================================================================== BUG: KASAN: use-after-free in instrument_atomic_read include/linux/instrumented.h:71 [inline] BUG: KASAN: use-after-free in atomic_long_read include/linux/atomic/atomic-instrumented.h:1183 [inline] BUG: KASAN: use-after-free in __down_read_trylock kernel/locking/rwsem.c:1348 [inline] BUG: KASAN: use-after-free in down_read_trylock+0x9d/0x630 kernel/locking/rwsem.c:1624 Read of size 8 at addr ffff8881124f8070 by task kworker/u4:2/45 CPU: 0 PID: 45 Comm: kworker/u4:2 Tainted: G W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026 Workqueue: writeback wb_workfn (flush-7:9) Call Trace: __dump_stack+0x21/0x30 lib/dump_stack.c:88 dump_stack_lvl+0x110/0x170 lib/dump_stack.c:106 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:427 [inline] kasan_report+0x10f/0x150 mm/kasan/report.c:444 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x249/0x2a0 mm/kasan/generic.c:189 __kasan_check_read+0x11/0x20 mm/kasan/shadow.c:31 instrument_atomic_read include/linux/instrumented.h:71 [inline] atomic_long_read include/linux/atomic/atomic-instrumented.h:1183 [inline] __down_read_trylock kernel/locking/rwsem.c:1348 [inline] down_read_trylock+0x9d/0x630 kernel/locking/rwsem.c:1624 trylock_super+0x1f/0xf0 fs/super.c:418 __writeback_inodes_wb+0x111/0x400 fs/fs-writeback.c:2002 wb_writeback+0x3ff/0x990 fs/fs-writeback.c:2118 wb_check_background_flush fs/fs-writeback.c:2188 [inline] wb_do_writeback fs/fs-writeback.c:2276 [inline] wb_workfn+0xb0a/0xf30 fs/fs-writeback.c:2304 process_one_work+0x6c8/0xbb0 kernel/workqueue.c:2328 worker_thread+0xaa0/0x1250 kernel/workqueue.c:2475 kthread+0x3f5/0x4f0 kernel/kthread.c:337 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Allocated by task 10041: 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:433 [inline] ____kasan_kmalloc mm/kasan/common.c:512 [inline] __kasan_kmalloc+0xd4/0x100 mm/kasan/common.c:521 kasan_kmalloc include/linux/kasan.h:227 [inline] kmem_cache_alloc_trace+0x119/0x270 mm/slub.c:3274 kmalloc include/linux/slab.h:619 [inline] kzalloc include/linux/slab.h:750 [inline] alloc_super+0x5e/0x840 fs/super.c:203 sget+0x1e2/0x4c0 fs/super.c:637 mount_bdev+0xec/0x3c0 fs/super.c:1373 f2fs_mount+0x34/0x40 fs/f2fs/super.c:4713 legacy_get_tree+0xed/0x190 fs/fs_context.c:611 vfs_get_tree+0x89/0x260 fs/super.c:1530 do_new_mount+0x251/0xb40 fs/namespace.c:3037 path_mount+0x640/0xff0 fs/namespace.c:3367 do_mount fs/namespace.c:3380 [inline] __do_sys_mount fs/namespace.c:3588 [inline] __se_sys_mount+0x320/0x390 fs/namespace.c:3565 __x64_sys_mount+0xbf/0xd0 fs/namespace.c:3565 x64_sys_call+0x6bf/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:166 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 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+0x51/0x310 kernel/workqueue.c:1373 __queue_work+0x8e1/0xc60 kernel/workqueue.c:1539 queue_work_on+0xde/0x150 kernel/workqueue.c:1566 queue_work include/linux/workqueue.h:510 [inline] schedule_work include/linux/workqueue.h:571 [inline] destroy_super_rcu+0xd1/0xe0 fs/super.c:172 rcu_do_batch+0x4c1/0xbf0 kernel/rcu/tree.c:2523 rcu_core+0x4a3/0xef0 kernel/rcu/tree.c:2763 rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2776 handle_softirqs+0x250/0x560 kernel/softirq.c:583 __do_softirq kernel/softirq.c:621 [inline] invoke_softirq kernel/softirq.c:443 [inline] __irq_exit_rcu+0x52/0xf0 kernel/softirq.c:670 irq_exit_rcu+0x9/0x10 kernel/softirq.c:682 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0xa9/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x1b/0x20 arch/x86/include/asm/idtentry.h:676 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_common kernel/rcu/tree.c:3011 [inline] call_rcu+0x10b/0xf60 kernel/rcu/tree.c:3129 __put_super+0x26b/0x2d0 