================================================================== 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 ffff8881307624c0 by task kworker/0:2/301 CPU: 0 PID: 301 Comm: kworker/0:2 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 12873: 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 11105: 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 ffff888130762000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 1216 bytes inside of 4096-byte region [ffff888130762000, ffff888130763000) The buggy address belongs to the physical page: page:ffffea0004c1d800 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x130760 head:ffffea0004c1d800 order:3 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head|zone=1) raw: 4000000000010200 dead000000000100 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 292, tgid 292 (syz-executor), ts 24933001079, free_ts 0 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_track_caller+0xa2/0x1e0 mm/slab_common.c:958 kmemdup+0x29/0x60 mm/util.c:134 _Z7kmemdupPKvU17pass_object_size0mj include/linux/fortify-string.h:585 [inline] __addrconf_sysctl_register+0xad/0x3e0 net/ipv6/addrconf.c:7132 addrconf_sysctl_register+0x141/0x1a0 net/ipv6/addrconf.c:7197 ipv6_add_dev+0xbd7/0x11a0 net/ipv6/addrconf.c:453 addrconf_notify+0x6d2/0xe10 net/ipv6/addrconf.c:3601 notifier_call_chain kernel/notifier.c:87 [inline] raw_notifier_call_chain+0x8c/0xf0 kernel/notifier.c:455 page_owner free stack trace missing Memory state around the buggy address: ffff888130762380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888130762400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888130762480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888130762500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888130762580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================