BTRFS: device fsid c9fe44da-de57-406a-8241-57ec7d4412cf devid 1 transid 8 /dev/loop3 (7:3) scanned by syz.3.241 (6819) ================================================================== BUG: KASAN: slab-use-after-free in close_fs_devices+0x81f/0x870 fs/btrfs/volumes.c:1182 Read of size 4 at addr ffff888059c24d30 by task syz.3.241/6819 CPU: 1 UID: 0 PID: 6819 Comm: syz.3.241 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: 0033:0x7fa4887900ca 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:00007fa4896aee68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fa4896aeef0 RCX: 00007fa4887900ca RDX: 0000200000005100 RSI: 0000200000000040 RDI: 00007fa4896aeeb0 RBP: 0000200000005100 R08: 00007fa4896aeef0 R09: 0000000000800810 R10: 0000000000800810 R11: 0000000000000246 R12: 0000200000000040 R13: 00007fa4896aeeb0 R14: 00000000000050f9 R15: 0000200000000140 Allocated by task 6819: 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 5985: 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 ffff888059c24c00 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 304 bytes inside of freed 512-byte region [ffff888059c24c00, ffff888059c24e00) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x59c24 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 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801a441c80 dead000000000100 dead000000000122 head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000002 ffffea0001670901 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 13, tgid 13 (kworker/u8:1), ts 83302537011, free_ts 83285400720 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] switchdev_deferred_enqueue+0x2d/0x240 net/switchdev/switchdev.c:117 __set_ageing_time+0xc8/0x150 net/bridge/br_stp.c:614 br_init_port net/bridge/br_stp_if.c:43 [inline] br_stp_enable_port+0x13f/0x250 net/bridge/br_stp_if.c:93 br_port_carrier_check+0x301/0x3f0 net/bridge/br_if.c:89 br_device_event+0x5fa/0x910 net/bridge/br.c:96 notifier_call_chain+0x1b6/0x3e0 kernel/notifier.c:85 netif_state_change+0x284/0x3a0 net/core/dev.c:1584 linkwatch_do_dev+0x117/0x170 net/core/link_watch.c:186 __linkwatch_run_queue+0x56a/0x7e0 net/core/link_watch.c:244 page last free pid 5927 tgid 5927 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 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:4180 [inline] slab_alloc_node mm/slub.c:4229 [inline] kmem_cache_alloc_noprof+0x1c1/0x3c0 mm/slub.c:4236 dst_alloc+0x105/0x170 net/core/dst.c:89 ip6_dst_alloc net/ipv6/route.c:342 [inline] ip6_rt_pcpu_alloc net/ipv6/route.c:1419 [inline] rt6_make_pcpu_route net/ipv6/route.c:1468 [inline] ip6_pol_route+0xa21/0x1180 net/ipv6/route.c:2305 pol_lookup_func include/net/ip6_fib.h:617 [inline] fib6_rule_lookup+0x52f/0x6f0 net/ipv6/fib6_rules.c:120 ip6_route_input_lookup net/ipv6/route.c:2338 [inline] ip6_route_input+0x6ce/0xa50 net/ipv6/route.c:2641 ip6_rcv_finish+0x141/0x2d0 net/ipv6/ip6_input.c:77 NF_HOOK+0x309/0x3a0 include/linux/netfilter.h:317 __netif_receive_skb_one_core net/core/dev.c:5975 [inline] __netif_receive_skb+0xd3/0x380 net/core/dev.c:6088 process_backlog+0x60e/0x14f0 net/core/dev.c:6440 __napi_poll+0xc7/0x480 net/core/dev.c:7453 napi_poll net/core/dev.c:7517 [inline] net_rx_action+0x707/0xe30 net/core/dev.c:7644 handle_softirqs+0x286/0x870 kernel/softirq.c:579 Memory state around the buggy address: ffff888059c24c00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888059c24c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888059c24d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888059c24d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888059c24e00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================