io_time[WRITE] 1280 fragmentation 0 bp_start 7 incorrectly set at freespace:0:42:0 (free 0, genbits 0 should be 0), fixing ================================================================== BUG: KASAN: slab-use-after-free in bch2_bucket_alloc_trans+0x1aa0/0x2410 fs/bcachefs/alloc_foreground.c:547 Read of size 8 at addr ffff88805a21dd20 by task syz.0.1/5937 CPU: 1 UID: 0 PID: 5937 Comm: syz.0.1 Not tainted 6.16.0-rc3-syzkaller-00072-gee88bddf7f2f #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 bch2_bucket_alloc_trans+0x1aa0/0x2410 fs/bcachefs/alloc_foreground.c:547 bch2_bucket_alloc_set_trans+0x5a6/0xe70 fs/bcachefs/alloc_foreground.c:728 __open_bucket_add_buckets+0x1437/0x1e40 fs/bcachefs/alloc_foreground.c:925 open_bucket_add_buckets+0x2ee/0x440 fs/bcachefs/alloc_foreground.c:957 bch2_alloc_sectors_start_trans+0xd26/0x1e80 fs/bcachefs/alloc_foreground.c:-1 __bch2_btree_node_alloc fs/bcachefs/btree_update_interior.c:320 [inline] bch2_btree_reserve_get+0x641/0x1810 fs/bcachefs/btree_update_interior.c:534 bch2_btree_update_start+0x147e/0x1dc0 fs/bcachefs/btree_update_interior.c:1270 bch2_btree_split_leaf+0x14b/0x8e0 fs/bcachefs/btree_update_interior.c:1920 bch2_trans_commit_error+0x1b7/0x1130 fs/bcachefs/btree_trans_commit.c:911 __bch2_trans_commit+0x1ce8/0x8880 fs/bcachefs/btree_trans_commit.c:1098 bch2_trans_commit fs/bcachefs/btree_update.h:242 [inline] bch2_journal_replay+0x1789/0x2620 fs/bcachefs/recovery.c:396 bch2_run_recovery_pass fs/bcachefs/recovery_passes.c:485 [inline] __bch2_run_recovery_passes+0x392/0x1010 fs/bcachefs/recovery_passes.c:540 bch2_run_recovery_passes+0x184/0x210 fs/bcachefs/recovery_passes.c:611 bch2_fs_recovery+0x25fd/0x3950 fs/bcachefs/recovery.c:989 bch2_fs_start+0xa99/0xd90 fs/bcachefs/super.c:1203 bch2_fs_get_tree+0xb02/0x14f0 fs/bcachefs/fs.c:2489 vfs_get_tree+0x8f/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: 0033:0x7f39897900ca 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:00007f398a60ee68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f398a60eef0 RCX: 00007f39897900ca RDX: 0000200000000080 RSI: 0000200000000000 RDI: 00007f398a60eeb0 RBP: 0000200000000080 R08: 00007f398a60eef0 R09: 0000000000800000 R10: 0000000000800000 R11: 0000000000000246 R12: 0000200000000000 R13: 00007f398a60eeb0 R14: 0000000000005943 R15: 0000200000000240 Allocated by task 5937: 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] __do_kmalloc_node mm/slub.c:4328 [inline] __kmalloc_node_track_caller_noprof+0x271/0x4e0 mm/slub.c:4347 __do_krealloc mm/slub.c:4905 [inline] krealloc_noprof+0x124/0x340 mm/slub.c:4958 __bch2_trans_kmalloc+0x26c/0xc80 fs/bcachefs/btree_iter.c:3187 bch2_trans_kmalloc_nomemzero_ip fs/bcachefs/btree_iter.h:586 [inline] bch2_trans_kmalloc_nomemzero fs/bcachefs/btree_iter.h:621 [inline] bch2_alloc_sectors_start_trans+0x1d59/0x1e80 fs/bcachefs/alloc_foreground.c:1250 __bch2_btree_node_alloc fs/bcachefs/btree_update_interior.c:320 [inline] bch2_btree_reserve_get+0x641/0x1810 fs/bcachefs/btree_update_interior.c:534 bch2_btree_update_start+0x147e/0x1dc0 fs/bcachefs/btree_update_interior.c:1270 bch2_btree_split_leaf+0x14b/0x8e0 fs/bcachefs/btree_update_interior.c:1920 bch2_trans_commit_error+0x1b7/0x1130 fs/bcachefs/btree_trans_commit.c:911 __bch2_trans_commit+0x1ce8/0x8880 fs/bcachefs/btree_trans_commit.c:1098 bch2_trans_commit fs/bcachefs/btree_update.h:242 [inline] bch2_journal_replay+0x1789/0x2620 fs/bcachefs/recovery.c:396 bch2_run_recovery_pass fs/bcachefs/recovery_passes.c:485 [inline] __bch2_run_recovery_passes+0x392/0x1010 fs/bcachefs/recovery_passes.c:540 bch2_run_recovery_passes+0x184/0x210 fs/bcachefs/recovery_passes.c:611 bch2_fs_recovery+0x25fd/0x3950 fs/bcachefs/recovery.c:989 bch2_fs_start+0xa99/0xd90 fs/bcachefs/super.c:1203 bch2_fs_get_tree+0xb02/0x14f0 fs/bcachefs/fs.c:2489 vfs_get_tree+0x8f/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 5937: 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:2381 [inline] slab_free mm/slub.c:4643 [inline] kfree+0x18e/0x440 mm/slub.c:4842 krealloc_noprof+0x1cd/0x340 mm/slub.c:-1 __bch2_trans_kmalloc+0x26c/0xc80 fs/bcachefs/btree_iter.c:3187 bch2_trans_kmalloc_nomemzero_ip fs/bcachefs/btree_iter.h:586 [inline] bch2_trans_kmalloc_nomemzero fs/bcachefs/btree_iter.h:621 [inline] __bch2_trans_subbuf_alloc+0x2da/0x460 fs/bcachefs/btree_update.c:557 bch2_trans_subbuf_alloc fs/bcachefs/btree_update.h:148 [inline] bch2_trans_jset_entry_alloc fs/bcachefs/btree_update.h:168 [inline] __bch2_trans_log_str