================================================================== BUG: KASAN: slab-use-after-free in instrument_atomic_read include/linux/instrumented.h:82 [inline] BUG: KASAN: slab-use-after-free in _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] BUG: KASAN: slab-use-after-free in gfs2_withdrawn fs/gfs2/util.h:187 [inline] BUG: KASAN: slab-use-after-free in gfs2_quotad+0x19c/0x930 fs/gfs2/quota.c:1587 Read of size 8 at addr ffff88803f3380a8 by task gfs2_quotad/syz/15021 CPU: 1 UID: 0 PID: 15021 Comm: gfs2_quotad/syz Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x240 mm/kasan/report.c:482 kasan_report+0x118/0x150 mm/kasan/report.c:595 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x2b0/0x2c0 mm/kasan/generic.c:200 instrument_atomic_read include/linux/instrumented.h:82 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] gfs2_withdrawn fs/gfs2/util.h:187 [inline] gfs2_quotad+0x19c/0x930 fs/gfs2/quota.c:1587 kthread+0x389/0x480 kernel/kthread.c:467 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 15004: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __kmalloc_cache_noprof+0x3e2/0x700 mm/slub.c:6017 kmalloc_noprof include/linux/slab.h:968 [inline] kzalloc_noprof include/linux/slab.h:1210 [inline] init_sbd fs/gfs2/ops_fstype.c:79 [inline] gfs2_fill_super+0x11f/0x21b0 fs/gfs2/ops_fstype.c:1121 get_tree_bdev_flags+0x40e/0x4d0 fs/super.c:1691 gfs2_get_tree+0x51/0x1e0 fs/gfs2/ops_fstype.c:1332 vfs_get_tree+0x92/0x2a0 fs/super.c:1751 fc_mount fs/namespace.c:1204 [inline] do_new_mount_fc fs/namespace.c:3763 [inline] do_new_mount+0x31a/0xcf0 fs/namespace.c:3839 do_mount fs/namespace.c:4162 [inline] __do_sys_mount fs/namespace.c:4351 [inline] __se_sys_mount+0x313/0x410 fs/namespace.c:4328 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 15004: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2768 [inline] slab_free mm/slub.c:6911 [inline] kfree+0x1be/0x670 mm/slub.c:7209 free_sbd fs/gfs2/ops_fstype.c:72 [inline] gfs2_fill_super+0x14ef/0x21b0 fs/gfs2/ops_fstype.c:1316 get_tree_bdev_flags+0x40e/0x4d0 fs/super.c:1691 gfs2_get_tree+0x51/0x1e0 fs/gfs2/ops_fstype.c:1332 vfs_get_tree+0x92/0x2a0 fs/super.c:1751 fc_mount fs/namespace.c:1204 [inline] do_new_mount_fc fs/namespace.c:3763 [inline] do_new_mount+0x31a/0xcf0 fs/namespace.c:3839 do_mount fs/namespace.c:4162 [inline] __do_sys_mount fs/namespace.c:4351 [inline] __se_sys_mount+0x313/0x410 fs/namespace.c:4328 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88803f338000 which belongs to the cache kmalloc-8k of size 8192 The buggy address is located 168 bytes inside of freed 8192-byte region [ffff88803f338000, ffff88803f33a000) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x3f338 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88813fea7280 ffffea00007ccc00 0000000000000006 raw: 0000000000000000 0000000080020002 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88813fea7280 ffffea00007ccc00 0000000000000006 head: 0000000000000000 0000000080020002 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea0000fcce01 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008 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 14686, tgid 14677 (syz.7.1618), ts 1102528006462, free_ts 1102524399834 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x23d/0x2a0 mm/page_alloc.c:1887 prep_new_page mm/page_alloc.c:1895 [inline] get_page_from_freelist+0x23a5/0x2440 mm/page_alloc.c:3948 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5236 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2486 alloc_slab_page mm/slub.c:3303 [inline] allocate_slab+0x87/0x670 mm/slub.c:3478 new_slab mm/slub.c:3536 [inline] ___slab_alloc+0xdb6/0x17b0 mm/slub.c:4890 __slab_alloc+0x65/0x100 mm/slub.c:5013 __slab_alloc_node mm/slub.c:5089 [inline] slab_alloc_node mm/slub.c:5488 [inline] __kmalloc_cache_noprof+0x41e/0x700 mm/slub.c:6012 kmalloc_noprof include/linux/slab.h:968 [inline] audit_log_d_path+0xb8/0x1a0 kernel/audit.c:2197 audit_log_d_path_exe+0x42/0x70 kernel/audit.c:2413 audit_log_task+0x2b3/0x3c0 kernel/auditsc.c:2904 audit_seccomp+0x86/0x190 kernel/auditsc.c:2951 seccomp_log kernel/seccomp.c:1048 [inline] __seccomp_filter+0xcf0/0x1e20 kernel/seccomp.c:1344 syscall_trace_enter+0xaa/0x160 kernel/entry/syscall-common.c:44 syscall_enter_from_user_mode_work include/linux/entry-common.h:78 [inline] syscall_enter_from_user_mode include/linux/entry-common.h:109 [inline] do_syscall_64+0xc5/0xf80 arch/x86/entry/syscall_64.c:90 entry_SYSCALL_64_after_hwframe+0x77/0x7f page last free pid 5200 tgid 5200 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1436 [inline] __free_frozen_pages+0xb99/0xd10 mm/page_alloc.c:2976 __slab_free+0x2ce/0x320 mm/slub.c:6245 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:5187 [inline] slab_alloc_node mm/slub.c:5500 [inline] __kmalloc_cache_noprof+0x37c/0x700 mm/slub.c:6012 kmalloc_noprof include/linux/slab.h:968 [inline] kzalloc_noprof include/linux/slab.h:1210 [inline] kernfs_fop_open+0x397/0xca0 fs/kernfs/file.c:641 do_dentry_open+0x785/0x14e0 fs/open.c:949 vfs_open+0x3b/0x340 fs/open.c:1081 do_open fs/namei.c:4669 [inline] path_openat+0x2de0/0x3840 fs/namei.c:4828 do_file_open+0x203/0x440 fs/namei.c:4857 do_sys_openat2+0x105/0x1e0 fs/open.c:1366 do_sys_open fs/open.c:1372 [inline] __do_sys_openat fs/open.c:1388 [inline] __se_sys_openat fs/open.c:1383 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1383 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff88803f337f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88803f338000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88803f338080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88803f338100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88803f338180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================