================================================================== BUG: KASAN: use-after-free in instrument_atomic_read_write include/linux/instrumented.h:101 [inline] BUG: KASAN: use-after-free in atomic64_try_cmpxchg_acquire include/asm-generic/atomic-instrumented.h:1515 [inline] BUG: KASAN: use-after-free in atomic_long_try_cmpxchg_acquire include/asm-generic/atomic-long.h:443 [inline] BUG: KASAN: use-after-free in __down_read_trylock kernel/locking/rwsem.c:1393 [inline] BUG: KASAN: use-after-free in down_read_trylock+0x89/0x160 kernel/locking/rwsem.c:1553 Write of size 8 at addr ffff88811cd30070 by task kworker/u4:6/9846 CPU: 1 PID: 9846 Comm: kworker/u4:6 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Workqueue: writeback wb_workfn (flush-7:5) Call Trace: __dump_stack+0x21/0x24 lib/dump_stack.c:77 dump_stack_lvl+0x1a7/0x208 lib/dump_stack.c:118 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:435 [inline] kasan_report+0x100/0x140 mm/kasan/report.c:452 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x249/0x2a0 mm/kasan/generic.c:189 __kasan_check_write+0x14/0x20 mm/kasan/shadow.c:37 instrument_atomic_read_write include/linux/instrumented.h:101 [inline] atomic64_try_cmpxchg_acquire include/asm-generic/atomic-instrumented.h:1515 [inline] atomic_long_try_cmpxchg_acquire include/asm-generic/atomic-long.h:443 [inline] __down_read_trylock kernel/locking/rwsem.c:1393 [inline] down_read_trylock+0x89/0x160 kernel/locking/rwsem.c:1553 trylock_super+0x1f/0xf0 fs/super.c:418 __writeback_inodes_wb fs/fs-writeback.c:1811 [inline] wb_writeback+0x4a4/0xb80 fs/fs-writeback.c:1926 wb_check_background_flush fs/fs-writeback.c:1994 [inline] wb_do_writeback fs/fs-writeback.c:2082 [inline] wb_workfn+0xb0a/0xf30 fs/fs-writeback.c:2110 process_one_work+0x6fd/0xbc0 kernel/workqueue.c:2301 worker_thread+0xa8e/0x13c0 kernel/workqueue.c:2447 kthread+0x324/0x3b0 kernel/kthread.c:313 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 Allocated by task 13777: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:45 [inline] set_alloc_info mm/kasan/common.c:430 [inline] ____kasan_kmalloc mm/kasan/common.c:509 [inline] __kasan_kmalloc+0xd4/0x100 mm/kasan/common.c:518 kasan_kmalloc include/linux/kasan.h:254 [inline] kmem_cache_alloc_trace+0x179/0x2e0 mm/slub.c:2979 kmalloc include/linux/slab.h:555 [inline] f2fs_kmalloc fs/f2fs/f2fs.h:3355 [inline] f2fs_kzalloc fs/f2fs/f2fs.h:3361 [inline] build_curseg fs/f2fs/segment.c:4523 [inline] f2fs_build_segment_manager+0x199c/0x48c0 fs/f2fs/segment.c:5263 f2fs_fill_super+0x4a08/0x73d0 fs/f2fs/super.c:4317 mount_bdev+0x26a/0x380 fs/super.c:1453 f2fs_mount+0x34/0x40 fs/f2fs/super.c:4598 legacy_get_tree+0xed/0x190 fs/fs_context.c:593 vfs_get_tree+0x89/0x260 fs/super.c:1583 do_new_mount+0x25a/0xa30 fs/namespace.c:3006 path_mount+0x581/0xca0 fs/namespace.c:3336 do_mount fs/namespace.c:3349 [inline] __do_sys_mount fs/namespace.c:3557 [inline] __se_sys_mount+0x320/0x390 fs/namespace.c:3534 __x64_sys_mount+0xbf/0xd0 fs/namespace.c:3534 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb Freed by task 357: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4a/0x70 mm/kasan/common.c:45 kasan_set_free_info+0x23/0x40 mm/kasan/generic.c:370 ____kasan_slab_free+0x125/0x160 mm/kasan/common.c:362 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:370 kasan_slab_free include/linux/kasan.h:220 [inline] slab_free_hook mm/slub.c:1600 [inline] slab_free_freelist_hook+0xc5/0x190 mm/slub.c:1626 slab_free mm/slub.c:3208 [inline] kfree+0xc0/0x270 mm/slub.c:4196 destroy_curseg fs/f2fs/segment.c:5339 [inline] f2fs_destroy_segment_manager+0xa21/0xd80 fs/f2fs/segment.c:5387 f2fs_put_super+0x6b4/0xbd0 fs/f2fs/super.c:1644 generic_shutdown_super+0x149/0x320 fs/super.c:465 kill_block_super+0x7f/0xf0 fs/super.c:1480 kill_f2fs_super+0x30a/0x3d0 fs/f2fs/super.c:4630 deactivate_locked_super+0xa0/0x100 fs/super.c:335 deactivate_super+0xaf/0xe0 fs/super.c:366 cleanup_mnt+0x44f/0x500 fs/namespace.c:1123 __cleanup_mnt+0x19/0x20 fs/namespace.c:1130 task_work_run+0x127/0x190 kernel/task_work.c:189 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_user_mode_loop+0xcb/0xe0 