================================================================== 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+0xba/0x1d0 kernel/locking/rwsem.c:1553 Write of size 8 at addr ffff888127464070 by task kworker/u4:4/386 CPU: 1 PID: 386 Comm: kworker/u4:4 Tainted: G W 5.10.234-syzkaller-00023-g3f5f2283d684 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: writeback wb_workfn (flush-7:5) Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack_lvl+0x1e2/0x24b lib/dump_stack.c:118 print_address_description+0x81/0x3b0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:435 [inline] kasan_report+0x179/0x1c0 mm/kasan/report.c:452 kasan_check_range+0x293/0x2a0 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+0xba/0x1d0 kernel/locking/rwsem.c:1553 trylock_super+0x1f/0xf0 fs/super.c:418 __writeback_inodes_wb fs/fs-writeback.c:1795 [inline] wb_writeback+0x49d/0xc60 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+0xb3d/0x1110 fs/fs-writeback.c:2094 process_one_work+0x6dc/0xbd0 kernel/workqueue.c:2301 worker_thread+0xaea/0x1510 kernel/workqueue.c:2447 kthread+0x34b/0x3d0 kernel/kthread.c:313 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 Allocated by task 21829: 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+0xdb/0x110 mm/kasan/common.c:509 __kasan_kmalloc+0x9/0x10 mm/kasan/common.c:518 kasan_kmalloc include/linux/kasan.h:254 [inline] kmem_cache_alloc_trace+0x18a/0x2e0 mm/slub.c:2974 kmalloc include/linux/slab.h:552 [inline] kzalloc include/linux/slab.h:664 [inline] alloc_super+0x5d/0x780 fs/super.c:203 sget+0x1e5/0x4c0 fs/super.c:627 mount_bdev+0xea/0x370 fs/super.c:1415 f2fs_mount+0x34/0x40 fs/f2fs/super.c:4548 legacy_get_tree+0xf1/0x190 fs/fs_context.c:593 vfs_get_tree+0x88/0x290 fs/super.c:1572 do_new_mount+0x2ba/0xb30 fs/namespace.c:2917 path_mount+0x56f/0xcb0 fs/namespace.c:3247 do_mount fs/namespace.c:3260 [inline] __do_sys_mount fs/namespace.c:3468 [inline] __se_sys_mount+0x2c4/0x3b0 fs/namespace.c:3445 __x64_sys_mount+0xbf/0xd0 fs/namespace.c:3445 do_syscall_64+0x34/0x70 entry_SYSCALL_64_after_hwframe+0x61/0xcb Last potentially related work creation: kasan_save_stack+0x3b/0x60 mm/kasan/common.c:38 __kasan_record_aux_stack+0xd3/0x100 mm/kasan/generic.c:348 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:358 insert_work+0x56/0x310 kernel/workqueue.c:1352 __queue_work+0x970/0xd10 kernel/workqueue.c:1518 queue_work_on+0x105/0x160 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+0x597/0xc40 kernel/rcu/tree.c:2494 rcu_core+0x5ad/0xe40 kernel/rcu/tree.c:2735 rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2748 __do_softirq+0x268/0x5bb kernel/softirq.c:309 Second to last potentially related work creation: kasan_save_stack+0x3b/0x60 mm/kasan/common.c:38 __kasan_record_aux_stack+0xd3/0x100 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+0x135/0x11f0 kernel/rcu/tree.c:3050 __put_super+0x25c/0x2b0 fs/super.c:299 put_super fs/super.c:313 [inline] deactivate_locked_super+0xe1/0x110 fs/super.c:346 deactivate_super+0xbe/0xf0 fs/super.c:366 cleanup_mnt+0x45c/0x510 fs/namespace.c:1118 __cleanup_mnt+0x19/0x20 fs/namespace.c:1125 task_work_run+0x129/0x190 kernel/task_work.c:189 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_user_mode_loop+0xbf/0xd0 kernel/entry/common.c:172 exit_to_user_mode_prepare kernel/entry/common.c:199 [inline] syscall_exit_to_user_mode+0xa2/0x1a0 kernel/entry/common.c:274 do_syscall_64+0x40/0x70 arch/x86/entry/common.c:56 entry_SYSCALL_64_after_hwframe+0x61/0xcb The buggy address belongs to the object at ffff888127464000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 112 bytes inside of 2048-byte region [ffff888127464000, ffff888127464800) The buggy address belongs to the page: page:ffffea00049d1800 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888127464000 pfn:0x127460 head:ffffea00049d1800 order:3 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head) raw: 4000000000010200 ffffea0004590408 ffffea00043ee408 ffff888100042d80 raw: ffff888127464000 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 0x1d2a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 339, ts 23221199469, free_ts 23220474944 set_page_owner include/linux/page_owner.h:35 [inline] post_alloc_hook mm/page_alloc.c:2456 [inline] prep_new_page+0x166/0x180 mm/page_alloc.c:2462 get_page_from_freelist+0x2d8c/0x2f30 mm/page_alloc.c:4254 __alloc_pages_nodemask+0x435/0xaf0 mm/page_alloc.c:5348 allocate_slab mm/slub.c:1808 [inline] new_slab+0x80/0x400 mm/slub.c:1869 new_slab_objects mm/slub.c:2627 [inline] ___slab_alloc+0x302/0x4b0 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+0x1f8/0x320 mm/slub.c:4536 __kmalloc_reserve net/core/skbuff.c:144 [inline] __alloc_skb+0xbc/0x510 net/core/skbuff.c:212 alloc_skb include/linux/skbuff.h:1126 [inline] alloc_skb_with_frags+0xa1/0x570 net/core/skbuff.c:5993 sock_alloc_send_pskb+0x915/0xa50 net/core/sock.c:2388 sock_alloc_send_skb+0x32/0x40 net/core/sock.c:2405 mld_newpack+0x1b2/0x990 net/ipv6/mcast.c:1604 add_grhead net/ipv6/mcast.c:1707 [inline] add_grec+0xf63/0x13b0 net/ipv6/mcast.c:1838 mld_send_initial_cr+0x1ef/0x2b0 net/ipv6/mcast.c:2088 mld_dad_timer_expire+0x30/0x3f0 net/ipv6/mcast.c:2112 call_timer_fn+0x3b/0x2d0 kernel/time/timer.c:1450 page last free stack trace: reset_page_owner include/linux/page_owner.h:28 [inline] free_pages_prepare mm/page_alloc.c:1349 [inline] free_pcp_prepare mm/page_alloc.c:1421 [inline] free_unref_page_prepare+0x2ae/0x2d0 mm/page_alloc.c:3336 free_unref_page mm/page_alloc.c:3391 [inline] free_the_page+0x9e/0x370 mm/page_alloc.c:5407 __free_pages+0x67/0xc0 mm/page_alloc.c:5418 __vunmap+0x7c1/0x940 mm/vmalloc.c:2301 __vfree mm/vmalloc.c:2350 [inline] vfree+0x5c/0x80 mm/vmalloc.c:2381 kcov_mmap+0x93/0x130 kernel/kcov.c:489 call_mmap include/linux/fs.h:2063 [inline] mmap_file+0x5f/0xb0 mm/util.c:1085 __mmap_region mm/mmap.c:1872 [inline] mmap_region+0x149f/0x1cd0 mm/mmap.c:3063 do_mmap+0x800/0xeb0 mm/mmap.c:1649 vm_mmap_pgoff+0x201/0x390 mm/util.c:543 ksys_mmap_pgoff+0x16f/0x1f0 mm/mmap.c:1700 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:95 [inline] __se_sys_mmap arch/x86/kernel/sys_x86_64.c:86 [inline] __x64_sys_mmap+0x103/0x120 arch/x86/kernel/sys_x86_64.c:86 do_syscall_64+0x34/0x70 entry_SYSCALL_64_after_hwframe+0x61/0xcb Memory state around the buggy address: ffff888127463f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888127463f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888127464000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888127464080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888127464100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================