==================================================================
BUG: KASAN: use-after-free in ext4_ext_insert_extent+0x2a72/0x4c30 fs/ext4/extents.c:2152
Read of size 221376 at addr ffff88812f213c3c by task syz.0.16/527

CPU: 0 PID: 527 Comm: syz.0.16 Not tainted 5.10.234-syzkaller-1006684-g094fc3778d6b #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack_lvl+0x1e2/0x24b lib/dump_stack.c:118
 print_address_description+0x81/0x3b0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:435 [inline]
 kasan_report+0x179/0x1c0 mm/kasan/report.c:452
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x293/0x2a0 mm/kasan/generic.c:189
 memmove+0x2d/0x70 mm/kasan/shadow.c:54
 ext4_ext_insert_extent+0x2a72/0x4c30 fs/ext4/extents.c:2152
 ext4_ext_map_blocks+0x1c47/0x6ee0 fs/ext4/extents.c:4354
 ext4_map_blocks+0xa65/0x1d10 fs/ext4/inode.c:673
 _ext4_get_block+0x21b/0x610 fs/ext4/inode.c:816
 ext4_get_block+0x39/0x50 fs/ext4/inode.c:833
 ext4_block_write_begin+0x61e/0x13b0 fs/ext4/inode.c:1100
 ext4_write_begin+0x6fa/0x1730 fs/ext4/ext4_jbd2.h:-1
 ext4_da_write_begin+0x49d/0xf60 fs/ext4/inode.c:3032
 generic_perform_write+0x2cd/0x570 mm/filemap.c:3509
 ext4_buffered_write_iter+0x482/0x610 fs/ext4/file.c:271
 ext4_file_write_iter+0x193/0x1c80 fs/ext4/file.c:685
 call_write_iter include/linux/fs.h:2058 [inline]
 new_sync_write fs/read_write.c:518 [inline]
 vfs_write+0xb4c/0xe70 fs/read_write.c:605
 ksys_write+0x199/0x2c0 fs/read_write.c:658
 __do_sys_write fs/read_write.c:670 [inline]
 __se_sys_write fs/read_write.c:667 [inline]
 __x64_sys_write+0x7b/0x90 fs/read_write.c:667
 do_syscall_64+0x34/0x70 arch/x86/entry/common.c:-1
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7fc7e7d9c169
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fc7e780e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fc7e7fb4fa0 RCX: 00007fc7e7d9c169
RDX: 00000000002a979d RSI: 0000400000000000 RDI: 0000000000000004
RBP: 00007fc7e7e1d2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fc7e7fb4fa0 R15: 00007ffc23c88388

The buggy address belongs to the page:
page:ffffea0004bc84c0 refcount:3 mapcount:0 mapping:ffff8881091a0290 index:0x3f pfn:0x12f213
aops:def_blk_aops ino:0
flags: 0x4000000000002036(referenced|uptodate|lru|active|private)
raw: 4000000000002036 ffffea0004620e88 ffff88812a19e030 ffff8881091a0290
raw: 000000000000003f ffff88812f43d888 00000003ffffffff ffff88810e200000
page dumped because: kasan: bad access detected
page->mem_cgroup:ffff88810e200000
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 527, ts 56767419764, free_ts 0
 set_page_owner include/linux/page_owner.h:35 [inline]
 post_alloc_hook mm/page_alloc.c:2456 [inline]
 prep_new_page+0x166/0x180 mm/page_alloc.c:2462
 get_page_from_freelist+0x2d8c/0x2f30 mm/page_alloc.c:4254
 __alloc_pages_nodemask+0x435/0xaf0 mm/page_alloc.c:5348
 __alloc_pages include/linux/gfp.h:544 [inline]
 __alloc_pages_node include/linux/gfp.h:557 [inline]
 alloc_pages_node include/linux/gfp.h:571 [inline]
 alloc_pages include/linux/gfp.h:590 [inline]
 __page_cache_alloc include/linux/pagemap.h:290 [inline]
 pagecache_get_page+0x669/0x950 mm/filemap.c:1848
 find_or_create_page include/linux/pagemap.h:402 [inline]
 grow_dev_page fs/buffer.c:976 [inline]
 grow_buffers fs/buffer.c:1045 [inline]
 __getblk_slow fs/buffer.c:1072 [inline]
 __getblk_gfp+0x221/0x7e0 fs/buffer.c:1370
 sb_getblk_gfp include/linux/buffer_head.h:368 [inline]
 ext4_ext_grow_indepth fs/ext4/extents.c:1327 [inline]
 ext4_ext_create_new_leaf fs/ext4/extents.c:1426 [inline]
 ext4_ext_insert_extent+0xf33/0x4c30 fs/ext4/extents.c:2097
 ext4_ext_map_blocks+0x1c47/0x6ee0 fs/ext4/extents.c:4354
 ext4_map_blocks+0xa65/0x1d10 fs/ext4/inode.c:673
 _ext4_get_block+0x21b/0x610 fs/ext4/inode.c:816
 ext4_get_block+0x39/0x50 fs/ext4/inode.c:833
 ext4_block_write_begin+0x61e/0x13b0 fs/ext4/inode.c:1100
 ext4_write_begin+0x6fa/0x1730 fs/ext4/ext4_jbd2.h:-1
 ext4_da_write_begin+0x49d/0xf60 fs/ext4/inode.c:3032
 generic_perform_write+0x2cd/0x570 mm/filemap.c:3509
 ext4_buffered_write_iter+0x482/0x610 fs/ext4/file.c:271
 ext4_file_write_iter+0x193/0x1c80 fs/ext4/file.c:685
page_owner free stack trace missing

Memory state around the buggy address:
 ffff88812f222f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88812f222f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88812f223000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff88812f223080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88812f223100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
EXT4-fs error (device loop0): ext4_map_blocks:739: inode #17: block 118173431786692: comm syz.0.16: lblock 99 mapped to illegal pblock 118173431786692 (length 1)
EXT4-fs error (device loop0): ext4_free_blocks:5685: comm syz.0.16: Freeing blocks not in datazone - block = 68637502098394, count = 6326
EXT4-fs error (device loop0): ext4_free_blocks:5685: comm syz.0.16: Freeing blocks not in datazone - block = 212487910165282, count = 9207
EXT4-fs error (device loop0): ext4_free_blocks:5685: comm syz.0.16: Freeing blocks not in datazone - block = 61033412430414, count = 26850
EXT4-fs error (device loop0): ext4_free_blocks:5685: comm syz.0.16: Freeing blocks not in datazone - block = 187397102710564, count = 28571
EXT4-fs error (device loop0): ext4_free_blocks:5685: comm syz.0.16: Freeing blocks not in datazone - block = 91839054560708, count = 29309
EXT4-fs error (device loop0): ext4_free_blocks:5685: comm syz.0.16: Freeing blocks not in datazone - block = 246171080014886, count = 10247
EXT4-fs error (device loop0): ext4_free_blocks:5685: comm syz.0.16: Freeing blocks not in datazone - block = 209471466921957, count = 19767
EXT4-fs error (device loop0): ext4_free_blocks:5685: comm syz.0.16: Freeing blocks not in datazone - block = 23486980925398, count = 8206
EXT4-fs error (device loop0): ext4_free_blocks:5685: comm syz.0.16: Freeing blocks not in datazone - block = 165521888888436, count = 7255