================================================================== BUG: KASAN: slab-use-after-free in __lock_acquire+0xff/0x7c80 kernel/locking/lockdep.c:5005 Read of size 8 at addr ffff88807ede94b8 by task syz.2.1537/9925 CPU: 1 PID: 9925 Comm: syz.2.1537 Not tainted 6.6.101-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0xac/0x220 mm/kasan/report.c:468 kasan_report+0x117/0x150 mm/kasan/report.c:581 __lock_acquire+0xff/0x7c80 kernel/locking/lockdep.c:5005 lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xa8/0xf0 kernel/locking/spinlock.c:162 remove_wait_queue+0x24/0x120 kernel/sched/wait.c:54 p9_mux_poll_stop net/9p/trans_fd.c:167 [inline] p9_conn_destroy net/9p/trans_fd.c:908 [inline] p9_fd_close+0xa1/0x430 net/9p/trans_fd.c:944 p9_client_create+0xc26/0xf90 net/9p/client.c:1059 v9fs_session_init+0x1d8/0x1990 fs/9p/v9fs.c:410 v9fs_mount+0xc9/0xb40 fs/9p/vfs_super.c:123 legacy_get_tree+0xea/0x180 fs/fs_context.c:662 vfs_get_tree+0x8c/0x280 fs/super.c:1764 do_new_mount+0x24b/0xa40 fs/namespace.c:3371 do_mount fs/namespace.c:3711 [inline] __do_sys_mount fs/namespace.c:3920 [inline] __se_sys_mount+0x2da/0x3c0 fs/namespace.c:3897 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f3c10b8ebe9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f3c11a7e038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f3c10db5fa0 RCX: 00007f3c10b8ebe9 RDX: 0000200000000080 RSI: 0000200000000140 RDI: 0000000000000000 RBP: 00007f3c10c11e19 R08: 00002000000001c0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f3c10db6038 R14: 00007f3c10db5fa0 R15: 00007ffe9fe94ed8 Allocated by task 9305: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:374 [inline] __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:383 kmalloc include/linux/slab.h:600 [inline] kzalloc include/linux/slab.h:721 [inline] __comedi_device_postconfig_async drivers/comedi/drivers.c:666 [inline] __comedi_device_postconfig drivers/comedi/drivers.c:723 [inline] comedi_device_postconfig+0x496/0xc50 drivers/comedi/drivers.c:758 comedi_device_attach+0x533/0x660 drivers/comedi/drivers.c:1000 do_devconfig_ioctl drivers/comedi/comedi_fops.c:855 [inline] comedi_unlocked_ioctl+0x68d/0xf90 drivers/comedi/comedi_fops.c:2156 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:871 [inline] __se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Freed by task 9938: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x2e/0x50 mm/kasan/generic.c:522 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:236 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1806 [inline] slab_free_freelist_hook+0x130/0x1b0 mm/slub.c:1832 slab_free mm/slub.c:3816 [inline] __kmem_cache_free+0xba/0x1f0 mm/slub.c:3829 comedi_device_detach_cleanup drivers/comedi/drivers.c:171 [inline] comedi_device_detach+0x363/0x6f0 drivers/comedi/drivers.c:207 do_devconfig_ioctl drivers/comedi/comedi_fops.c:833 [inline] comedi_unlocked_ioctl+0xbd0/0xf90 drivers/comedi/comedi_fops.c:2156 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:871 [inline] __se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 The buggy address belongs to the object at ffff88807ede9400 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 184 bytes inside of freed 256-byte region [ffff88807ede9400, ffff88807ede9500) The buggy address belongs to the physical page: page:ffffea0001fb7a00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88807ede8c00 pfn:0x7ede8 head:ffffea0001fb7a00 order:1 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000840 ffff888017841b40 ffffea0001fc0790 ffffea0001fe1710 raw: ffff88807ede8c00 0000000000100007 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 1, migratetype Unmovable, gfp_mask 0x1d2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 5927, tgid 5926 (syz.2.27), ts 75144767945, free_ts 75104484162 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x1cd/0x210 mm/page_alloc.c:1554 prep_new_page mm/page_alloc.c:1561 [inline] get_page_from_freelist+0x195c/0x19f0 mm/page_alloc.c:3191 __alloc_pages+0x1e3/0x460 mm/page_alloc.c:4457 alloc_slab_page+0x5d/0x170 mm/slub.c:1876 allocate_slab mm/slub.c:2023 [inline] new_slab+0x87/0x2e0 mm/slub.c:2076 ___slab_alloc+0xc6d/0x12f0 mm/slub.c:3230 __slab_alloc mm/slub.c:3329 [inline] __slab_alloc_node mm/slub.c:3382 [inline] slab_alloc_node mm/slub.c:3475 [inline] __kmem_cache_alloc_node+0x1a2/0x260 mm/slub.c:3524 kmalloc_trace+0x2a/0xe0 mm/slab_common.c:1098 kmalloc include/linux/slab.h:600 [inline] udf_fiiter_find_entry+0x13f/0x640 fs/udf/namei.c:62 udf_rename+0x615/0xcc0 fs/udf/namei.c:832 vfs_rename+0xb96/0xec0 fs/namei.c:4872 do_renameat2+0x8a1/0xc70 fs/namei.c:5025 __do_sys_rename fs/namei.c:5071 [inline] __se_sys_rename fs/namei.c:5069 [inline] __x64_sys_rename+0x86/0x90 fs/namei.c:5069 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1154 [inline] free_unref_page_prepare+0x7ce/0x8e0 mm/page_alloc.c:2336 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2429 __slab_free+0x35e/0x410 mm/slub.c:3722 qlink_free mm/kasan/quarantine.c:166 [inline] qlist_free_all+0x75/0xe0 mm/kasan/quarantine.c:185 kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:305 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x6e/0x4d0 mm/slab.h:767 slab_alloc_node mm/slub.c:3485 [inline] __kmem_cache_alloc_node+0x13e/0x260 mm/slub.c:3524 __do_kmalloc_node mm/slab_common.c:1006 [inline] __kmalloc+0xa4/0x240 mm/slab_common.c:1020 kmalloc include/linux/slab.h:604 [inline] tomoyo_realpath_from_path+0xe3/0x5d0 security/tomoyo/realpath.c:251 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path2_perm+0x282/0x660 security/tomoyo/file.c:923 tomoyo_path_rename+0x142/0x190 security/tomoyo/tomoyo.c:299 security_path_rename+0x16c/0x200 security/security.c:1828 do_renameat2+0x685/0xc70 fs/namei.c:5012 __do_sys_rename fs/namei.c:5071 [inline] __se_sys_rename fs/namei.c:5069 [inline] __x64_sys_rename+0x86/0x90 fs/namei.c:5069 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 Memory state around the buggy address: ffff88807ede9380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88807ede9400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88807ede9480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807ede9500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88807ede9580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================