================================================================== BUG: KASAN: use-after-free in hlist_add_head include/linux/list.h:930 [inline] BUG: KASAN: use-after-free in enqueue_timer+0xa6/0x480 kernel/time/timer.c:611 Write of size 8 at addr ffff8881164144c0 by task kworker/0:0/6 CPU: 0 PID: 6 Comm: kworker/0:0 Not tainted 6.1.115-syzkaller-00006-gc276c53965a8 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: events flush_stashed_error_work Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x151/0x1b7 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:316 [inline] print_report+0x158/0x4e0 mm/kasan/report.c:427 kasan_report+0x13c/0x170 mm/kasan/report.c:531 __asan_report_store8_noabort+0x17/0x20 mm/kasan/report_generic.c:356 hlist_add_head include/linux/list.h:930 [inline] enqueue_timer+0xa6/0x480 kernel/time/timer.c:611 internal_add_timer kernel/time/timer.c:640 [inline] __mod_timer+0x8d3/0xcf0 kernel/time/timer.c:1121 mod_timer+0x1f/0x30 kernel/time/timer.c:1172 ext4_update_super+0xa41/0xe50 fs/ext4/super.c:6067 ext4_commit_super+0xe3/0x4b0 fs/ext4/super.c:6086 flush_stashed_error_work+0x2ef/0x320 fs/ext4/super.c:749 process_one_work+0x73d/0xcb0 kernel/workqueue.c:2299 worker_thread+0xa60/0x1260 kernel/workqueue.c:2446 kthread+0x26d/0x300 kernel/kthread.c:386 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Allocated by task 1472: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 kasan_save_alloc_info+0x1f/0x30 mm/kasan/generic.c:505 ____kasan_kmalloc mm/kasan/common.c:379 [inline] __kasan_kmalloc+0x9c/0xb0 mm/kasan/common.c:388 kasan_kmalloc include/linux/kasan.h:212 [inline] kmalloc_trace+0x44/0xa0 mm/slab_common.c:1033 kmalloc include/linux/slab.h:557 [inline] kzalloc include/linux/slab.h:693 [inline] ext4_alloc_sbi fs/ext4/super.c:4265 [inline] ext4_fill_super+0x102/0x8460 fs/ext4/super.c:5639 get_tree_bdev+0x440/0x680 fs/super.c:1368 ext4_get_tree+0x1c/0x20 fs/ext4/super.c:5682 vfs_get_tree+0x88/0x290 fs/super.c:1575 do_new_mount+0x2ba/0xb30 fs/namespace.c:3056 path_mount+0x671/0x1070 fs/namespace.c:3386 do_mount fs/namespace.c:3399 [inline] __do_sys_mount fs/namespace.c:3607 [inline] __se_sys_mount+0x2c4/0x3b0 fs/namespace.c:3584 __x64_sys_mount+0xbf/0xd0 fs/namespace.c:3584 x64_sys_call+0x49d/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:166 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Freed by task 608: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:516 ____kasan_slab_free+0x131/0x180 mm/kasan/common.c:241 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:249 kasan_slab_free include/linux/kasan.h:178 [inline] slab_free_hook mm/slub.c:1745 [inline] slab_free_freelist_hook mm/slub.c:1771 [inline] slab_free mm/slub.c:3686 [inline] __kmem_cache_free+0x21d/0x410 mm/slub.c:3702 kfree+0x7a/0xf0 mm/slab_common.c:990 ext4_put_super+0x9e5/0xd60 fs/ext4/super.c:1313 generic_shutdown_super+0x14f/0x370 fs/super.c:503 kill_block_super+0x7e/0xe0 fs/super.c:1472 deactivate_locked_super+0xad/0x110 fs/super.c:334 deactivate_super+0xbe/0xf0 fs/super.c:365 cleanup_mnt+0x485/0x510 fs/namespace.c:1186 __cleanup_mnt+0x19/0x20 fs/namespace.c:1193 task_work_run+0x24d/0x2e0 kernel/task_work.c:203 exit_task_work include/linux/task_work.h:39 [inline] do_exit+0xbd5/0x2b80 kernel/exit.c:877 do_group_exit+0x21a/0x2d0 kernel/exit.c:1027 __do_sys_exit_group kernel/exit.c:1038 [inline] __se_sys_exit_group kernel/exit.c:1036 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1036 x64_sys_call+0x610/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 