================================================================== BUG: KASAN: use-after-free in __hlist_del include/linux/list.h:791 [inline] BUG: KASAN: use-after-free in detach_timer kernel/time/timer.c:824 [inline] BUG: KASAN: use-after-free in expire_timers kernel/time/timer.c:1452 [inline] BUG: KASAN: use-after-free in __run_timers+0x7be/0xbe0 kernel/time/timer.c:1787 Write of size 8 at addr ffff8881e9a731c8 by task syz-fuzzer/363 CPU: 0 PID: 363 Comm: syz-fuzzer Tainted: G W 5.4.268-syzkaller-00012-g51cf29fc2bfc #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 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_del include/linux/list.h:791 [inline] detach_timer kernel/time/timer.c:824 [inline] expire_timers kernel/time/timer.c:1452 [inline] __run_timers+0x7be/0xbe0 kernel/time/timer.c:1787 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1800 __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 Allocated by task 3359: 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 getname_flags+0xb8/0x4e0 fs/namei.c:141 getname fs/namei.c:212 [inline] do_rmdir+0x121/0x580 fs/namei.c:4007 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 Freed by task 3359: 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+0x1b5/0x270 mm/kasan/common.c:487 slab_free_hook mm/slub.c:1455 [inline] slab_free_freelist_hook mm/slub.c:1494 [inline] slab_free mm/slub.c:3080 [inline] kmem_cache_free+0x10b/0x2c0 mm/slub.c:3096 putname fs/namei.c:262 [inline] do_rmdir+0x421/0x580 fs/namei.c:4048 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 The buggy address belongs to the object at ffff8881e9a72200 which belongs to the cache names_cache of size 4096 The buggy address is located 4040 bytes inside of 4096-byte region [ffff8881e9a72200, ffff8881e9a73200) The buggy address belongs to the page: page:ffffea0007a69c00 refcount:1 mapcount:0 mapping:ffff8881f5d04f00 index:0x0 compound_mapcount: 0 flags: 0x8000000000010200(slab|head) raw: 8000000000010200 dead000000000100 dead000000000122 ffff8881f5d04f00 raw: 0000000000000000 0000000000070007 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, 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+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:4891 alloc_slab_page+0x39/0x3c0 mm/slub.c:343 allocate_slab mm/slub.c:1683 [inline] new_slab+0x97/0x440 mm/slub.c:1749 new_slab_objects mm/slub.c:2505 [inline] ___slab_alloc+0x2fe/0x490 mm/slub.c:2667 __slab_alloc+0x62/0xa0 mm/slub.c:2707 slab_alloc_node mm/slub.c:2792 [inline] slab_alloc mm/slub.c:2837 [inline] kmem_cache_alloc+0x109/0x250 mm/slub.c:2842 getname_flags+0xb8/0x4e0 fs/namei.c:141 getname fs/namei.c:212 [inline] do_rmdir+0x121/0x580 fs/namei.c:4007 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:4951 [inline] __free_pages+0xaf/0x140 mm/page_alloc.c:4959 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: ffff8881e9a73080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881e9a73100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8881e9a73180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8881e9a73200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8881e9a73280: 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 1e26d1067 P4D 1e26d1067 PUD 1dd174067 PMD 0 Oops: 0010 [#1] PREEMPT SMP KASAN CPU: 0 PID: 363 Comm: syz-fuzzer Tainted: G B W 5.4.268-syzkaller-00012-g51cf29fc2bfc #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 RIP: 0010:0x0 Code: Bad RIP value. RSP: 0000:ffff8881f6e09d18 EFLAGS: 00010206 RAX: ffffffff8154e34a RBX: 0000000000000100 RCX: ffff8881dd390000 RDX: 0000000000000100 RSI: 0000000000000000 RDI: ffff8881e9a731c0 RBP: ffff8881f6e09ec8 R08: ffffffff8154df8e R09: 0000000000000003 R10: ffffffffffffffff R11: dffffc0000000001 R12: 00000000ffffa4a0 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881e9a731c0 FS: 000000c00031d490(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 00000001dd180000 CR4: 00000000003406b0 DR0: 0200000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff1 DR7: 0000000000000600 Call Trace: call_timer_fn+0x36/0x390 kernel/time/timer.c:1418 expire_timers kernel/time/timer.c:1463 [inline] __run_timers+0x879/0xbe0 kernel/time/timer.c:1787 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1800 __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 Modules linked in: CR2: 0000000000000000 ---[ end trace f1447402d158fe11 ]--- RIP: 0010:0x0 Code: Bad RIP value. RSP: 0000:ffff8881f6e09d18 EFLAGS: 00010206 RAX: ffffffff8154e34a RBX: 0000000000000100 RCX: ffff8881dd390000 RDX: 0000000000000100 RSI: 0000000000000000 RDI: ffff8881e9a731c0 RBP: ffff8881f6e09ec8 R08: ffffffff8154df8e R09: 0000000000000003 R10: ffffffffffffffff R11: dffffc0000000001 R12: 00000000ffffa4a0 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881e9a731c0 FS: 000000c00031d490(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 00000001dd180000 CR4: 00000000003406b0 DR0: 0200000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff1 DR7: 0000000000000600