kernel/entry/common.c:172 exit_to_user_mode_prepare+0x76/0xa0 kernel/entry/common.c:199 syscall_exit_to_user_mode+0x1d/0x40 kernel/entry/common.c:274 do_syscall_64+0x3d/0x40 arch/x86/entry/common.c:56 entry_SYSCALL_64_after_hwframe+0x61/0xcb Last potentially related work creation: kasan_save_stack+0x3a/0x60 mm/kasan/common.c:38 __kasan_record_aux_stack+0xd2/0x100 mm/kasan/generic.c:348 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:358 insert_work+0x51/0x320 kernel/workqueue.c:1352 __queue_work+0x91f/0xca0 kernel/workqueue.c:1518 queue_work_on+0xe6/0x140 kernel/workqueue.c:1545 queue_work include/linux/workqueue.h:515 [inline] schedule_work include/linux/workqueue.h:576 [inline] destroy_super_rcu+0xd1/0xe0 fs/super.c:172 rcu_do_batch+0x488/0xaf0 kernel/rcu/tree.c:2494 rcu_core+0x50a/0xca0 kernel/rcu/tree.c:2735 rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2748 __do_softirq+0x255/0x563 kernel/softirq.c:309 Second to last potentially related work creation: kasan_save_stack+0x3a/0x60 mm/kasan/common.c:38 __kasan_record_aux_stack+0xd2/0x100 mm/kasan/generic.c:348 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:358 __call_rcu kernel/rcu/tree.c:2980 [inline] call_rcu+0x11a/0x1090 kernel/rcu/tree.c:3054 __put_super+0x254/0x2b0 fs/super.c:299 put_super fs/super.c:313 [inline] deactivate_locked_super+0xd4/0x100 fs/super.c:346 deactivate_super+0xaf/0xe0 fs/super.c:366 cleanup_mnt+0x44f/0x500 fs/namespace.c:1123 __cleanup_mnt+0x19/0x20 fs/namespace.c:1130 task_work_run+0x127/0x190 kernel/task_work.c:189 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_user_mode_loop+0xcb/0xe0 kernel/entry/common.c:172 exit_to_user_mode_prepare+0x76/0xa0 kernel/entry/common.c:199 syscall_exit_to_user_mode+0x1d/0x40 kernel/entry/common.c:274 do_syscall_64+0x3d/0x40 arch/x86/entry/common.c:56 entry_SYSCALL_64_after_hwframe+0x61/0xcb The buggy address belongs to the object at ffff88811cd30000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 112 bytes inside of 2048-byte region [ffff88811cd30000, ffff88811cd30800) The buggy address belongs to the page: page:ffffea0004734c00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11cd30 head:ffffea0004734c00 order:3 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head) raw: 4000000000010200 dead000000000100 dead000000000122 ffff888100042d80 raw: 0000000000000000 0000000000080008 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 213, ts 13889194571, free_ts 0 set_page_owner include/linux/page_owner.h:35 [inline] post_alloc_hook mm/page_alloc.c:2456 [inline] prep_new_page+0x176/0x190 mm/page_alloc.c:2462 get_page_from_freelist+0x225f/0x23f0 mm/page_alloc.c:4254 __alloc_pages_nodemask+0x29a/0x640 mm/page_alloc.c:5384 alloc_slab_page mm/slub.c:-1 [inline] allocate_slab mm/slub.c:1813 [inline] new_slab+0x84/0x3f0 mm/slub.c:1874 new_slab_objects mm/slub.c:2632 [inline] ___slab_alloc+0x2f8/0x4c0 mm/slub.c:2796 __slab_alloc+0x63/0xa0 mm/slub.c:2836 slab_alloc_node mm/slub.c:2918 [inline] slab_alloc mm/slub.c:2960 [inline] __kmalloc_track_caller+0x1e4/0x310 mm/slub.c:4541 kmemdup+0x26/0x60 mm/util.c:131 bpf_prog_store_orig_filter net/core/filter.c:1153 [inline] bpf_prog_create_from_user+0x284/0x420 net/core/filter.c:1438 seccomp_prepare_filter kernel/seccomp.c:661 [inline] seccomp_prepare_user_filter kernel/seccomp.c:698 [inline] seccomp_set_mode_filter kernel/seccomp.c:1813 [inline] do_seccomp+0x7ff/0x1480 kernel/seccomp.c:1933 prctl_set_seccomp+0x4c/0x60 kernel/seccomp.c:1986 __do_sys_prctl kernel/sys.c:2457 [inline] __se_sys_prctl+0x77d/0x1230 kernel/sys.c:2375 __x64_sys_prctl+0xbf/0xd0 kernel/sys.c:2375 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb page_owner free stack trace missing Memory state around the buggy address: ffff88811cd2ff00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88811cd2ff80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88811cd30000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88811cd30080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88811cd30100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================