================================================================== 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 ffff88811ced44c0 by task kworker/1:6/886 CPU: 1 PID: 886 Comm: kworker/1:6 Not tainted 6.1.78-syzkaller-00009-g25216be1ac5e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 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:1167 ext4_update_super+0xa41/0xe50 fs/ext4/super.c:6043 ext4_commit_super+0xe3/0x4b0 fs/ext4/super.c:6062 flush_stashed_error_work+0x2ef/0x320 fs/ext4/super.c:748 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:306 Allocated by task 5722: 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:1052 kmalloc include/linux/slab.h:553 [inline] kzalloc include/linux/slab.h:689 [inline] ext4_alloc_sbi fs/ext4/super.c:4264 [inline] ext4_fill_super+0x102/0x8460 fs/ext4/super.c:5638 get_tree_bdev+0x440/0x680 fs/super.c:1357 ext4_get_tree+0x1c/0x20 fs/ext4/super.c:5681 vfs_get_tree+0x88/0x290 fs/super.c:1564 do_new_mount+0x2ba/0xb30 fs/namespace.c:3051 path_mount+0x671/0x1070 fs/namespace.c:3381 do_mount fs/namespace.c:3394 [inline] __do_sys_mount fs/namespace.c:3602 [inline] __se_sys_mount+0x2c4/0x3b0 fs/namespace.c:3579 __x64_sys_mount+0xbf/0xd0 fs/namespace.c:3579 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x63/0xcd Freed by task 4579: 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:3684 [inline] __kmem_cache_free+0x218/0x3b0 mm/slub.c:3697 kfree+0x7a/0xf0 mm/slab_common.c:1009 ext4_put_super+0x9e5/0xd60 fs/ext4/super.c:1312 generic_shutdown_super+0x14f/0x370 fs/super.c:503 kill_block_super+0x7e/0xe0 fs/super.c:1461 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:179 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0xbd5/0x2b80 kernel/exit.c:875 do_group_exit+0x21a/0x2d0 kernel/exit.c:1025 __do_sys_exit_group kernel/exit.c:1036 [inline] __se_sys_exit_group kernel/exit.c:1034 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1034 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x63/0xcd The buggy address belongs to the object at ffff88811ced4000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 1216 bytes inside of 4096-byte region [ffff88811ced4000, ffff88811ced5000) The buggy address belongs to the physical page: page:ffffea000473b400 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11ced0 head:ffffea000473b400 order:3 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head|zone=1) raw: 4000000000010200 ffffea0004716200 dead000000000002 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 2950, tgid 2950 (syz-executor.0), ts 152753264498, free_ts 152736917534 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+0x27ea/0x2870 mm/page_alloc.c:4425 __alloc_pages+0x3a1/0x780 mm/page_alloc.c:5712 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+0x1af/0x250 mm/slub.c:3460 kmalloc_trace+0x2a/0xa0 mm/slab_common.c:1047 kmalloc include/linux/slab.h:553 [inline] kvm_uevent_notify_change+0x22b/0x3c0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:5728 kvm_destroy_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:1304 [inline] kvm_put_kvm+0x99/0x1340 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1370 kvm_vm_release+0x46/0x50 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1393 __fput+0x3ab/0x870 fs/file_table.c:320 ____fput+0x15/0x20 fs/file_table.c:348 task_work_run+0x24d/0x2e0 kernel/task_work.c:179 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:3498 free_unref_page+0xb2/0x5c0 mm/page_alloc.c:3594 free_the_page mm/page_alloc.c:798 [inline] free_compound_page+0x9d/0xd0 mm/page_alloc.c:821 destroy_large_folio+0x56/0x90 mm/page_alloc.c:858 __folio_put_large mm/swap.c:118 [inline] __folio_put+0xcf/0xe0 mm/swap.c:126 folio_put include/linux/mm.h:1422 [inline] put_page include/linux/mm.h:1474 [inline] page_to_skb+0x75d/0xba0 drivers/net/virtio_net.c:556 receive_mergeable drivers/net/virtio_net.c:1128 [inline] receive_buf+0x4fc/0x4ef0 drivers/net/virtio_net.c:1267 virtnet_receive drivers/net/virtio_net.c:1562 [inline] virtnet_poll+0x6d3/0x1470 drivers/net/virtio_net.c:1680 __napi_poll+0xbe/0x5c0 net/core/dev.c:6544 napi_poll net/core/dev.c:6611 [inline] net_rx_action+0x595/0xdd0 net/core/dev.c:6722 __do_softirq+0x1d8/0x661 kernel/softirq.c:617 Memory state around the buggy address: ffff88811ced4380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88811ced4400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88811ced4480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88811ced4500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88811ced4580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================