/0x2620 mm/memory.c:1293 unmap_single_vma mm/memory.c:1338 [inline] unmap_vmas+0x355/0x4b0 mm/memory.c:1370 exit_mmap+0x2bc/0x520 mm/mmap.c:3191 __mmput+0x8e/0x2c0 kernel/fork.c:1101 exit_mm kernel/exit.c:536 [inline] do_exit+0xc08/0x2bc0 kernel/exit.c:846 do_group_exit+0x138/0x300 kernel/exit.c:982 get_signal+0xdb1/0x1440 kernel/signal.c:2735 do_signal+0xb0/0x11f0 arch/x86/kernel/signal.c:809 exit_to_usermode_loop+0xc0/0x1a0 arch/x86/entry/common.c:159 prepare_exit_to_usermode+0x199/0x200 arch/x86/entry/common.c:194 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 RIP: 0033:0x473523 Code: Bad RIP value. RSP: 002b:000000c000069e80 EFLAGS: 00000202 ORIG_RAX: 00000000000000ca RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000473523 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00000000025c2800 RBP: 000000c000069ec8 R08: 0000000000000000 R09: 0000000000000000 R10: 000000c000069eb8 R11: 0000000000000202 R12: 000000c000069eb8 R13: 000000c000e4a400 R14: 000000c0000064e0 R15: 0000000000000005 Modules linked in: CR2: 0000000000000000 ---[ end trace e0228287e6ba1c43 ]--- RIP: 0010:0x0 Code: Bad RIP value. RSP: 0018:ffff8881f6e09d18 EFLAGS: 00010206 RAX: ffffffff8154d7aa RBX: 0000000000000100 RCX: ffff8881dd648000 RDX: 0000000000000100 RSI: 0000000000000000 RDI: ffff8881d76931c0 RBP: ffff8881f6e09ec8 R08: ffffffff8154d3ee R09: 0000000000000003 R10: ffffffffffffffff R11: dffffc0000000001 R12: 00000000ffffd0c8 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881d76931c0 FS: 000000c000058090(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 0000000005e0e000 CR4: 00000000003406b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 ---------------- 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 a0 a7 f1 85 mov $0xffffffff85f1a7a0,%rdi 11: e8 3f de 2f 00 call 0x2fde55 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 54 51 9e mov %gs:0x7e9e5154(%rip),%rcx # 0x7e9e5185 <-- trapping instruction 30: 7e 31: 65 8b 15 59 51 9e 7e mov %gs:0x7e9e5159(%rip),%edx # 0x7e9e5191 38: f7 c2 00 01 1f 00 test $0x1f0100,%edx 3e: 74 .byte 0x74