EXT4-fs error (device loop0): ext4_read_block_bitmap_nowait:476: comm syz-executor.0: Invalid block bitmap block 0 in block_group 0 EXT4-fs (loop0): Remounting filesystem read-only EXT4-fs error (device loop0) in ext4_mb_clear_bb:6178: Corrupt filesystem EXT4-fs (loop0): Remounting filesystem read-only ================================================================== BUG: KASAN: out-of-bounds in ext4_ext_rm_leaf fs/ext4/extents.c:2717 [inline] BUG: KASAN: out-of-bounds in ext4_ext_remove_space+0x1eef/0x4180 fs/ext4/extents.c:2939 Read of size 18446744073709551544 at addr ffff888125a05054 by task syz-executor.0/360 CPU: 0 PID: 360 Comm: syz-executor.0 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Call Trace: __dump_stack+0x21/0x30 lib/dump_stack.c:88 dump_stack_lvl+0xee/0x150 lib/dump_stack.c:106 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:427 [inline] kasan_report+0xf1/0x140 mm/kasan/report.c:444 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x280/0x290 mm/kasan/generic.c:189 memmove+0x2d/0x70 mm/kasan/shadow.c:54 ext4_ext_rm_leaf fs/ext4/extents.c:2717 [inline] ext4_ext_remove_space+0x1eef/0x4180 fs/ext4/extents.c:2939 ext4_punch_hole+0x77c/0xbd0 fs/ext4/inode.c:4137 ext4_fallocate+0x2b6/0x1de0 fs/ext4/extents.c:4765 vfs_fallocate+0x4b4/0x590 fs/open.c:309 ioctl_preallocate fs/ioctl.c:294 [inline] file_ioctl fs/ioctl.c:-1 [inline] do_vfs_ioctl+0x1a96/0x1d00 fs/ioctl.c:853 __do_sys_ioctl fs/ioctl.c:872 [inline] __se_sys_ioctl+0x9f/0x1a0 fs/ioctl.c:860 __x64_sys_ioctl+0x7b/0x90 fs/ioctl.c:860 x64_sys_call+0x2f/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:17 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f7cca956ae9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f7cc20f80c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f7ccaa76050 RCX: 00007f7cca956ae9 RDX: 0000000020000080 RSI: 000000004030582b RDI: 0000000000000004 RBP: 00007f7cca9a247a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f7ccaa76050 R15: 00007fff9cbb1e88 The buggy address belongs to the page: page:ffffea0004968140 refcount:2 mapcount:0 mapping:ffff888109305b18 index:0x3a pfn:0x125a05 memcg:ffff888100251140 aops:def_blk_aops ino:700000 flags: 0x4000000000002036(referenced|uptodate|lru|active|private|zone=1) raw: 4000000000002036 ffffea0004893048 ffff88810025a230 ffff888109305b18 raw: 000000000000003a ffff888122081e70 00000002ffffffff ffff888100251140 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Movable, gfp_mask 0x108c48(GFP_NOFS|__GFP_NOFAIL|__GFP_HARDWALL|__GFP_MOVABLE), pid 357, ts 43713058834, free_ts 0 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x192/0x1b0 mm/page_alloc.c:2605 prep_new_page+0x1c/0x110 mm/page_alloc.c:2611 get_page_from_freelist+0x2cc5/0x2d50 mm/page_alloc.c:4485 __alloc_pages+0x18f/0x440 mm/page_alloc.c:5808 __alloc_pages_node include/linux/gfp.h:595 [inline] alloc_pages_node include/linux/gfp.h:609 [inline] alloc_pages include/linux/gfp.h:622 [inline] __page_cache_alloc include/linux/pagemap.h:305 [inline] pagecache_get_page+0xa82/0xda0 mm/filemap.c:1955 find_or_create_page include/linux/pagemap.h:418 [inline] grow_dev_page fs/buffer.c:949 [inline] grow_buffers fs/buffer.c:1014 [inline] __getblk_slow fs/buffer.c:1041 [inline] __getblk_gfp+0x238/0x7d0 fs/buffer.c:1336 sb_getblk_gfp include/linux/buffer_head.h:368 [inline] ext4_ext_grow_indepth fs/ext4/extents.c:1330 [inline] ext4_ext_create_new_leaf fs/ext4/extents.c:1431 [inline] ext4_ext_insert_extent+0x110f/0x47a0 fs/ext4/extents.c:2103 ext4_ext_map_blocks+0x18e1/0x6270 fs/ext4/extents.c:4362 ext4_map_blocks+0x97b/0x1b20 fs/ext4/inode.c:674 _ext4_get_block+0x1da/0x4e0 fs/ext4/inode.c:817 ext4_get_block+0x39/0x50 fs/ext4/inode.c:834 ext4_block_write_begin+0x556/0x1150 fs/ext4/inode.c:1102 ext4_write_begin+0x638/0x1220 fs/ext4/ext4_jbd2.h:-1 ext4_da_write_begin+0x2fa/0xb60 fs/ext4/inode.c:2988 generic_perform_write+0x2ad/0x670 mm/filemap.c:3870 ext4_buffered_write_iter+0x4ed/0x670 fs/ext4/file.c:270 page_owner free stack trace missing Memory state around the buggy address: ffff888125a04f00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff888125a04f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff888125a05000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ^ ffff888125a05080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888125a05100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ================================================================== EXT4-fs error (device loop0): __ext4_get_inode_loc:4358: comm syz-executor.0: Invalid inode table block 0 in block_group 0 EXT4-fs (loop0): Remounting filesystem read-only EXT4-fs error (device loop0) in ext4_reserve_inode_write:5873: Corrupt filesystem EXT4-fs (loop0): Remounting filesystem read-only EXT4-fs error (device loop0): ext4_punch_hole:4150: inode #16: comm syz-executor.0: mark_inode_dirty error EXT4-fs (loop0): Remounting filesystem read-only