The buggy address belongs to the object at ffff888116414000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 1216 bytes inside of 4096-byte region [ffff888116414000, ffff888116415000) The buggy address belongs to the physical page: page:ffffea0004590400 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x116410 head:ffffea0004590400 order:3 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head|zone=1) raw: 4000000000010200 0000000000000000 dead000000000122 ffff888100043380 raw: 0000000000000000 0000000000040004 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), pid 1472, tgid 1471 (syz.1.217), ts 384373138954, free_ts 384333815179 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x213/0x220 mm/page_alloc.c:2590 prep_new_page+0x1b/0x110 mm/page_alloc.c:2597 get_page_from_freelist+0x2980/0x2a10 mm/page_alloc.c:4439 __alloc_pages+0x234/0x610 mm/page_alloc.c:5728 alloc_slab_page+0x6c/0xf0 allocate_slab mm/slub.c:1962 [inline] new_slab+0x90/0x3e0 mm/slub.c:2015 ___slab_alloc+0x6f9/0xb80 mm/slub.c:3203 __slab_alloc+0x5d/0xa0 mm/slub.c:3302 slab_alloc_node mm/slub.c:3387 [inline] __kmem_cache_alloc_node+0x207/0x2a0 mm/slub.c:3462 __do_kmalloc_node mm/slab_common.c:937 [inline] __kmalloc_node+0xa3/0x1e0 mm/slab_common.c:945 kmalloc_node include/linux/slab.h:583 [inline] kvmalloc_node+0x221/0x640 mm/util.c:592 kvmalloc include/linux/slab.h:710 [inline] kvzalloc include/linux/slab.h:718 [inline] kvm_recalculate_apic_map+0x431/0xf50 arch/x86/kvm/lapic.c:252 kvm_apic_set_state+0x794/0x1890 arch/x86/kvm/lapic.c:2810 kvm_vcpu_ioctl_set_lapic+0x23/0x1a0 arch/x86/kvm/x86.c:4865 kvm_arch_vcpu_ioctl+0x10e0/0x24a0 arch/x86/kvm/x86.c:5614 kvm_vcpu_ioctl+0x6d6/0xcf0 virt/kvm/kvm_main.c:4278 page last free stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] free_pages_prepare mm/page_alloc.c:1498 [inline] free_pcp_prepare mm/page_alloc.c:1572 [inline] free_unref_page_prepare+0x83d/0x850 mm/page_alloc.c:3511 free_unref_page+0xb2/0x5c0 mm/page_alloc.c:3607 free_the_page mm/page_alloc.c:798 [inline] __free_pages+0x61/0xf0 mm/page_alloc.c:5817 __free_slab+0xce/0x1a0 mm/slub.c:2039 free_slab mm/slub.c:2054 [inline] discard_slab mm/slub.c:2060 [inline] __unfreeze_partials+0x165/0x1a0 mm/slub.c:2609 put_cpu_partial+0xa9/0x100 mm/slub.c:2685 __slab_free+0x1c8/0x280 mm/slub.c:3563 do_slab_free mm/slub.c:3640 [inline] ___cache_free+0xc6/0xd0 mm/slub.c:3696 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0xc5/0x140 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x15a/0x180 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x24/0x80 mm/kasan/common.c:310 kasan_slab_alloc include/linux/kasan.h:202 [inline] slab_post_alloc_hook+0x53/0x2c0 mm/slab.h:768 slab_alloc_node mm/slub.c:3421 [inline] slab_alloc mm/slub.c:3431 [inline] __kmem_cache_alloc_lru mm/slub.c:3438 [inline] kmem_cache_alloc+0x175/0x320 mm/slub.c:3447 getname_flags+0xba/0x520 fs/namei.c:139 getname fs/namei.c:218 [inline] __do_sys_unlink fs/namei.c:4437 [inline] __se_sys_unlink fs/namei.c:4435 [inline] __x64_sys_unlink+0x3c/0x50 fs/namei.c:4435 x64_sys_call+0x289/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:88 Memory state around the buggy address: ffff888116414380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888116414400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888116414480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888116414500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888116414580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================