bcachefs (loop8): set_node_max(): u64s 11 type btree_ptr_v2 0:82:0 len 0 ver 0: seq 4dc858ad08044b41 written 16 min_key POS_MIN durability: 1 ptr: 0:141:0 gen 0 -> SPOS_MAX
 done
bcachefs (loop8): accounting_read... done
bcachefs (loop8): alloc_read... done
bcachefs (loop8): snapshots_read... done
bcachefs (loop8): 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 ffff88802ec67814 by task syz.8.856/10297

CPU: 1 UID: 0 PID: 10297 Comm: syz.8.856 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: 0033:0x7fdb3019038a
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:00007fdb30ffee68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fdb30ffeef0 RCX: 00007fdb3019038a
RDX: 0000200000024c80 RSI: 0000200000000080 RDI: 00007fdb30ffeeb0
RBP: 0000200000024c80 R08: 00007fdb30ffeef0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000000080
R13: 00007fdb30ffeeb0 R14: 0000000000024c6e R15: 0000200000000d40
 </TASK>

Allocated by task 10297:
 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 10297:
 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 ffff88802ec67800
 which belongs to the cache kmalloc-64 of size 64
The buggy address is located 20 bytes inside of
 freed 64-byte region [ffff88802ec67800, ffff88802ec67840)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88802ec67b00 pfn:0x2ec67
flags: 0xfff00000000200(workingset|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000200 ffff88801a8418c0 ffffea0001d5e950 ffffea00015df050
raw: ffff88802ec67b00 000000000020001e 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 13, tgid 13 (kworker/u8:1), ts 12106372966, free_ts 11781710599
 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]
 __do_kmalloc_node mm/slub.c:4364 [inline]
 __kmalloc_noprof+0x2f1/0x4b0 mm/slub.c:4377
 kmalloc_noprof include/linux/slab.h:913 [inline]
 kzalloc_noprof include/linux/slab.h:1043 [inline]
 lsm_blob_alloc security/security.c:690 [inline]
 lsm_task_alloc security/security.c:777 [inline]
 security_task_alloc+0x4d/0x360 security/security.c:3229
 copy_process+0x1530/0x3c00 kernel/fork.c:2160
 kernel_clone+0x21e/0x840 kernel/fork.c:2608
 user_mode_thread+0xdd/0x140 kernel/fork.c:2686
 call_usermodehelper_exec_work+0x5c/0x230 kernel/umh.c:171
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x47c/0x820 arch/x86/kernel/process.c:148
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
 vfree+0x25a/0x400 mm/vmalloc.c:3434
 tpg_free+0x55/0x430 drivers/media/common/v4l2-tpg/v4l2-tpg-core.c:193
 vivid_dev_release+0xc5/0x120 drivers/media/test-drivers/vivid/vivid-core.c:865
 v4l2_device_release drivers/media/v4l2-core/v4l2-device.c:51 [inline]
 kref_put include/linux/kref.h:65 [inline]
 v4l2_device_put+0x81/0xd0 drivers/media/v4l2-core/v4l2-device.c:56
 vivid_create_instance drivers/media/test-drivers/vivid/vivid-core.c:2070 [inline]
 vivid_probe+0x49a5/0x7180 drivers/media/test-drivers/vivid/vivid-core.c:2095
 platform_probe+0xf6/0x190 drivers/base/platform.c:1405
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x26d/0x9e0 drivers/base/dd.c:659
 __driver_probe_device+0x18c/0x2f0 drivers/base/dd.c:801
 driver_probe_device+0x4f/0x430 drivers/base/dd.c:831
 __driver_attach+0x452/0x700 drivers/base/dd.c:1217
 bus_for_each_dev+0x233/0x2b0 drivers/base/bus.c:370
 bus_add_driver+0x345/0x640 drivers/base/bus.c:678
 driver_register+0x23a/0x320 drivers/base/driver.c:249
 vivid_init+0x561/0x5f0 drivers/media/test-drivers/vivid/vivid-core.c:2294
 do_one_initcall+0x233/0x820 init/main.c:1281

Memory state around the buggy address:
 ffff88802ec67700: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc
 ffff88802ec67780: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
>ffff88802ec67800: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
                         ^
 ffff88802ec67880: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff88802ec67900: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
==================================================================