bcachefs (loop1): alloc_read...
 done
bcachefs (loop1): snapshots_read...
 done
bcachefs (loop1): check_allocations...
==================================================================
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 ffff8880767d6594 by task syz.1.155/6866

CPU: 0 UID: 0 PID: 6866 Comm: syz.1.155 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 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 fs/bcachefs/btree_iter.c:2266 [inline]
 bch2_btree_iter_peek_max+0xa56/0x6580 fs/bcachefs/btree_iter.c:2385
 bch2_btree_iter_peek_max_type fs/bcachefs/btree_iter.h:769 [inline]
 bch2_gc_btree fs/bcachefs/btree_gc.c:736 [inline]
 bch2_gc_btrees fs/bcachefs/btree_gc.c:800 [inline]
 bch2_check_allocations+0x149b/0x5870 fs/bcachefs/btree_gc.c:1099
 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: 0033:0x7f358299038a
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:00007f358376ce68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f358376cef0 RCX: 00007f358299038a
RDX: 0000200000024c80 RSI: 0000200000000080 RDI: 00007f358376ceb0
RBP: 0000200000024c80 R08: 00007f358376cef0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000000080
R13: 00007f358376ceb0 R14: 0000000000024c70 R15: 0000200000000440
 </TASK>

Allocated by task 6866:
 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 6866:
 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 ffff8880767d6580
 which belongs to the cache kmalloc-64 of size 64
The buggy address is located 20 bytes inside of
 freed 64-byte region [ffff8880767d6580, ffff8880767d65c0)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x767d6
anon flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000000 ffff88801a8418c0 ffffea0000bc5c40 dead000000000005
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 5868, tgid 5868 (syz-executor), ts 59110679543, free_ts 59104279703
 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]
 __kthread_create_on_node+0xef/0x3e0 kernel/kthread.c:510
 kthread_create_on_node+0xdd/0x130 kernel/kthread.c:587
 napi_kthread_create net/core/dev.c:1636 [inline]
 netif_napi_add_weight_locked+0x6c4/0x970 net/core/dev.c:7373
 netif_napi_add_weight include/linux/netdevice.h:2794 [inline]
 netif_napi_add include/linux/netdevice.h:2811 [inline]
 wg_peer_create+0x54e/0x8a0 drivers/net/wireguard/peer.c:57
 set_peer drivers/net/wireguard/netlink.c:422 [inline]
 wg_set_device+0x10f3/0x1fe0 drivers/net/wireguard/netlink.c:599
 genl_family_rcv_msg_doit+0x215/0x300 net/netlink/genetlink.c:1115
 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
 genl_rcv_msg+0x60e/0x790 net/netlink/genetlink.c:1210
 netlink_rcv_skb+0x205/0x470 net/netlink/af_netlink.c:2552
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
page last free pid 23 tgid 23 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
 rcu_do_batch kernel/rcu/tree.c:2605 [inline]
 rcu_core+0xca8/0x1770 kernel/rcu/tree.c:2861
 handle_softirqs+0x283/0x870 kernel/softirq.c:579
 run_ksoftirqd+0x9b/0x100 kernel/softirq.c:968
 smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160
 kthread+0x711/0x8a0 kernel/kthread.c:463
 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:
 ffff8880767d6480: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
 ffff8880767d6500: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
>ffff8880767d6580: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
                         ^
 ffff8880767d6600: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
 ffff8880767d6680: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc
==================================================================