fs/bcachefs/btree_update.c:814 [inline] bch2_trans_log_str+0xd5/0x3c0 fs/bcachefs/btree_update.c:827 __bch2_fsck_err+0xc11/0xfb0 fs/bcachefs/error.c:625 bch2_check_discard_freespace_key+0x71b/0xce0 fs/bcachefs/alloc_background.c:1436 try_alloc_bucket fs/bcachefs/alloc_foreground.c:272 [inline] bch2_bucket_alloc_freelist fs/bcachefs/alloc_foreground.c:420 [inline] bch2_bucket_alloc_trans+0x1333/0x2410 fs/bcachefs/alloc_foreground.c:544 bch2_bucket_alloc_set_trans+0x5a6/0xe70 fs/bcachefs/alloc_foreground.c:728 __open_bucket_add_buckets+0x1437/0x1e40 fs/bcachefs/alloc_foreground.c:925 open_bucket_add_buckets+0x2ee/0x440 fs/bcachefs/alloc_foreground.c:957 bch2_alloc_sectors_start_trans+0xd26/0x1e80 fs/bcachefs/alloc_foreground.c:-1 __bch2_btree_node_alloc fs/bcachefs/btree_update_interior.c:320 [inline] bch2_btree_reserve_get+0x641/0x1810 fs/bcachefs/btree_update_interior.c:534 bch2_btree_update_start+0x147e/0x1dc0 fs/bcachefs/btree_update_interior.c:1270 bch2_btree_split_leaf+0x14b/0x8e0 fs/bcachefs/btree_update_interior.c:1920 bch2_trans_commit_error+0x1b7/0x1130 fs/bcachefs/btree_trans_commit.c:911 __bch2_trans_commit+0x1ce8/0x8880 fs/bcachefs/btree_trans_commit.c:1098 bch2_trans_commit fs/bcachefs/btree_update.h:242 [inline] bch2_journal_replay+0x1789/0x2620 fs/bcachefs/recovery.c:396 bch2_run_recovery_pass fs/bcachefs/recovery_passes.c:485 [inline] __bch2_run_recovery_passes+0x392/0x1010 fs/bcachefs/recovery_passes.c:540 bch2_run_recovery_passes+0x184/0x210 fs/bcachefs/recovery_passes.c:611 bch2_fs_recovery+0x25fd/0x3950 fs/bcachefs/recovery.c:989 bch2_fs_start+0xa99/0xd90 fs/bcachefs/super.c:1203 bch2_fs_get_tree+0xb02/0x14f0 fs/bcachefs/fs.c:2489 vfs_get_tree+0x8f/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 The buggy address belongs to the object at ffff88805a21dc00 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 288 bytes inside of freed 512-byte region [ffff88805a21dc00, ffff88805a21de00) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5a21c 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 dead000000000122 0000000000000000 raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801a441c80 dead000000000122 0000000000000000 head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000002 ffffea0001688701 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5192, tgid 5192 (udevd), ts 95502218561, free_ts 28070389758 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1704 prep_new_page mm/page_alloc.c:1712 [inline] get_page_from_freelist+0x21d5/0x22b0 mm/page_alloc.c:3669 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4959 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2419 alloc_slab_page mm/slub.c:2451 [inline] allocate_slab+0x8a/0x3b0 mm/slub.c:2619 new_slab mm/slub.c:2673 [inline] ___slab_alloc+0xbfc/0x1480 mm/slub.c:3859 __slab_alloc mm/slub.c:3949 [inline] __slab_alloc_node mm/slub.c:4024 [inline] slab_alloc_node mm/slub.c:4185 [inline] __kmalloc_cache_noprof+0x296/0x3d0 mm/slub.c:4354 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] kernfs_fop_open+0x397/0xca0 fs/kernfs/file.c:623 do_dentry_open+0xdf3/0x1970 fs/open.c:964 vfs_open+0x3b/0x340 fs/open.c:1094 do_open fs/namei.c:3896 [inline] path_openat+0x2ee5/0x3830 fs/namei.c:4055 do_filp_open+0x1fa/0x410 fs/namei.c:4082 do_sys_openat2+0x121/0x1c0 fs/open.c:1437 do_sys_open fs/open.c:1452 [inline] __do_sys_openat fs/open.c:1468 [inline] __se_sys_openat fs/open.c:1463 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1463 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 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:1248 [inline] __free_frozen_pages+0xc65/0xe60 mm/page_alloc.c:2706 __free_pages mm/page_alloc.c:5071 [inline] free_contig_range+0x1bd/0x4a0 mm/page_alloc.c:6927 destroy_args+0x7e/0x5d0 mm/debug_vm_pgtable.c:1009 debug_vm_pgtable+0x412/0x450 mm/debug_vm_pgtable.c:1389 do_one_initcall+0x233/0x820 init/main.c:1274 do_initcall_level+0x137/0x1f0 init/main.c:1336 do_initcalls+0x69/0xd0 init/main.c:1352 kernel_init_freeable+0x3d9/0x570 init/main.c:1584 kernel_init+0x1d/0x1d0 init/main.c:1474 ret_from_fork+0x3fc/0x770 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: ffff88805a21dc00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805a21dc80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88805a21dd00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88805a21dd80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805a21de00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================