================================================================== BUG: KASAN: use-after-free in arch_atomic_read arch/x86/include/asm/atomic.h:29 [inline] BUG: KASAN: use-after-free in atomic_read include/linux/atomic/atomic-instrumented.h:28 [inline] BUG: KASAN: use-after-free in kernfs_get+0x8a/0x90 fs/kernfs/dir.c:504 Read of size 4 at addr ffff888123c5c4b0 by task kworker/0:8/4414 CPU: 0 PID: 4414 Comm: kworker/0:8 Not tainted 5.15.156-syzkaller-00821-g29d153aabd54 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 Workqueue: events flush_stashed_error_work Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x151/0x1c0 lib/dump_stack.c:106 print_address_description+0x87/0x3b0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:427 [inline] kasan_report+0x179/0x1c0 mm/kasan/report.c:444 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:308 arch_atomic_read arch/x86/include/asm/atomic.h:29 [inline] atomic_read include/linux/atomic/atomic-instrumented.h:28 [inline] kernfs_get+0x8a/0x90 fs/kernfs/dir.c:504 sysfs_notify+0x9a/0xd0 fs/sysfs/file.c:190 ext4_notify_error_sysfs+0x25/0x30 fs/ext4/sysfs.c:516 flush_stashed_error_work+0x302/0x320 process_one_work+0x6bb/0xc10 kernel/workqueue.c:2325 worker_thread+0xad5/0x12a0 kernel/workqueue.c:2472 kthread+0x421/0x510 kernel/kthread.c:337 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:300 Allocated by task 21699: 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_slab_alloc+0xb1/0xe0 mm/kasan/common.c:466 kasan_slab_alloc include/linux/kasan.h:217 [inline] slab_post_alloc_hook+0x53/0x2c0 mm/slab.h:550 slab_alloc_node mm/slub.c:3240 [inline] slab_alloc mm/slub.c:3248 [inline] kmem_cache_alloc+0xf5/0x200 mm/slub.c:3253 kmem_cache_zalloc include/linux/slab.h:723 [inline] __kernfs_new_node+0xdb/0x700 fs/kernfs/dir.c:593 kernfs_new_node+0x130/0x230 fs/kernfs/dir.c:669 kernfs_create_dir_ns+0x44/0x130 fs/kernfs/dir.c:1017 sysfs_create_dir_ns+0x185/0x390 fs/sysfs/dir.c:59 create_dir lib/kobject.c:89 [inline] kobject_add_internal+0x763/0xd90 lib/kobject.c:263 kobject_add_varg lib/kobject.c:398 [inline] kobject_init_and_add+0x120/0x190 lib/kobject.c:481 ext4_register_sysfs+0xbf/0x2c0 fs/ext4/sysfs.c:529 ext4_fill_super+0x8a31/0x96e0 fs/ext4/super.c:4940 mount_bdev+0x282/0x3b0 fs/super.c:1387 ext4_mount+0x34/0x40 fs/ext4/super.c:6593 legacy_get_tree+0xf1/0x190 fs/fs_context.c:611 vfs_get_tree+0x88/0x290 fs/super.c:1517 do_new_mount+0x2ba/0xb30 fs/namespace.c:3005 path_mount+0x671/0x1070 fs/namespace.c:3335 do_mount fs/namespace.c:3348 [inline] __do_sys_mount fs/namespace.c:3556 [inline] __se_sys_mount+0x2c4/0x3b0 fs/namespace.c:3533 __x64_sys_mount+0xbf/0xd0 fs/namespace.c:3533 x64_sys_call+0x49d/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:166 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Freed by task 16708: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:45 kasan_set_free_info+0x23/0x40 mm/kasan/generic.c:370 ____kasan_slab_free+0x126/0x160 mm/kasan/common.c:365 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:373 kasan_slab_free include/linux/kasan.h:193 [inline] slab_free_hook