loop2: detected capacity change from 0 to 32768 BTRFS: device fsid 395ef67a-297e-477c-816d-cd80a5b93e5d devid 1 transid 8 /dev/loop2 (7:2) scanned by syz.2.40 (6068) ================================================================== BUG: KASAN: slab-use-after-free in close_fs_devices+0x81f/0x870 fs/btrfs/volumes.c:1181 Read of size 4 at addr ffff88806aace530 by task syz.2.40/6068 CPU: 0 UID: 0 PID: 6068 Comm: syz.2.40 Not tainted 6.16.0-rc2-next-20250620-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:1181 btrfs_close_devices+0xc5/0x500 fs/btrfs/volumes.c:1200 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:2059 [inline] btrfs_get_tree+0xa61/0x12d0 fs/btrfs/super.c:2093 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: 0033:0x7f7ebb7900ca 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:00007f7ebc5c5e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f7ebc5c5ef0 RCX: 00007f7ebb7900ca RDX: 0000200000000000 RSI: 00002000000015c0 RDI: 00007f7ebc5c5eb0 RBP: 0000200000000000 R08: 00007f7ebc5c5ef0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00002000000015c0 R13: 00007f7ebc5c5eb0 R14: 000000000000559e R15: 0000200000000040 Allocated by task 6068: 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:4395 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:812 btrfs_scan_one_device+0x3fe/0x5b0 fs/btrfs/volumes.c:1486 btrfs_get_tree_super fs/btrfs/super.c:1857 [inline] btrfs_get_tree_subvol fs/btrfs/super.c:2059 [inline] btrfs_get_tree+0x441/0x12d0 fs/btrfs/super.c:2093 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 5986: 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:2416 [inline] slab_free mm/slub.c:4679 [inline] kfree+0x18e/0x440 mm/slub.c:4878 btrfs_free_stale_devices+0x561/0x5e0 fs/btrfs/volumes.c:563 btrfs_scan_one_device+0x3d6/0x5b0 fs/btrfs/volumes.c:1480 btrfs_control_ioctl+0x128/0x370 fs/btrfs/super.c:2242 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 ffff88806aace400 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 304 bytes inside of freed 512-byte region [ffff88806aace400, ffff88806aace600) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x6aacc head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 ksm flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801a441c80 ffffea00015bcf00 0000000000000003 raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801a441c80 ffffea00015bcf00 0000000000000003 head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000002 ffffea0001aab301 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 0x52820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 5837, tgid 5837 (syz-executor), ts 95108730693, free_ts 95091988002 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1704 prep_new_page mm/page_alloc.c:1712 [inline] get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3669 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4959 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2419 alloc_slab_page mm/slub.c:2486 [inline] allocate_slab+0x8a/0x370 mm/slub.c:2654 new_slab mm/slub.c:2708 [inline] ___slab_alloc+0xbeb/0x1410 mm/slub.c:3890 __slab_alloc mm/slub.c:3980 [inline] __slab_alloc_node mm/slub.c:4055 [inline] slab_alloc_node mm/slub.c:4216 [inline] __do_kmalloc_node mm/slub.c:4363 [inline] __kmalloc_noprof+0x305/0x4f0 mm/slub.c:4376 kmalloc_noprof include/linux/slab.h:909 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] fib6_info_alloc+0x30/0xf0 net/ipv6/ip6_fib.c:155 ip6_route_info_create+0x142/0x860 net/ipv6/route.c:3812 ip6_route_add+0x49/0x1b0 net/ipv6/route.c:3941 addrconf_prefix_route net/ipv6/addrconf.c:2487 [inline] fixup_permanent_addr net/ipv6/addrconf.c:3602 [inline] addrconf_permanent_addr+0x67f/0x9d0 net/ipv6/addrconf.c:3626 addrconf_notify+0x887/0x1010 net/ipv6/addrconf.c:3698 notifier_call_chain+0x1b3/0x3e0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2268 [inline] call_netdevice_notifiers net/core/dev.c:2282 [inline] __dev_notify_flags+0x18d/0x2e0 net/core/dev.c:-1 netif_change_flags+0xe8/0x1a0 net/core/dev.c:9565 do_setlink+0xc55/0x41c0 net/core/rtnetlink.c:3141 page last free pid 5828 tgid 5828 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1248 [inline] __free_frozen_pages+0xc71/0xe70 mm/page_alloc.c:2706 stack_depot_save_flags+0x445/0x900 lib/stackdepot.c:678 kasan_save_stack mm/kasan/common.c:48 [inline] kasan_save_track+0x4f/0x80 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:319 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:345 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4179 [inline] slab_alloc_node mm/slub.c:4228 [inline] kmem_cache_alloc_lru_noprof+0x1c6/0x3d0 mm/slub.c:4247 __d_alloc+0x36/0x7a0 fs/dcache.c:1690 d_alloc_parallel+0xe5/0x15e0 fs/dcache.c:2549 __lookup_slow+0x116/0x3d0 fs/namei.c:1793 start_creating+0x22e/0x3c0 fs/debugfs/inode.c:391 debugfs_create_dir+0x28/0x420 fs/debugfs/inode.c:586 ieee80211_debugfs_add_netdev net/mac80211/debugfs_netdev.c:1005 [inline] ieee80211_debugfs_recreate_netdev+0x1a6/0x1460 net/mac80211/debugfs_netdev.c:1035 ieee80211_if_change_type+0x156/0x990 net/mac80211/iface.c:1982 ieee80211_change_iface+0xd5/0x510 net/mac80211/cfg.c:253 rdev_change_virtual_intf net/wireless/rdev-ops.h:74 [inline] cfg80211_change_iface+0x795/0xef0 net/wireless/util.c:1217 nl80211_set_interface+0x773/0xaa0 net/wireless/nl80211.c:4417 genl_family_rcv_msg_doit+0x212/0x300 net/netlink/genetlink.c:1115 Memory state around the buggy address: ffff88806aace400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88806aace480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88806aace500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88806aace580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88806aace600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================