bcachefs (loop5): snapshots_read... done bcachefs (loop5): check_alloc_info... ================================================================== BUG: KASAN: slab-use-after-free in __journal_key_cmp fs/bcachefs/btree_journal_iter.h:63 [inline] BUG: KASAN: slab-use-after-free in __bch2_journal_key_search+0x57b/0x12e0 fs/bcachefs/btree_journal_iter.c:54 Read of size 4 at addr ffff888058be3414 by task syz.5.851/9281 CPU: 0 UID: 0 PID: 9281 Comm: syz.5.851 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x240 mm/kasan/report.c:482 kasan_report+0x118/0x150 mm/kasan/report.c:595 __journal_key_cmp fs/bcachefs/btree_journal_iter.h:63 [inline] __bch2_journal_key_search+0x57b/0x12e0 fs/bcachefs/btree_journal_iter.c:54 bch2_journal_key_search fs/bcachefs/btree_journal_iter.c:73 [inline] bch2_journal_iter_init fs/bcachefs/btree_journal_iter.c:540 [inline] __bch2_btree_and_journal_iter_init_node_iter+0x3ad/0x9f0 fs/bcachefs/btree_journal_iter.c:659 btree_node_iter_and_journal_peek+0x210/0x10a0 fs/bcachefs/btree_iter.c:899 btree_path_down fs/bcachefs/btree_iter.c:956 [inline] bch2_btree_path_traverse_one+0x148d/0x21d0 fs/bcachefs/btree_iter.c:1199 bch2_btree_path_traverse fs/bcachefs/btree_iter.h:252 [inline] bch2_btree_iter_peek_slot+0x7d6/0x2730 fs/bcachefs/btree_iter.c:2845 bch2_get_key_or_hole+0xd6/0xa90 fs/bcachefs/alloc_background.c:1040 bch2_get_key_or_real_bucket_hole fs/bcachefs/alloc_background.c:1111 [inline] bch2_check_alloc_info+0x77e/0x2d40 fs/bcachefs/alloc_background.c:1564 bch2_run_recovery_pass fs/bcachefs/recovery_passes.c:487 [inline] __bch2_run_recovery_passes+0x3b7/0x1090 fs/bcachefs/recovery_passes.c:543 bch2_run_recovery_passes+0x184/0x210 fs/bcachefs/recovery_passes.c:614 bch2_fs_recovery+0x1af4/0x2c20 fs/bcachefs/recovery.c:813 bch2_fs_start+0x97f/0xd10 fs/bcachefs/super.c:1405 bch2_fs_get_tree+0xb35/0x1540 fs/bcachefs/fs.c:2446 vfs_get_tree+0x92/0x2b0 fs/super.c:1752 do_new_mount+0x2a2/0xa30 fs/namespace.c:3810 do_mount fs/namespace.c:4138 [inline] __do_sys_mount fs/namespace.c:4349 [inline] __se_sys_mount+0x317/0x410 fs/namespace.c:4326 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc723f9038a 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:00007fc724e8ce68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fc724e8cef0 RCX: 00007fc723f9038a RDX: 0000200000000000 RSI: 0000200000000080 RDI: 00007fc724e8ceb0 RBP: 0000200000000000 R08: 00007fc724e8cef0 R09: 0000000000000001 R10: 0000000000000001 R11: 0000000000000246 R12: 0000200000000080 R13: 00007fc724e8ceb0 R14: 0000000000024c59 R15: 00002000000000c0 Allocated by task 9281: kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 poison_kmalloc_redzone mm/kasan/common.c:397 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:414 kasan_kmalloc include/linux/kasan.h:260 [inline] __kmalloc_cache_noprof+0x21c/0x3a0 mm/slub.c:4396 kmalloc_noprof include/linux/slab.h:909 [inline] bch2_journal_key_insert fs/bcachefs/btree_journal_iter.c:360 [inline] bch2_journal_key_delete+0xff/0x230 fs/bcachefs/btree_journal_iter.c:379 bch2_btree_repair_topology_recurse+0xeb2/0x5070 fs/bcachefs/btree_gc.c:379 bch2_check_topology+0x1059/0x19f0 fs/bcachefs/btree_gc.c:614 bch2_run_recovery_pass fs/bcachefs/recovery_passes.c:487 [inline] __bch2_run_recovery_passes+0x3b7/0x1090 fs/bcachefs/recovery_passes.c:543 bch2_run_recovery_passes+0x184/0x210 fs/bcachefs/recovery_passes.c:614 bch2_fs_recovery+0x1af4/0x2c20 fs/bcachefs/recovery.c:813 bch2_fs_start+0x97f/0xd10 fs/bcachefs/super.c:1405 bch2_fs_get_tree+0xb35/0x1540 fs/bcachefs/fs.c:2446 vfs_get_tree+0x92/0x2b0 fs/super.c:1752 do_new_mount+0x2a2/0xa30 fs/namespace.c:3810 do_mount fs/namespace.c:4138 [inline] __do_sys_mount fs/namespace.c:4349 [inline] __se_sys_mount+0x317/0x410 fs/namespace.c:4326 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 9281: kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 __kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:587 kasan_save_free_info mm/kasan/kasan.h:406 [inline] poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5b/0x80 