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:1149 __cleanup_mnt+0x19/0x20 fs/namespace.c:1156 task_work_run+0x127/0x190 kernel/task_work.c:188 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop+0xd0/0xe0 kernel/entry/common.c:181 exit_to_user_mode_prepare+0x87/0xd0 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 The buggy address belongs to the object at ffff8881124f8000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 112 bytes inside of 2048-byte region [ffff8881124f8000, ffff8881124f8800) The buggy address belongs to the page: page:ffffea0004493e00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8881124fb000 pfn:0x1124f8 head:ffffea0004493e00 order:3 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head|zone=1) raw: 4000000000010200 ffffea0005051608 ffffea0004e19808 ffff888100043200 raw: ffff8881124fb000 0000000000080002 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 285, ts 33316662320, free_ts 32403277456 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x192/0x1b0 mm/page_alloc.c:2607 prep_new_page+0x1c/0x110 mm/page_alloc.c:2613 get_page_from_freelist+0x2c3a/0x2cd0 mm/page_alloc.c:4487 __alloc_pages+0x1a2/0x460 mm/page_alloc.c:5824 alloc_slab_page mm/slub.c:-1 [inline] allocate_slab mm/slub.c:1937 [inline] new_slab+0xa0/0x4d0 mm/slub.c:2000 ___slab_alloc+0x3ac/0x840 mm/slub.c:3033 __slab_alloc+0x49/0x90 mm/slub.c:3120 slab_alloc_node mm/slub.c:3211 [inline] slab_alloc mm/slub.c:3255 [inline] __kmalloc+0x16a/0x2c0 mm/slub.c:4432 __kmalloc_node include/linux/slab.h:487 [inline] kmalloc_node include/linux/slab.h:642 [inline] kvmalloc_node+0x211/0x320 mm/util.c:621 kvmalloc include/linux/mm.h:862 [inline] kvmalloc_array include/linux/mm.h:880 [inline] alloc_fdtable+0x10b/0x2e0 fs/file.c:150 dup_fd+0x896/0xad0 fs/file.c:345 copy_files+0x76/0xe0 kernel/fork.c:1631 copy_process+0x1080/0x3230 kernel/fork.c:2343 kernel_clone+0x233/0x960 kernel/fork.c:2744 __do_sys_clone kernel/fork.c:2870 [inline] __se_sys_clone kernel/fork.c:2854 [inline] __x64_sys_clone+0x198/0x210 kernel/fork.c:2854 x64_sys_call+0x41f/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:57 page last free stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] free_pages_prepare mm/page_alloc.c:1474 [inline] free_pcp_prepare mm/page_alloc.c:1546 [inline] free_unref_page_prepare+0x5fa/0x600 mm/page_alloc.c:3536 free_unref_page+0xae/0x540 mm/page_alloc.c:3618 free_the_page mm/page_alloc.c:805 [inline] __free_pages+0x6c/0x100 mm/page_alloc.c:5900 __free_slab+0xe5/0x1e0 mm/slub.c:2025 free_slab mm/slub.c:2040 [inline] discard_slab mm/slub.c:2046 [inline] __unfreeze_partials+0x15a/0x190 mm/slub.c:2532 put_cpu_partial+0xc6/0x120 mm/slub.c:2612 __slab_free+0x1d4/0x290 mm/slub.c:3395 do_slab_free mm/slub.c:3514 [inline] ___cache_free+0x104/0x120 mm/slub.c:3535 qlink_free+0x4d/0x90 mm/kasan/quarantine.c:157 qlist_free_all+0x5f/0xb0 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x14a/0x170 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0x2f/0xe0 mm/kasan/common.c:443 kasan_slab_alloc include/linux/kasan.h:217 [inline] slab_post_alloc_hook+0x4f/0x2b0 mm/slab.h:550 slab_alloc_node mm/slub.c:3245 [inline] slab_alloc mm/slub.c:3255 [inline] kmem_cache_alloc+0xf7/0x260 mm/slub.c:3260 kmem_cache_alloc_node include/linux/slab.h:492 [inline] __alloc_skb+0xe4/0x730 net/core/skbuff.c:416 alloc_skb include/linux/skbuff.h:1183 [inline] alloc_skb_with_frags+0xa8/0x620 net/core/skbuff.c:6220 Memory state around the buggy address: ffff8881124f7f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8881124f7f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff8881124f8000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8881124f8080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881124f8100: fb fb 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