================================================================== 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+0x83/0x150 kernel/locking/rwsem.c:1553 Write of size 8 at addr ffff888126f22070 by task kworker/u4:3/296 CPU: 0 PID: 296 Comm: kworker/u4:3 Not tainted 5.10.237-syzkaller-00010-gcf6ed0f1511d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: writeback wb_workfn (flush-7:7) Call Trace: __dump_stack+0x21/0x24 lib/dump_stack.c:77 dump_stack_lvl+0x169/0x1d8 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+0xe2/0x130 mm/kasan/report.c:452 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x280/0x290 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+0x83/0x150 kernel/locking/rwsem.c:1553 trylock_super+0x1f/0xf0 fs/super.c:418 __writeback_inodes_wb fs/fs-writeback.c:1795 [inline] wb_writeback+0x485/0xb90 fs/fs-writeback.c:1910 wb_check_old_data_flush fs/fs-writeback.c:2012 [inline] wb_do_writeback fs/fs-writeback.c:2065 [inline] wb_workfn+0x9ae/0xe20 fs/fs-writeback.c:2094 process_one_work+0x6e1/0xba0 kernel/workqueue.c:2301 worker_thread+0xa6a/0x13b0 kernel/workqueue.c:2447 kthread+0x346/0x3d0 kernel/kthread.c:313 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 Allocated by task 9608: 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+0xda/0x110 mm/kasan/common.c:518 kasan_kmalloc include/linux/kasan.h:254 [inline] kmem_cache_alloc_trace+0x184/0x2e0 mm/slub.c:2974 kmalloc include/linux/slab.h:552 [inline] kzalloc include/linux/slab.h:664 [inline] ext4_fill_super+0xcc/0x8b60 fs/ext4/super.c:4018 mount_bdev+0x28b/0x3a0 fs/super.c:1442 ext4_mount+0x34/0x40 fs/ext4/super.c:6662 legacy_get_tree+0xed/0x190 fs/fs_context.c:593 vfs_get_tree+0x89/0x260 fs/super.c:1572 do_new_mount+0x25a/0xa20 fs/namespace.c:2918 path_mount+0x572/0xc80 fs/namespace.c:3248 do_mount fs/namespace.c:3261 [inline] __do_sys_mount fs/namespace.c:3469 [inline] __se_sys_mount+0x318/0x380 fs/namespace.c:3446 __x64_sys_mount+0xbf/0xd0 fs/namespace.c:3446 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 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+0x52/0x310 kernel/workqueue.c:1352 __queue_work+0x923/0xca0 kernel/workqueue.c:1518 queue_work_on+0xd5/0x130 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+0x4df/0xa80 kernel/rcu/tree.c:2494 rcu_core+0x55f/0xd60 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:2976 [inline] call_rcu+0x105/0x1040 kernel/rcu/tree.c:3050 __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+0x446/0x500 fs/namespace.c:1118 __cleanup_mnt+0x19/0x20 fs/namespace.c:1125 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 kernel/entry/common.c:199 [inline] syscall_exit_to_user_mode+0x68/0x90 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 ffff888126f22000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 112 bytes inside of 2048-byte region [ffff888126f22000, ffff888126f22800) The buggy address belongs to the page: page:ffffea00049bc800 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888126f23000 pfn:0x126f20 head:ffffea00049bc800 order:3 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head) raw: 4000000000010200 ffffea00044a2e08 ffffea00047bee08 ffff888100042d80 raw: ffff888126f23000 0000000000080001 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 276, ts 26775616975, 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+0x179/0x180 mm/page_alloc.c:2462 get_page_from_freelist+0x2235/0x23d0 mm/page_alloc.c:4254 __alloc_pages_nodemask+0x268/0x5f0 mm/page_alloc.c:5349 alloc_slab_page mm/slub.c:-1 [inline] allocate_slab mm/slub.c:1808 [inline] new_slab+0x84/0x3f0 mm/slub.c:1869 new_slab_objects mm/slub.c:2627 [inline] ___slab_alloc+0x2a6/0x450 mm/slub.c:2791 __slab_alloc+0x63/0xa0 mm/slub.c:2831 slab_alloc_node mm/slub.c:2913 [inline] slab_alloc mm/slub.c:2955 [inline] __kmalloc_track_caller+0x1ef/0x320 mm/slub.c:4536 kmemdup+0x26/0x60 mm/util.c:131 neigh_sysctl_register+0xaf/0xa70 net/core/neighbour.c:3652 devinet_sysctl_register+0xaf/0x1e0 net/ipv4/devinet.c:2636 inetdev_init+0x273/0x480 net/ipv4/devinet.c:277 inetdev_event+0x1f8/0x1030 net/ipv4/devinet.c:1545 notifier_call_chain kernel/notifier.c:83 [inline] raw_notifier_call_chain+0x90/0x100 kernel/notifier.c:410 call_netdevice_notifiers_info net/core/dev.c:2054 [inline] call_netdevice_notifiers_extack net/core/dev.c:2066 [inline] call_netdevice_notifiers+0x111/0x190 net/core/dev.c:2080 register_netdevice+0x1043/0x13c0 net/core/dev.c:10087 veth_newlink+0x853/0xbb0 drivers/net/veth.c:1387 page_owner free stack trace missing Memory state around the buggy address: ffff888126f21f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888126f21f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888126f22000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888126f22080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888126f22100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================