mm/slub.c:1723 [inline] slab_free_freelist_hook+0xbd/0x190 mm/slub.c:1749 slab_free mm/slub.c:3519 [inline] kmem_cache_free+0x116/0x2e0 mm/slub.c:3535 kernfs_put+0x392/0x520 fs/kernfs/dir.c:547 sysfs_put include/linux/sysfs.h:641 [inline] __kobject_del+0x10f/0x300 lib/kobject.c:629 kobject_del+0x45/0x60 lib/kobject.c:651 ext4_unregister_sysfs+0x91/0xa0 fs/ext4/sysfs.c:563 ext4_put_super+0x80/0xd20 fs/ext4/super.c:1182 generic_shutdown_super+0x157/0x2e0 fs/super.c:475 kill_block_super+0x7e/0xe0 fs/super.c:1414 deactivate_locked_super+0xad/0x110 fs/super.c:335 deactivate_super+0xbe/0xf0 fs/super.c:366 cleanup_mnt+0x45c/0x510 fs/namespace.c:1143 __cleanup_mnt+0x19/0x20 fs/namespace.c:1150 task_work_run+0x129/0x190 kernel/task_work.c:164 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop+0xc4/0xe0 kernel/entry/common.c:181 exit_to_user_mode_prepare+0x5a/0xa0 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x26/0x160 kernel/entry/common.c:307 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 The buggy address belongs to the object at ffff888123c5c4b0 which belongs to the cache kernfs_node_cache of size 136 The buggy address is located 0 bytes inside of 136-byte region [ffff888123c5c4b0, ffff888123c5c538) The buggy address belongs to the page: page:ffffea00048f1700 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x123c5c flags: 0x4000000000000200(slab|zone=1) raw: 4000000000000200 0000000000000000 0000000100000001 ffff8881001cdc80 raw: 0000000000000000 0000000000140014 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 288, ts 20389352542, free_ts 0 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x1a3/0x1b0 mm/page_alloc.c:2605 prep_new_page+0x1b/0x110 mm/page_alloc.c:2611 get_page_from_freelist+0x3550/0x35d0 mm/page_alloc.c:4485 __alloc_pages+0x27e/0x8f0 mm/page_alloc.c:5779 allocate_slab mm/slub.c:1932 [inline] new_slab+0x9a/0x4e0 mm/slub.c:1995 ___slab_alloc+0x39e/0x830 mm/slub.c:3028 __slab_alloc+0x4a/0x90 mm/slub.c:3115 slab_alloc_node mm/slub.c:3206 [inline] slab_alloc mm/slub.c:3248 [inline] kmem_cache_alloc+0x134/0x200 mm/slub.c:3253 kmem_cache_zalloc include/linux/slab.h:723 [inline] __kernfs_new_node+0xdb/0x700 fs/kernfs/dir.c:593 kernfs_new_node+0x130/0x230 fs/kernfs/dir.c:669 __kernfs_create_file+0x4a/0x270 fs/kernfs/file.c:987 sysfs_add_file_mode_ns+0x273/0x320 fs/sysfs/file.c:317 create_files fs/sysfs/group.c:64 [inline] internal_create_group+0x573/0xf00 fs/sysfs/group.c:149 internal_create_groups fs/sysfs/group.c:189 [inline] sysfs_create_groups+0x5b/0x130 fs/sysfs/group.c:215 device_add_groups drivers/base/core.c:2498 [inline] device_add_attrs+0x13f/0x490 drivers/base/core.c:2657 device_add+0x5f7/0xf10 drivers/base/core.c:3370 page_owner free stack trace missing Memory state around the buggy address: ffff888123c5c380: fb fb fb fb fb fc fc fc fc fc fc fc fc fa fb fb ffff888123c5c400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc >ffff888123c5c480: fc fc fc fc fc fc fa fb fb fb fb fb fb fb fb fb ^ ffff888123c5c500: fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc 00 