================================================================== BUG: KASAN: slab-use-after-free in instrument_atomic_read_write include/linux/instrumented.h:112 [inline] BUG: KASAN: slab-use-after-free in atomic_dec_and_test include/linux/atomic/atomic-instrumented.h:1383 [inline] BUG: KASAN: slab-use-after-free in gfs2_qd_dealloc+0x81/0xe0 fs/gfs2/quota.c:112 Write of size 4 at addr ffff88807ee54b68 by task udevd/5194 CPU: 1 UID: 0 PID: 5194 Comm: udevd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xba/0x230 mm/kasan/report.c:482 kasan_report+0x117/0x150 mm/kasan/report.c:595 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x264/0x2c0 mm/kasan/generic.c:200 instrument_atomic_read_write include/linux/instrumented.h:112 [inline] atomic_dec_and_test include/linux/atomic/atomic-instrumented.h:1383 [inline] gfs2_qd_dealloc+0x81/0xe0 fs/gfs2/quota.c:112 rcu_do_batch kernel/rcu/tree.c:2617 [inline] rcu_core+0x7cd/0x1070 kernel/rcu/tree.c:2869 handle_softirqs+0x22a/0x7c0 kernel/softirq.c:626 __do_softirq kernel/softirq.c:660 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:727 irq_exit_rcu+0x9/0x30 kernel/softirq.c:743 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:188 [inline] RIP: 0010:_raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:202 Code: 90 f3 0f 1e fa 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 0a 92 1d f6 48 89 df e8 52 06 1e f6 e8 dd 4d 48 f6 fb bf 01 00 00 00 d2 04 10 f6 65 8b 05 db b7 70 07 85 c0 74 07 5b e9 81 48 00 00 RSP: 0018:ffffc90003077bf0 EFLAGS: 00000202 RAX: 00000000000fc907 RBX: ffff88807dc64d40 RCX: 0000000080000001 RDX: 0000000000000000 RSI: ffffffff8dce9260 RDI: 0000000000000001 RBP: ffffc90003077df0 R08: ffffffff8fefddb7 R09: 1ffffffff1fdfbb6 R10: dffffc0000000000 R11: fffffbfff1fdfbb7 R12: dffffc0000000000 R13: ffff88807ea18018 R14: ffffc90003077d38 R15: ffff88807dc64cd0 spin_unlock_irq include/linux/spinlock.h:404 [inline] ep_poll fs/eventpoll.c:2024 [inline] do_epoll_wait+0xcac/0xf60 fs/eventpoll.c:2461 __do_sys_epoll_wait fs/eventpoll.c:2469 [inline] __se_sys_epoll_wait fs/eventpoll.c:2464 [inline] __x64_sys_epoll_wait+0x1d7/0x230 fs/eventpoll.c:2464 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7faea38a7407 Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff RSP: 002b:00007fff89823880 EFLAGS: 00000202 ORIG_RAX: 00000000000000e8 RAX: ffffffffffffffda RBX: 00007faea3fde880 RCX: 00007faea38a7407 RDX: 0000000000000008 RSI: 00007fff898239e0 RDI: 000000000000000b RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000bb8 R11: 0000000000000202 R12: 0000000000000000 R13: 0000556922462100 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 6199: 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+0x31c/0x660 mm/slub.c:5244 kmalloc_noprof include/linux/slab.h:962 [inline] kzalloc_noprof include/linux/slab.h:1204 [inline] init_sbd fs/gfs2/ops_fstype.c:79 [inline] gfs2_fill_super+0x128/0x21d0 fs/gfs2/ops_fstype.c:1121 get_tree_bdev_flags+0x431/0x4f0 fs/super.c:1694 gfs2_get_tree+0x51/0x1e0 fs/gfs2/ops_fstype.c:1332 vfs_get_tree+0x92/0x2a0 fs/super.c:1754 fc_mount fs/namespace.c:1193 [inline] do_new_mount_fc fs/namespace.c:3760 [inline] do_new_mount+0x341/0xd30 fs/namespace.c:3836 do_mount fs/namespace.c:4159 [inline] __do_sys_mount fs/namespace.c:4348 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4325 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 6199: 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:2621 [inline] slab_free mm/slub.c:6026 [inline] kfree+0x1c1/0x610 mm/slub.c:6339 free_sbd fs/gfs2/ops_fstype.c:72 [inline] gfs2_fill_super+0x150e/0x21d0 fs/gfs2/ops_fstype.c:1316 get_tree_bdev_flags+0x431/0x4f0 fs/super.c:1694 gfs2_get_tree+0x51/0x1e0 fs/gfs2/ops_fstype.c:1332 vfs_get_tree+0x92/0x2a0 fs/super.c:1754 fc_mount fs/namespace.c:1193 [inline] do_new_mount_fc fs/namespace.c:3760 [inline] do_new_mount+0x341/0xd30 fs/namespace.c:3836 do_mount fs/namespace.c:4159 [inline] __do_sys_mount fs/namespace.c:4348 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4325 