================================================================== BUG: KASAN: use-after-free in ext4_data_block_valid+0x290/0x2e0 fs/ext4/block_validity.c:210 Read of size 8 at addr ffff8801cd948bb0 by task syz-executor4/3880 CPU: 1 PID: 3880 Comm: syz-executor4 Not tainted 4.9.113-g47bbcd6 #10 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ffff8801a141f520 ffffffff81eb32a9 ffffea0007365200 ffff8801cd948bb0 0000000000000000 ffff8801cd948bb0 00000000000026b3 ffff8801a141f558 ffffffff81567bd9 ffff8801cd948bb0 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 EXT4-fs (sda1): re-mounted. Opts: noblock_validity,,errors=continue [] __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433 [] ext4_data_block_valid+0x290/0x2e0 fs/ext4/block_validity.c:210 [] __check_block_validity.constprop.87+0xc1/0x200 fs/ext4/inode.c:378 [] ext4_map_blocks+0xc87/0x16d0 fs/ext4/inode.c:568 [] ext4_getblk+0x2cc/0x450 fs/ext4/inode.c:943 [] ext4_bread+0x91/0x1d0 fs/ext4/inode.c:993 [] __ext4_read_dirblock+0x37/0xa80 fs/ext4/namei.c:99 [] htree_dirblock_to_tree+0xbb/0x5e0 fs/ext4/namei.c:962 [] ext4_htree_fill_tree+0x223/0x9a0 fs/ext4/namei.c:1081 [] ext4_dx_readdir fs/ext4/dir.c:574 [inline] [] ext4_readdir+0x10e8/0x2a00 fs/ext4/dir.c:121 [] iterate_dir+0x1ac/0x600 fs/readdir.c:50 [] SYSC_getdents fs/readdir.c:230 [inline] [] SyS_getdents+0x13c/0x2a0 fs/readdir.c:211 [] do_syscall_64+0x1a6/0x490 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+0x43/0xd0 mm/kasan/kasan.c:505 set_track mm/kasan/kasan.c:517 [inline] kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:609 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+0xbe/0x290 mm/slub.c:2728 add_system_zone+0x284/0x5d0 fs/ext4/block_validity.c:84 ext4_setup_system_zone+0x30a/0x490 fs/ext4/block_validity.c:168 ext4_fill_super+0x6a50/0xb4b0 fs/ext4/super.c:4190 mount_bdev+0x2c7/0x390 fs/super.c:1100 ext4_mount+0x34/0x40 fs/ext4/super.c:5620 mount_fs+0x28c/0x370 fs/super.c:1206 vfs_kern_mount.part.29+0xd1/0x3d0 fs/namespace.c:991 vfs_kern_mount fs/namespace.c:973 [inline] do_new_mount fs/namespace.c:2513 [inline] do_mount+0x3c9/0x2740 fs/namespace.c:2835 SYSC_mount fs/namespace.c:3051 [inline] SyS_mount+0xfe/0x110 fs/namespace.c:3028 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+0x1d8/0x215 init/do_mounts.c:601 kernel_init_freeable+0x50f/0x52d 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 13806: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57 save_stack+0x43/0xd0 mm/kasan/kasan.c:505 set_track mm/kasan/kasan.c:517 [inline] kasan_slab_free+0x72/0xc0 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+0xd02/0x1d40 fs/ext4/super.c:5112 do_remount_sb2+0x351/0x7d0 fs/super.c:825 do_remount fs/namespace.c:2328 [inline] do_mount+0xf93/0x2740 fs/namespace.c:2826 SYSC_mount fs/namespace.c:3051 [inline] SyS_mount+0xfe/0x110 fs/namespace.c:3028 do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282 entry_SYSCALL_64_after_swapgs+0x5d/0xdb The buggy address belongs to the object at ffff8801cd948b98 which belongs to the cache ext4_system_zone of size 40 The buggy address is located 24 bytes inside of 40-byte region [ffff8801cd948b98, ffff8801cd948bc0) The buggy address belongs to the page: page:ffffea0007365200 count:1 mapcount:0 mapping: (null) index:0xffff8801cd948b60 flags: 0x8000000000000080(slab) page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801cd948a80: fb fb fb fb fb fc fc fb fb fb fb fb fc fc fb fb ffff8801cd948b00: fb fb fb fc fc fb fb fb fb fb fc fc fb fb fb fb >ffff8801cd948b80: fb fc fc fb fb fb fb fb fc fc fc fc fc fc fc fc ^ ffff8801cd948c00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8801cd948c80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================