bcachefs (loop0): alloc_read... done bcachefs (loop0): snapshots_read... done bcachefs (loop0): 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 ffff888033c4d294 by task syz.0.3501/20674 CPU: 0 UID: 0 PID: 20674 Comm: syz.0.3501 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: 0033:0x7f2d6f39038a 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:00007f2d701dee68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f2d701deef0 RCX: 00007f2d6f39038a RDX: 0000200000000000 RSI: 0000200000000080 RDI: 00007f2d701deeb0 RBP: 0000200000000000 R08: 00007f2d701deef0 R09: 0000000000000001 R10: 0000000000000001 R11: 0000000000000246 R12: 0000200000000080 R13: 00007f2d701deeb0 R14: 0000000000024c59 R15: 00002000000000c0 Allocated by task 20674: 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 20674: 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 ffff888033c4d280 which belongs to the cache kmalloc-64 of size 64 The buggy address is located 20 bytes inside of freed 64-byte region [ffff888033c4d280, ffff888033c4d2c0) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x33c4d flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000000 ffff88801a8418c0 dead000000000100 dead000000000122 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 0x52c40(GFP_NOFS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 6267, tgid 6267 (dhcpcd-run-hook), ts 87154765004, free_ts 87141162190 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] tomoyo_encode2 security/tomoyo/realpath.c:45 [inline] tomoyo_encode+0x28b/0x550 security/tomoyo/realpath.c:80 tomoyo_realpath_from_path+0x58d/0x5d0 security/tomoyo/realpath.c:283 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_check_open_permission+0x1c1/0x3b0 security/tomoyo/file.c:771 security_file_open+0xb1/0x270 security/security.c:3183 do_dentry_open+0x384/0x13f0 fs/open.c:942 vfs_open+0x3b/0x340 fs/open.c:1095 do_open fs/namei.c:3887 [inline] path_openat+0x2ee5/0x3830 fs/namei.c:4046 do_filp_open+0x1fa/0x410 fs/namei.c:4073 do_sys_openat2+0x121/0x1c0 fs/open.c:1435 page last free pid 15 tgid 15 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 pagetable_free include/linux/mm.h:2954 [inline] pagetable_dtor_free include/linux/mm.h:3052 [inline] __tlb_remove_table+0x2d2/0x3b0 include/asm-generic/tlb.h:220 __tlb_remove_table_free mm/mmu_gather.c:227 [inline] tlb_remove_table_rcu+0x85/0x100 mm/mmu_gather.c:290 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: ffff888033c4d180: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff888033c4d200: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc >ffff888033c4d280: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ^ ffff888033c4d300: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff888033c4d380: 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc ==================================================================