mm/kasan/common.c:284 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 bch2_journal_key_insert_take+0x160e/0x1af0 fs/bcachefs/btree_journal_iter.c:300 set_node_max+0x3f7/0x680 fs/bcachefs/btree_gc.c:172 btree_repair_node_end fs/bcachefs/btree_gc.c:329 [inline] bch2_btree_repair_topology_recurse+0x3942/0x5070 fs/bcachefs/btree_gc.c:447 bch2_check_topology+0x1059/0x19f0 fs/bcachefs/btree_gc.c:614 bch2_run_recovery_pass fs/bcachefs/recovery_passes.c:487 [inline] __bch2_run_recovery_passes+0x3b7/0x1090 fs/bcachefs/recovery_passes.c:543 bch2_run_recovery_passes+0x184/0x210 fs/bcachefs/recovery_passes.c:614 bch2_fs_recovery+0x1af4/0x2c20 fs/bcachefs/recovery.c:813 bch2_fs_start+0x97f/0xd10 fs/bcachefs/super.c:1405 bch2_fs_get_tree+0xb35/0x1540 fs/bcachefs/fs.c:2446 vfs_get_tree+0x92/0x2b0 fs/super.c:1752 do_new_mount+0x2a2/0xa30 fs/namespace.c:3810 do_mount fs/namespace.c:4138 [inline] __do_sys_mount fs/namespace.c:4349 [inline] __se_sys_mount+0x317/0x410 fs/namespace.c:4326 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888058be3400 which belongs to the cache kmalloc-64 of size 64 The buggy address is located 20 bytes inside of freed 64-byte region [ffff888058be3400, ffff888058be3440) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x58be3 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000000 ffff88801a8418c0 ffffea0001668480 dead000000000002 raw: 0000000000000000 0000000000200020 00000000f5000000 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x52cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 5867, tgid 5867 (syz-executor), ts 67031654313, free_ts 22174736458 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1851 prep_new_page mm/page_alloc.c:1859 [inline] get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3858 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5148 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416 alloc_slab_page mm/slub.c:2487 [inline] allocate_slab+0x8a/0x330 mm/slub.c:2655 new_slab mm/slub.c:2709 [inline] ___slab_alloc+0xbd1/0x13e0 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+0x282/0x3a0 mm/slub.c:4391 kmalloc_noprof include/linux/slab.h:909 [inline] kzalloc_noprof include/linux/slab.h:1043 [inline] mpls_add_dev net/mpls/af_mpls.c:1443 [inline] mpls_dev_notify+0x121/0x7a0 net/mpls/af_mpls.c:1600 notifier_call_chain+0x1b3/0x3e0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2267 [inline] call_netdevice_notifiers net/core/dev.c:2281 [inline] register_netdevice+0x1608/0x1ae0 net/core/dev.c:11244 veth_newlink+0x5cc/0xa50 drivers/net/veth.c:1884 rtnl_newlink_create+0x30d/0xb00 net/core/rtnetlink.c:3825 __rtnl_newlink net/core/rtnetlink.c:3942 [inline] rtnl_newlink+0x16d6/0x1c70 net/core/rtnetlink.c:4057 rtnetlink_rcv_msg+0x7cc/0xb70 net/core/rtnetlink.c:6946 netlink_rcv_skb+0x205/0x470 net/netlink/af_netlink.c:2552 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1346 page last free pid 1 tgid 1 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1395 [inline] __free_frozen_pages+0xbc4/0xd30 mm/page_alloc.c:2895 __free_pages mm/page_alloc.c:5260 [inline] free_contig_range+0x1bd/0x4a0 mm/page_alloc.c:7087 destroy_args+0x69/0x660 mm/debug_vm_pgtable.c:958 debug_vm_pgtable+0x39f/0x3b0 mm/debug_vm_pgtable.c:1345 do_one_initcall+0x233/0x820 init/main.c:1281 do_initcall_level+0x104/0x190 init/main.c:1343 do_initcalls+0x59/0xa0 init/main.c:1359 kernel_init_freeable+0x334/0x4b0 init/main.c:1591 kernel_init+0x1d/0x1d0 init/main.c:1481 ret_from_fork+0x47c/0x820 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Memory state around the buggy address: ffff888058be3300: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff888058be3380: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc >ffff888058be3400: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ^ ffff888058be3480: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc ffff888058be3500: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc ==================================================================