================================================================== BUG: KASAN: use-after-free in ext4_data_block_valid+0x28a/0x2e0 fs/ext4/block_validity.c:210 Read of size 8 at addr ffff8801d3ecabb0 by task syz-executor4/2342 CPU: 1 PID: 2342 Comm: syz-executor4 Not tainted 4.9.125+ #37 ffff8801a67d76d0 ffffffff81af0ae9 ffffea00074fb280 ffff8801d3ecabb0 0000000000000000 ffff8801d3ecabb0 0000000000002634 ffff8801a67d7708 ffffffff814e0e1d ffff8801d3ecabb0 0000000000000008 0000000000000000 Call Trace: [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0xc1/0x128 lib/dump_stack.c:51 [] print_address_description+0x6c/0x234 mm/kasan/report.c:256 [] kasan_report_error mm/kasan/report.c:355 [inline] [] kasan_report.cold.6+0x242/0x2fe mm/kasan/report.c:412 [] __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433 [] ext4_data_block_valid+0x28a/0x2e0 fs/ext4/block_validity.c:210 [] ext4_valid_extent fs/ext4/extents.c:392 [inline] [] ext4_valid_extent_entries fs/ext4/extents.c:422 [inline] [] __ext4_ext_check+0x935/0xfc0 fs/ext4/extents.c:477 [] ext4_ext_remove_space+0x367/0x3ab0 fs/ext4/extents.c:2951 [] ext4_ext_truncate+0x185/0x280 fs/ext4/extents.c:4664 [] ext4_truncate+0xa15/0x12c0 fs/ext4/inode.c:4247 [] ext4_evict_inode+0xd7a/0x1230 fs/ext4/inode.c:265 [] evict+0x22e/0x4f0 fs/inode.c:553 [] iput_final fs/inode.c:1516 [inline] [] iput+0x371/0x900 fs/inode.c:1543 [] dentry_unlink_inode+0x265/0x320 fs/dcache.c:367 [] d_delete+0x1ce/0x290 fs/dcache.c:2392 [] vfs_rmdir2+0x32e/0x410 fs/namei.c:3897 [] do_rmdir+0x304/0x3b0 fs/namei.c:3951 [] SYSC_rmdir fs/namei.c:3969 [inline] [] SyS_rmdir+0x1a/0x20 fs/namei.c:3967 [] do_syscall_64+0x19f/0x480 arch/x86/entry/common.c:282 [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb Allocated by task 1: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57 save_stack mm/kasan/kasan.c:505 [inline] set_track mm/kasan/kasan.c:517 [inline] kasan_kmalloc.part.1+0x62/0xf0 mm/kasan/kasan.c:609 kasan_kmalloc+0xaf/0xc0 mm/kasan/kasan.c:594 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:547 slab_post_alloc_hook mm/slab.h:417 [inline] slab_alloc_node mm/slub.c:2715 [inline] slab_alloc mm/slub.c:2723 [inline] kmem_cache_alloc+0xd5/0x2b0 mm/slub.c:2728 add_system_zone+0x26f/0x500 fs/ext4/block_validity.c:84 ext4_setup_system_zone+0x30a/0x490 fs/ext4/block_validity.c:168 ext4_fill_super+0x716e/0xb700 fs/ext4/super.c:4178 mount_bdev+0x2be/0x380 fs/super.c:1100 ext4_mount+0x34/0x40 fs/ext4/super.c:5608 mount_fs+0x28c/0x370 fs/super.c:1206 vfs_kern_mount.part.8+0xd1/0x3d0 fs/namespace.c:1000 vfs_kern_mount fs/namespace.c:982 [inline] do_new_mount fs/namespace.c:2537 [inline] do_mount+0x3c9/0x2790 fs/namespace.c:2859 SYSC_mount fs/namespace.c:3075 [inline] SyS_mount+0xea/0x100 fs/namespace.c:3052 do_mount_root init/do_mounts.c:366 [inline] mount_block_root+0x35d/0x711 init/do_mounts.c:396 mount_root+0x77/0x7a init/do_mounts.c:541 prepare_namespace+0x1d3/0x210 init/do_mounts.c:601 kernel_init_freeable+0x38e/0x3ac init/main.c:1036 kernel_init+0x11/0x15e init/main.c:946 ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373 Freed by task 32047: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57 save_stack mm/kasan/kasan.c:505 [inline] set_track mm/kasan/kasan.c:517 [inline] kasan_slab_free+0xac/0x190 mm/kasan/kasan.c:582 slab_free_hook mm/slub.c:1355 [inline] slab_free_freelist_hook mm/slub.c:1377 [inline] slab_free mm/slub.c:2958 [inline] kmem_cache_free+0xbe/0x310 mm/slub.c:2980 ext4_release_system_zone+0x7c/0x110 fs/ext4/block_validity.c:186 ext4_setup_system_zone+0x3cd/0x490 fs/ext4/block_validity.c:150 ext4_remount+0xc57/0x1c50 fs/ext4/super.c:5100 do_remount_sb2+0x351/0x7d0 fs/super.c:825 do_remount fs/namespace.c:2352 [inline] do_mount+0xf91/0x2790 fs/namespace.c:2850 SYSC_mount fs/namespace.c:3075 [inline] SyS_mount+0xea/0x100 fs/namespace.c:3052 do_syscall_64+0x19f/0x480 arch/x86/entry/common.c:282 entry_SYSCALL_64_after_swapgs+0x5d/0xdb The buggy address belongs to the object at ffff8801d3ecab98 which belongs to the cache ext4_system_zone of size 40 The buggy address is located 24 bytes inside of 40-byte region [ffff8801d3ecab98, ffff8801d3ecabc0) The buggy address belongs to the page: page:ffffea00074fb280 count:1 mapcount:0 mapping: (null) index:0xffff8801d3ecab60 flags: 0x4000000000000080(slab) page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801d3ecaa80: fb fb fb fb fb fc fc fb fb fb fb fb fc fc fb fb ffff8801d3ecab00: fb fb fb fc fc fb fb fb fb fb fc fc fb fb fb fb >ffff8801d3ecab80: fb fc fc fb fb fb fb fb fc fc fc fc fc fc fc fc ^ ffff8801d3ecac00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8801d3ecac80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================