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88807ee54000 which belongs to the cache kmalloc-8k of size 8192 The buggy address is located 2920 bytes inside of freed 8192-byte region [ffff88807ee54000, ffff88807ee56000) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7ee50 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 ffff88801b027280 dead000000000100 dead000000000122 raw: 0000000000000000 0000000000020002 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801b027280 dead000000000100 dead000000000122 head: 0000000000000000 0000000000020002 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea0001fb9401 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 0xd2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5849, tgid 5849 (sh), ts 320913974016, free_ts 320680860609 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x231/0x280 mm/page_alloc.c:1883 prep_new_page mm/page_alloc.c:1891 [inline] get_page_from_freelist+0x24dc/0x2580 mm/page_alloc.c:3956 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5244 alloc_slab_page mm/slub.c:3189 [inline] allocate_slab+0x7b/0x660 mm/slub.c:3362 new_slab mm/slub.c:3420 [inline] refill_objects+0x33a/0x3d0 mm/slub.c:7028 refill_sheaf mm/slub.c:2738 [inline] __pcs_replace_empty_main+0x2b9/0x620 mm/slub.c:4483 alloc_from_pcs mm/slub.c:4586 [inline] slab_alloc_node mm/slub.c:4720 [inline] __kmalloc_cache_noprof+0x392/0x660 mm/slub.c:5239 kmalloc_noprof include/linux/slab.h:962 [inline] kzalloc_noprof include/linux/slab.h:1204 [inline] tomoyo_print_bprm security/tomoyo/audit.c:26 [inline] tomoyo_init_log+0x112e/0x1fb0 security/tomoyo/audit.c:264 tomoyo_supervisor+0x353/0x1570 security/tomoyo/common.c:2232 tomoyo_audit_env_log security/tomoyo/environ.c:37 [inline] tomoyo_env_perm+0x151/0x1f0 security/tomoyo/environ.c:64 tomoyo_environ security/tomoyo/domain.c:673 [inline] tomoyo_find_next_domain+0x15cb/0x1aa0 security/tomoyo/domain.c:889 tomoyo_bprm_check_security+0x11b/0x180 security/tomoyo/tomoyo.c:102 security_bprm_check+0x85/0x240 security/security.c:794 search_binary_handler fs/exec.c:1654 [inline] exec_binprm fs/exec.c:1696 [inline] bprm_execve+0x896/0x1410 fs/exec.c:1748 do_execveat_common+0x50d/0x690 fs/exec.c:1846 __do_sys_execve fs/exec.c:1930 [inline] __se_sys_execve fs/exec.c:1924 [inline] __x64_sys_execve+0x97/0xc0 fs/exec.c:1924 page last free pid 5847 tgid 5847 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1432 [inline] __free_frozen_pages+0xbb9/0xd10 mm/page_alloc.c:2972 __slab_free+0x263/0x2b0 mm/slub.c:5437 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:4406 [inline] slab_alloc_node mm/slub.c:4735 [inline] __kmalloc_cache_noprof+0x2ba/0x660 mm/slub.c:5239 kmalloc_noprof include/linux/slab.h:962 [inline] kzalloc_noprof include/linux/slab.h:1204 [inline] seccomp_prepare_filter kernel/seccomp.c:696 [inline] seccomp_prepare_user_filter kernel/seccomp.c:738 [inline] seccomp_set_mode_filter kernel/seccomp.c:1990 [inline] do_seccomp+0x75d/0xdd0 kernel/seccomp.c:2110 __do_sys_prctl kernel/sys.c:2625 [inline] __se_sys_prctl+0x38a/0x1a60 kernel/sys.c:2533 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff88807ee54a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807ee54a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88807ee54b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807ee54b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807ee54c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 90 nop 1: f3 0f 1e fa endbr64 5: 53 push %rbx 6: 48 89 fb mov %rdi,%rbx 9: 48 83 c7 18 add $0x18,%rdi d: 48 8b 74 24 08 mov 0x8(%rsp),%rsi 12: e8 0a 92 1d f6 call 0xf61d9221 17: 48 89 df mov %rbx,%rdi 1a: e8 52 06 1e f6 call 0xf61e0671 1f: e8 dd 4d 48 f6 call 0xf6484e01 24: fb sti 25: bf 01 00 00 00 mov $0x1,%edi * 2a: e8 d2 04 10 f6 call 0xf6100501 <-- trapping instruction 2f: 65 8b 05 db b7 70 07 mov %gs:0x770b7db(%rip),%eax # 0x770b811 36: 85 c0 test %eax,%eax 38: 74 07 je 0x41 3a: 5b pop %rbx 3b: e9 81 48 00 00 jmp 0x48c1