ffff888123c5c580: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ================================================================== general protection fault, probably for non-canonical address 0xf75ffc26c0000832: 0000 [#1] PREEMPT SMP KASAN KASAN: maybe wild-memory-access in range [0xbb00013600004190-0xbb00013600004197] CPU: 0 PID: 4414 Comm: kworker/0:8 Tainted: G B 5.15.156-syzkaller-00821-g29d153aabd54 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 Workqueue: events flush_stashed_error_work RIP: 0010:kernfs_root fs/kernfs/kernfs-internal.h:50 [inline] RIP: 0010:kernfs_find_and_get_ns+0x52/0x110 fs/kernfs/dir.c:884 Code: 08 48 89 f8 48 c1 e8 03 42 80 3c 30 00 74 05 e8 64 39 d5 ff 49 8b 5d 08 48 85 db 49 0f 44 dd 48 83 c3 50 48 89 d8 48 c1 e8 03 <42> 80 3c 30 00 74 08 48 89 df e8 3f 39 d5 ff 4c 8b 33 49 83 c6 68 RSP: 0018:ffffc90000ca7c58 EFLAGS: 00010a03 RAX: 17600026c0000832 RBX: bb00013600004194 RCX: ffffffff81dd73ec RDX: 0000000000000000 RSI: 0000000000000292 RDI: ffff888123c5c4b8 RBP: ffffc90000ca7c80 R08: dffffc0000000000 R09: 0000000000000003 R10: ffffed102478b896 R11: dffffc0000000001 R12: ffffffff858effa0 R13: ffff888123c5c4b0 R14: dffffc0000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b30013ff8 CR3: 000000010cece000 CR4: 00000000003506b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: kernfs_find_and_get include/linux/kernfs.h:574 [inline] sysfs_notify+0x73/0xd0 fs/sysfs/file.c:193 ext4_notify_error_sysfs+0x25/0x30 fs/ext4/sysfs.c:516 flush_stashed_error_work+0x302/0x320 process_one_work+0x6bb/0xc10 kernel/workqueue.c:2325 worker_thread+0xad5/0x12a0 kernel/workqueue.c:2472 kthread+0x421/0x510 kernel/kthread.c:337 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:300 Modules linked in: ---[ end trace eef95d7c4ecf91c9 ]--- RIP: 0010:kernfs_root fs/kernfs/kernfs-internal.h:50 [inline] RIP: 0010:kernfs_find_and_get_ns+0x52/0x110 fs/kernfs/dir.c:884 Code: 08 48 89 f8 48 c1 e8 03 42 80 3c 30 00 74 05 e8 64 39 d5 ff 49 8b 5d 08 48 85 db 49 0f 44 dd 48 83 c3 50 48 89 d8 48 c1 e8 03 <42> 80 3c 30 00 74 08 48 89 df e8 3f 39 d5 ff 4c 8b 33 49 83 c6 68 RSP: 0018:ffffc90000ca7c58 EFLAGS: 00010a03 RAX: 17600026c0000832 RBX: bb00013600004194 RCX: ffffffff81dd73ec RDX: 0000000000000000 RSI: 0000000000000292 RDI: ffff888123c5c4b8 RBP: ffffc90000ca7c80 R08: dffffc0000000000 R09: 0000000000000003 R10: ffffed102478b896 R11: dffffc0000000001 R12: ffffffff858effa0 R13: ffff888123c5c4b0 R14: dffffc0000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020404030 CR3: 000000011ebde000 CR4: 00000000003506b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 08 48 89 or %cl,-0x77(%rax) 3: f8 clc 4: 48 c1 e8 03 shr $0x3,%rax 8: 42 80 3c 30 00 cmpb $0x0,(%rax,%r14,1) d: 74 05 je 0x14 f: e8 64 39 d5 ff call 0xffd53978 14: 49 8b 5d 08 mov 0x8(%r13),%rbx 18: 48 85 db test %rbx,%rbx 1b: 49 0f 44 dd cmove %r13,%rbx 1f: 48 83 c3 50 add $0x50,%rbx 23: 48 89 d8 mov %rbx,%rax 26: 48 c1 e8 03 shr $0x3,%rax * 2a: 42 80 3c 30 00 cmpb $0x0,(%rax,%r14,1) <-- trapping instruction 2f: 74 08 je 0x39 31: 48 89 df mov %rbx,%rdi 34: e8 3f 39 d5 ff call 0xffd53978 39: 4c 8b 33 mov (%rbx),%r14 3c: 49 83 c6 68 add $0x68,%r14