================================================================== 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:525 Read of size 4 at addr ffff88812e6e0898 by task kworker/1:3/405 CPU: 1 PID: 405 Comm: kworker/1:3 Not tainted 6.1.124-syzkaller-00004-g1ac09f5c0571 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Workqueue: events flush_stashed_error_work Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x151/0x1b7 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:316 [inline] print_report+0x158/0x4e0 mm/kasan/report.c:427 kasan_report+0x13c/0x170 mm/kasan/report.c:531 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:350 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:525 sysfs_notify+0x9a/0xd0 fs/sysfs/file.c:187 ext4_notify_error_sysfs+0x25/0x30 fs/ext4/sysfs.c:518 flush_stashed_error_work+0x2fe/0x320 process_one_work+0x73d/0xcb0 kernel/workqueue.c:2299 worker_thread+0xa60/0x1260 kernel/workqueue.c:2446 kthread+0x26d/0x300 kernel/kthread.c:386 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Allocated by task 1063: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 kasan_save_alloc_info+0x1f/0x30 mm/kasan/generic.c:505 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:333 kasan_slab_alloc include/linux/kasan.h:202 [inline] slab_post_alloc_hook+0x53/0x2c0 mm/slab.h:768 slab_alloc_node mm/slub.c:3421 [inline] slab_alloc mm/slub.c:3431 [inline] __kmem_cache_alloc_lru mm/slub.c:3438 [inline] kmem_cache_alloc+0x175/0x320 mm/slub.c:3447 kmem_cache_zalloc include/linux/slab.h:689 [inline] __kernfs_new_node+0xdb/0x700 fs/kernfs/dir.c:614 kernfs_new_node+0x130/0x230 fs/kernfs/dir.c:690 kernfs_create_dir_ns+0x44/0x130 fs/kernfs/dir.c:1046 sysfs_create_dir_ns+0x185/0x390 fs/sysfs/dir.c:59 create_dir lib/kobject.c:63 [inline] kobject_add_internal+0x635/0xbf0 lib/kobject.c:231 kobject_add_varg lib/kobject.c:366 [inline] kobject_init_and_add+0x120/0x190 lib/kobject.c:449 ext4_register_sysfs+0xbf/0x2c0 fs/ext4/sysfs.c:531 __ext4_fill_super fs/ext4/super.c:5484 [inline] ext4_fill_super+0x7927/0x8450 fs/ext4/super.c:5640 get_tree_bdev+0x440/0x680 fs/super.c:1368 ext4_get_tree+0x1c/0x20 fs/ext4/super.c:5670 vfs_get_tree+0x88/0x290 fs/super.c:1575 do_new_mount+0x2ba/0xb30 fs/namespace.c:3056 path_mount+0x671/0x1070 fs/namespace.c:3386 do_mount fs/namespace.c:3399 [inline] __do_sys_mount fs/namespace.c:3607 [inline] __se_sys_mount+0x2c4/0x3b0 fs/namespace.c:3584 __x64_sys_mount+0xbf/0xd0 fs/namespace.c:3584 x64_sys_call+0x49d/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:166 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Freed by task 386: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:516 ____kasan_slab_free+0x131/0x180 mm/kasan/common.c:241 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:249 kasan_slab_free include/linux/kasan.h:178 [inline] slab_free_hook mm/slub.c:1745 [inline] slab_free_freelist_hook mm/slub.c:1771 [inline] slab_free mm/slub.c:3686 [inline] kmem_cache_free+0x291/0x560 mm/slub.c:3711 kernfs_put+0x392/0x520 fs/kernfs/dir.c:568 sysfs_put include/linux/sysfs.h:657 [inline] __kobject_del+0x10f/0x300 lib/kobject.c:597 kobject_del+0x45/0x60 lib/kobject.c:619 ext4_unregister_sysfs+0x91/0xa0 fs/ext4/sysfs.c:565 ext4_put_super+0x7d/0xd60 fs/ext4/super.c:1216 generic_shutdown_super+0x14f/0x370 fs/super.c:503 kill_block_super+0x7e/0xe0 fs/super.c:1472 deactivate_locked_super+0xad/0x110 fs/super.c:334 deactivate_super+0xbe/0xf0 fs/super.c:365 cleanup_mnt+0x485/0x510 fs/namespace.c:1186 __cleanup_mnt+0x19/0x20 fs/namespace.c:1193 task_work_run+0x24d/0x2e0 kernel/task_work.c:203 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0x94/0xa0 kernel/entry/common.c:177 exit_to_user_mode_prepare+0x5a/0xa0 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x26/0x130 kernel/entry/common.c:303 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 The buggy address belongs to the object at ffff88812e6e0898 which belongs to the cache kernfs_node_cache of size 136 The buggy address is located 0 bytes inside of 136-byte region [ffff88812e6e0898, ffff88812e6e0920) The buggy address belongs to the physical page: page:ffffea0004b9b800 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x12e6e0 flags: 0x4000000000000200(slab|zone=1) raw: 4000000000000200 0000000000000000 dead000000000001 ffff8881002ab500 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 