loop5: detected capacity change from 0 to 32768 BTRFS: device fsid e417788f-7a09-42b2-9266-8ddc5d5d35d2 devid 1 transid 8 /dev/loop5 (7:5) scanned by syz.5.6124 (1494) ================================================================== BUG: KASAN: slab-use-after-free in close_fs_devices+0x81f/0x870 fs/btrfs/volumes.c:1182 Read of size 4 at addr ffff8880271f9930 by task syz.5.6124/1494 CPU: 0 UID: 0 PID: 1494 Comm: syz.5.6124 Not tainted 6.16.0-rc3-next-20250626-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+0xbc/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+0x92/0x2b0 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: 0033:0x7f275db900ca 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:00007f275ea21e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f275ea21ef0 RCX: 00007f275db900ca RDX: 00002000000051c0 RSI: 0000200000005200 RDI: 00007f275ea21eb0 RBP: 00002000000051c0 R08: 00007f275ea21ef0 R09: 0000000001204408 R10: 0000000001204408 R11: 0000000000000246 R12: 0000200000005200 R13: 00007f275ea21eb0 R14: 00000000000051ab R15: 00002000000000c0 Allocated by task 1494: 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+0x92/0x2b0 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 28486: 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+0xf9/0x170 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 ffff8880271f9800 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 304 bytes inside of freed 512-byte region [ffff8880271f9800, ffff8880271f9a00) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x271f8 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 dead000000000100 dead000000000122 raw: 0000000000000000 0000000080100010 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801a441c80 dead000000000100 dead000000000122 head: 0000000000000000 0000000080100010 00000000f5000000 0000000000000000 head: 00fff00000000002 ffffea00009c7e01 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 20581, tgid 20580 (syz.4.3471), ts 2022003731924, free_ts 2021305623351 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] __kmalloc_cache_noprof+0x296/0x3d0 mm/slub.c:4391 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] genradix_alloc_node include/linux/generic-radix-tree.h:101 [inline] __genradix_ptr_alloc+0x352/0x4a0 lib/generic-radix-tree.c:69 __genradix_prealloc+0x44/0x90 lib/generic-radix-tree.c:216 sctp_stream_alloc_out net/sctp/stream.c:104 [inline] sctp_stream_init+0x14b/0x440 net/sctp/stream.c:149 sctp_association_init net/sctp/associola.c:232 [inline] sctp_association_new+0x10dd/0x25f0 net/sctp/associola.c:296 sctp_connect_new_asoc+0x2c5/0x690 net/sctp/socket.c:1092 __sctp_connect+0x5ba/0xd50 net/sctp/socket.c:1198 __sctp_setsockopt_connectx net/sctp/socket.c:1337 [inline] sctp_getsockopt_connectx3+0x2c4/0x440 net/sctp/socket.c:1422 sctp_getsockopt+0x98a/0xb60 net/sctp/socket.c:8134 do_sock_getsockopt+0x35d/0x650 net/socket.c:2405 page last free pid 20561 tgid 20558 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 free_pg_vec net/packet/af_packet.c:4407 [inline] packet_set_ring+0x1899/0x2380 net/packet/af_packet.c:4626 packet_release+0x83e/0xce0 net/packet/af_packet.c:3211 __sock_release net/socket.c:649 [inline] sock_close+0xc0/0x240 net/socket.c:1439 __fput+0x449/0xa70 fs/file_table.c:468 task_work_run+0x1d4/0x260 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:114 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff8880271f9800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880271f9880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880271f9900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880271f9980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880271f9a00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================