BTRFS: device fsid 395ef67a-297e-477c-816d-cd80a5b93e5d devid 1 transid 8 /dev/loop4 (7:4) scanned by syz.4.1653 (13134) ================================================================== BUG: KASAN: slab-use-after-free in close_fs_devices+0x81f/0x870 fs/btrfs/volumes.c:1182 Read of size 4 at addr ffff8880295c2d30 by task syz.4.1653/13134 CPU: 0 UID: 0 PID: 13134 Comm: syz.4.1653 Not tainted 6.16.0-rc3-next-20250627-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:408 [inline] print_report+0xd2/0x2b0 mm/kasan/report.c:521 kasan_report+0x118/0x150 mm/kasan/report.c:634 close_fs_devices+0x81f/0x870 fs/btrfs/volumes.c:1182 btrfs_close_devices+0xc5/0x560 fs/btrfs/volumes.c:1201 btrfs_free_fs_info+0x4f/0x3c0 fs/btrfs/disk-io.c:1250 deactivate_locked_super+0xb9/0x130 fs/super.c:474 btrfs_get_tree_super fs/btrfs/super.c:-1 [inline] btrfs_get_tree_subvol fs/btrfs/super.c:2073 [inline] btrfs_get_tree+0xd1e/0x17f0 fs/btrfs/super.c:2107 vfs_get_tree+0x8f/0x2b0 fs/super.c:1804 do_new_mount+0x24a/0xa40 fs/namespace.c:3902 do_mount fs/namespace.c:4239 [inline] __do_sys_mount fs/namespace.c:4450 [inline] __se_sys_mount+0x317/0x410 fs/namespace.c:4427 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd120f900ca Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 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:00007fd121d7ce68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fd121d7cef0 RCX: 00007fd120f900ca RDX: 0000200000000200 RSI: 0000200000005600 RDI: 00007fd121d7ceb0 RBP: 0000200000000200 R08: 00007fd121d7cef0 R09: 0000000000000800 R10: 0000000000000800 R11: 0000000000000246 R12: 0000200000005600 R13: 00007fd121d7ceb0 R14: 000000000000559e R15: 0000200000000740 Allocated by task 13134: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __kmalloc_cache_noprof+0x230/0x3d0 mm/slub.c:4396 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] alloc_fs_devices+0x4f/0x1d0 fs/btrfs/volumes.c:384 device_list_add+0x6b7/0x20b0 fs/btrfs/volumes.c:813 btrfs_scan_one_device+0x3fd/0x5b0 fs/btrfs/volumes.c:1487 btrfs_get_tree_super fs/btrfs/super.c:1856 [inline] btrfs_get_tree_subvol fs/btrfs/super.c:2073 [inline] btrfs_get_tree+0x433/0x17f0 fs/btrfs/super.c:2107 vfs_get_tree+0x8f/0x2b0 fs/super.c:1804 do_new_mount+0x24a/0xa40 fs/namespace.c:3902 do_mount fs/namespace.c:4239 [inline] __do_sys_mount fs/namespace.c:4450 [inline] __se_sys_mount+0x317/0x410 fs/namespace.c:4427 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 8457: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x62/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2417 [inline] slab_free mm/slub.c:4680 [inline] kfree+0x18e/0x440 mm/slub.c:4879 btrfs_free_stale_devices+0x61c/0x6b0 fs/btrfs/volumes.c:564 btrfs_scan_one_device+0x3d5/0x5b0 fs/btrfs/volumes.c:1481 btrfs_control_ioctl+0x11f/0x360 fs/btrfs/super.c:2256 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff8880295c2c00 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 304 bytes inside of freed 512-byte region [ffff8880295c2c00, ffff8880295c2e00) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x295c0 head: order:2 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 ffff88801a441c80 ffffea0000cb7b00 dead000000000002 raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801a441c80 ffffea0000cb7b00 dead000000000002 head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000002 ffffea0000a57001 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5487, tgid 5487 (run-parts), ts 56441151828, free_ts 56419870018 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1848 prep_new_page mm/page_alloc.c:1856 [inline] get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3855 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5145 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2419 alloc_slab_page mm/slub.c:2487 [inline] allocate_slab+0x8a/0x370 mm/slub.c:2655 new_slab mm/slub.c:2709 [inline] ___slab_alloc+0xbeb/0x1410 mm/slub.c:3891 __slab_alloc mm/slub.c:3981 [inline] __slab_alloc_node mm/slub.c:4056 [inline] slab_alloc_node mm/slub.c:4217 [inline] __do_kmalloc_node mm/slub.c:4364 [inline] __kmalloc_noprof+0x305/0x4f0 mm/slub.c:4377 kmalloc_noprof include/linux/slab.h:909 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] tomoyo_init_log+0x1a6e/0x1f70 security/tomoyo/audit.c:275 tomoyo_supervisor+0x340/0x1480 security/tomoyo/common.c:2198 tomoyo_audit_path_log security/tomoyo/file.c:168 [inline] tomoyo_path_permission+0x25a/0x380 security/tomoyo/file.c:587 tomoyo_check_open_permission+0x24d/0x3b0 security/tomoyo/file.c:777 security_file_open+0xb1/0x270 security/security.c:3114 do_dentry_open+0x35e/0x1970 fs/open.c:941 vfs_open+0x3b/0x340 fs/open.c:1094 do_open fs/namei.c:3887 [inline] path_openat+0x2ee5/0x3830 fs/namei.c:4046 do_filp_open+0x1fa/0x410 fs/namei.c:4073 page last free pid 5487 tgid 5487 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1392 [inline] __free_frozen_pages+0xb80/0xd80 mm/page_alloc.c:2892 __slab_free+0x303/0x3c0 mm/slub.c:4591 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4180 [inline] slab_alloc_node mm/slub.c:4229 [inline] __kmalloc_cache_noprof+0x1be/0x3d0 mm/slub.c:4391 kmalloc_noprof include/linux/slab.h:905 [inline] tomoyo_print_header security/tomoyo/audit.c:156 [inline] tomoyo_init_log+0x183/0x1f70 security/tomoyo/audit.c:255 tomoyo_supervisor+0x340/0x1480 security/tomoyo/common.c:2198 tomoyo_audit_env_log security/tomoyo/environ.c:36 [inline] tomoyo_env_perm+0x149/0x1e0 security/tomoyo/environ.c:63 tomoyo_environ security/tomoyo/domain.c:672 [inline] tomoyo_find_next_domain+0x15cf/0x1aa0 security/tomoyo/domain.c:888 tomoyo_bprm_check_security+0x11c/0x180 security/tomoyo/tomoyo.c:102 security_bprm_check+0x89/0x270 security/security.c:1302 search_binary_handler fs/exec.c:1655 [inline] exec_binprm fs/exec.c:1697 [inline] bprm_execve+0x8ee/0x1450 fs/exec.c:1749 do_execveat_common+0x510/0x6a0 fs/exec.c:1855 do_execve fs/exec.c:1929 [inline] __do_sys_execve fs/exec.c:2005 [inline] __se_sys_execve fs/exec.c:2000 [inline] __x64_sys_execve+0x94/0xb0 fs/exec.c:2000 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 Memory state around the buggy address: ffff8880295c2c00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880295c2c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880295c2d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880295c2d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880295c2e00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================