0x112cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY), pid 342, tgid 342 (syz-executor), ts 37562152249, free_ts 0 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x213/0x220 mm/page_alloc.c:2605 prep_new_page+0x1b/0x110 mm/page_alloc.c:2612 get_page_from_freelist+0x2f41/0x2fc0 mm/page_alloc.c:4477 __alloc_pages+0x234/0x610 mm/page_alloc.c:5775 alloc_slab_page+0x6c/0xf0 allocate_slab mm/slub.c:1962 [inline] new_slab+0x90/0x3e0 mm/slub.c:2015 ___slab_alloc+0x6f9/0xb80 mm/slub.c:3203 __slab_alloc+0x5d/0xa0 mm/slub.c:3302 slab_alloc_node mm/slub.c:3387 [inline] slab_alloc mm/slub.c:3431 [inline] __kmem_cache_alloc_lru mm/slub.c:3438 [inline] kmem_cache_alloc+0x1be/0x320 mm/slub.c:3447 kmem_cache_zalloc include/linux/slab.h:689 [inline] __kernfs_new_node+0xdb/0x700 fs/kernfs/dir.c:614 kernfs_new_node+0x130/0x230 fs/kernfs/dir.c:690 kernfs_create_link+0xba/0x210 fs/kernfs/symlink.c:39 sysfs_do_create_link_sd+0x89/0x110 fs/sysfs/symlink.c:44 sysfs_do_create_link fs/sysfs/symlink.c:80 [inline] sysfs_create_link+0x68/0x80 fs/sysfs/symlink.c:92 netdev_adjacent_sysfs_add net/core/dev.c:7496 [inline] __netdev_adjacent_dev_insert+0x439/0x7e0 net/core/dev.c:7552 __netdev_adjacent_dev_link_lists net/core/dev.c:7634 [inline] __netdev_adjacent_dev_link_neighbour net/core/dev.c:7658 [inline] __netdev_upper_dev_link+0x535/0x750 net/core/dev.c:7718 page_owner free stack trace missing Memory state around the buggy address: ffff88812e6e0780: fb fb fc fc fc fc fc fc fc fc 00 00 00 00 00 00 ffff88812e6e0800: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc >ffff88812e6e0880: fc fc fc fa fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88812e6e0900: fb fb fb fb fc fc fc fc fc fc fc fc 00 00 00 00 ffff88812e6e0980: 00 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc ================================================================== general protection fault, probably for non-canonical address 0xe0e8bc2c4000003a: 0000 [#1] PREEMPT SMP KASAN KASAN: maybe wild-memory-access in range [0x07460162000001d0-0x07460162000001d7] CPU: 1 PID: 405 Comm: kworker/1:3 Tainted: G B 6.1.124-syzkaller-00004-g1ac09f5c0571 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Workqueue: events flush_stashed_error_work RIP: 0010:kernfs_root fs/kernfs/kernfs-internal.h:68 [inline] RIP: 0010:kernfs_find_and_get_ns+0x52/0x110 fs/kernfs/dir.c:903 Code: 08 48 89 f8 48 c1 e8 03 42 80 3c 30 00 74 05 e8 c4 c1 d3 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 9f c1 d3 ff 4c 8b 33 49 83 c6 60 RSP: 0018:ffffc90000a37c68 EFLAGS: 00010206 RAX: 00e8c02c4000003a RBX: 07460162000001d2 RCX: ffffffff81e9593c RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff88812e6e08a0 RBP: ffffc90000a37c90 R08: dffffc0000000000 R09: 0000000000000003 R10: ffffffffffffffff R11: dffffc0000000001 R12: ffffffff85d4d860 R13: ffff88812e6e0898 R14: dffffc0000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555589a384a8 CR3: 00000001252c8000 CR4: 00000000003506a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: kernfs_find_and_get include/linux/kernfs.h:614 [inline] sysfs_notify+0x73/0xd0 fs/sysfs/file.c:190 ext4_notify_error_sysfs+0x25/0x30 fs/ext4/sysfs.c:518 flush_stashed_error_work+0x2fe/0x320 process_one_work+0x73d/0xcb0 kernel/workqueue.c:2299 worker_thread+0xa60/0x1260 kernel/workqueue.c:2446 kthread+0x26d/0x300 kernel/kthread.c:386 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:kernfs_root fs/kernfs/kernfs-internal.h:68 [inline] RIP: 0010:kernfs_find_and_get_ns+0x52/0x110 fs/kernfs/dir.c:903 Code: 08 48 89 f8 48 c1 e8 03 42 80 3c 30 00 74 05 e8 c4 c1 d3 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 9f c1 d3 ff 4c 8b 33 49 83 c6 60 RSP: 0018:ffffc90000a37c68 EFLAGS: 00010206 RAX: 00e8c02c4000003a RBX: 07460162000001d2 RCX: ffffffff81e9593c RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff88812e6e08a0 RBP: ffffc90000a37c90 R08: dffffc0000000000 R09: 0000000000000003 R10: ffffffffffffffff R11: dffffc0000000001 R12: ffffffff85d4d860 R13: ffff88812e6e0898 R14: dffffc0000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555589a384a8 CR3: 00000001252c8000 CR4: 00000000003506a0 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 c4 c1 d3 ff call 0xffd3c1d8 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 9f c1 d3 ff call 0xffd3c1d8 39: 4c 8b 33 mov (%rbx),%r14 3c: 49 83 c6 60 add $0x60,%r14