Hello, syzbot has tested the proposed patch but the reproducer is still triggering an issue: KASAN: slab-use-after-free Read in fsnotify Quota error (device loop0): do_check_range: Getting block 0 out of range 1-5 EXT4-fs error (device loop0): ext4_release_dquot:6905: comm kworker/u8:4: Failed to release dquot type 1 ================================================================== BUG: KASAN: slab-use-after-free in fsnotify+0x3e5/0x1f00 fs/notify/fsnotify.c:541 Read of size 8 at addr ffff88802d133300 by task kworker/u8:4/62 CPU: 0 PID: 62 Comm: kworker/u8:4 Not tainted 6.9.0-rc3-next-20240410-syzkaller-dirty #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Workqueue: events_unbound quota_release_workfn Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 print_address_description mm/kasan/report.c:377 [inline] print_report+0x169/0x550 mm/kasan/report.c:488 kasan_report+0x143/0x180 mm/kasan/report.c:601 fsnotify+0x3e5/0x1f00 fs/notify/fsnotify.c:541 fsnotify_sb_error include/linux/fsnotify.h:456 [inline] __ext4_error+0x255/0x3b0 fs/ext4/super.c:843 ext4_release_dquot+0x326/0x450 fs/ext4/super.c:6903 quota_release_workfn+0x39f/0x650 fs/quota/dquot.c:840 process_one_work kernel/workqueue.c:3218 [inline] process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3299 worker_thread+0x86d/0xd70 kernel/workqueue.c:3380 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 </TASK> Allocated by task 5511: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:370 [inline] __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:387 kasan_kmalloc include/linux/kasan.h:211 [inline] kmalloc_trace_noprof+0x19c/0x2b0 mm/slub.c:4109 kmalloc_noprof include/linux/slab.h:660 [inline] kzalloc_noprof include/linux/slab.h:775 [inline] fsnotify_attach_info_to_sb fs/notify/mark.c:600 [inline] fsnotify_add_mark_list fs/notify/mark.c:692 [inline] fsnotify_add_mark_locked+0x3b2/0xe60 fs/notify/mark.c:777 fanotify_add_new_mark fs/notify/fanotify/fanotify_user.c:1267 [inline] fanotify_add_mark+0xbbd/0x1330 fs/notify/fanotify/fanotify_user.c:1334 do_fanotify_mark+0xbcc/0xd90 fs/notify/fanotify/fanotify_user.c:1896 __do_sys_fanotify_mark fs/notify/fanotify/fanotify_user.c:1919 [inline] __se_sys_fanotify_mark fs/notify/fanotify/fanotify_user.c:1915 [inline] __x64_sys_fanotify_mark+0xb5/0xd0 fs/notify/fanotify/fanotify_user.c:1915 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 5442: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579 poison_slab_object+0xe0/0x150 mm/kasan/common.c:240 __kasan_slab_free+0x37/0x60 mm/kasan/common.c:256 kasan_slab_free include/linux/kasan.h:184 [inline] slab_free_hook mm/slub.c:2190 [inline] slab_free mm/slub.c:4393 [inline] kfree+0x149/0x350 mm/slub.c:4514 fsnotify_sb_delete+0x692/0x6f0 fs/notify/fsnotify.c:106 generic_shutdown_super+0xa5/0x2d0 fs/super.c:632 kill_block_super+0x44/0x90 fs/super.c:1675 ext4_kill_sb+0x68/0xa0 fs/ext4/super.c:7323 deactivate_locked_super+0xc4/0x130 fs/super.c:472 cleanup_mnt+0x426/0x4c0 fs/namespace.c:1267 task_work_run+0x24f/0x310 kernel/task_work.c:180 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x168/0x370 kernel/entry/common.c:218 do_syscall_64+0x102/0x240 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88802d133300 which belongs to the cache kmalloc-32 of size 32 The buggy address is located 0 bytes inside of freed 32-byte region [ffff88802d133300, ffff88802d133320) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88802d133180 pfn:0x2d133 flags: 0xfff80000000200(workingset|node=0|zone=1|lastcpupid=0xfff) page_type: 0xffffefff(slab) raw: 00fff80000000200 ffff888015041500 ffffea00007c7590 ffffea0001aa96d0 raw: ffff88802d133180 000000000040003d 00000001ffffefff 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 1, tgid 177503641 (swapper/0), ts 1, free_ts 13042593494 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1468 prep_new_page mm/page_alloc.c:1476 [inline] get_page_from_freelist+0x2ce2/0x2d90 mm/page_alloc.c:3438 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4696 __alloc_pages_node_noprof include/linux/gfp.h:244 [inline] alloc_pages_node_noprof include/linux/gfp.h:271 [inline] alloc_slab_page+0x5f/0x120 mm/slub.c:2259 allocate_slab+0x5a/0x2e0 mm/slub.c:2422 new_slab mm/slub.c:2475 [inline] ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3624 __slab_alloc+0x58/0xa0 mm/slub.c:3714 __slab_alloc_node mm/slub.c:3767 [inline] slab_alloc_node mm/slub.c:3945 [inline] __do_kmalloc_node mm/slub.c:4077 [inline] kmalloc_node_track_caller_noprof+0x286/0x440 mm/slub.c:4098 __do_krealloc mm/slab_common.c:1190 [inline] krealloc_noprof+0x7d/0x120 mm/slab_common.c:1223 add_sysfs_param+0x137/0x7f0 kernel/params.c:663 kernel_add_sysfs_param+0xb4/0x130 kernel/params.c:817 param_sysfs_builtin+0x16e/0x1f0 kernel/params.c:856 param_sysfs_builtin_init+0x31/0x40 kernel/params.c:990 do_one_initcall+0x248/0x880 init/main.c:1263 do_initcall_level+0x157/0x210 init/main.c:1325 do_initcalls+0x3f/0x80 init/main.c:1341 page last free pid 782 tgid 782 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1088 [inline] free_unref_page+0xd22/0xea0 mm/page_alloc.c:2601 vfree+0x186/0x2e0 mm/vmalloc.c:3338 delayed_vfree_work+0x56/0x80 mm/vmalloc.c:3259 process_one_work kernel/workqueue.c:3218 [inline] process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3299 worker_thread+0x86d/0xd70 kernel/workqueue.c:3380 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Memory state around the buggy address: ffff88802d133200: 00 00 00 00 fc fc fc fc 00 00 00 00 fc fc fc fc ffff88802d133280: 00 00 00 00 fc fc fc fc 00 00 00 00 fc fc fc fc >ffff88802d133300: fa fb fb fb fc fc fc fc 00 00 00 00 fc fc fc fc ^ ffff88802d133380: 00 00 00 fc fc fc fc fc 00 00 00 04 fc fc fc fc ffff88802d133400: 00 00 00 fc fc fc fc fc 00 00 00 00 fc fc fc fc ================================================================== Tested on: commit: 6ebf211b Add linux-next specific files for 20240410 git tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git console output: https://syzkaller.appspot.com/x/log.txt?x=10c3ac7d180000 kernel config: https://syzkaller.appspot.com/x/.config?x=16ca158ef7e08662 dashboard link: https://syzkaller.appspot.com/bug?extid=5e3f9b2a67b45f16d4e6 compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 patch: https://syzkaller.appspot.com/x/patch.diff?x=165b0243180000