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BUG: KASAN: out-of-bounds in ext4_ext_split fs/ext4/extents.c:1154 [inline]
BUG: KASAN: out-of-bounds in ext4_ext_create_new_leaf fs/ext4/extents.c:1414 [inline]
BUG: KASAN: out-of-bounds in ext4_ext_insert_extent+0x204f/0x4530 fs/ext4/extents.c:2098
Read of size 18446744068927242256 at addr ffff88811d0c3ffc by task syz-executor.2/10794

CPU: 1 PID: 10794 Comm: syz-executor.2 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Call Trace:
 __dump_stack+0x21/0x24 lib/dump_stack.c:77
 dump_stack_lvl+0x169/0x1d8 lib/dump_stack.c:118
 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:435 [inline]
 kasan_report+0xe2/0x130 mm/kasan/report.c:452
 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_split fs/ext4/extents.c:1154 [inline]
 ext4_ext_create_new_leaf fs/ext4/extents.c:1414 [inline]
 ext4_ext_insert_extent+0x204f/0x4530 fs/ext4/extents.c:2098
 ext4_ext_map_blocks+0x148f/0x5d40 fs/ext4/extents.c:4356
 ext4_map_blocks+0x978/0x1bc0 fs/ext4/inode.c:674
 _ext4_get_block+0x1bb/0x4b0 fs/ext4/inode.c:817
 ext4_get_block_unwritten+0x2a/0x40 fs/ext4/inode.c:848
 ext4_block_write_begin+0x567/0x1330 fs/ext4/inode.c:1101
 ext4_write_begin+0x651/0x15a0 fs/ext4/ext4_jbd2.h:-1
 ext4_da_write_begin+0x455/0xe80 fs/ext4/inode.c:3033
 generic_perform_write+0x2be/0x510 mm/filemap.c:3509
 ext4_buffered_write_iter+0x4b8/0x640 fs/ext4/file.c:271
 ext4_file_write_iter+0x536/0x1980 fs/ext4/file.c:-1
 call_write_iter include/linux/fs.h:2066 [inline]
 new_sync_write fs/read_write.c:518 [inline]
 vfs_write+0x725/0xd60 fs/read_write.c:605
 ksys_write+0x140/0x240 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+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7fbbaec338d9
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:00007fbbae7b60c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fbbaed52f80 RCX: 00007fbbaec338d9
RDX: 000000000208e24b RSI: 0000000020000000 RDI: 0000000000000006
RBP: 00007fbbaec8fad0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007fbbaed52f80 R15: 00007ffff3294e58

The buggy address belongs to the page:
page:ffffea00047430c0 refcount:2 mapcount:0 mapping:ffff888109197e10 index:0x80 pfn:0x11d0c3
aops:def_blk_aops ino:0
flags: 0x4000000000022036(referenced|uptodate|lru|active|private|mappedtodisk)
raw: 4000000000022036 ffffea000458c0c8 ffffea0004812308 ffff888109197e10
raw: 0000000000000080 ffff88812704bdc8 00000002ffffffff ffff888100138000
page dumped because: kasan: bad access detected
page->mem_cgroup:ffff888100138000
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x112cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY), pid 408, ts 265833776164, free_ts 265830163354
 set_page_owner include/linux/page_owner.h:35 [inline]
 post_alloc_hook mm/page_alloc.c:2456 [inline]
 prep_new_page+0x179/0x180 mm/page_alloc.c:2462
 get_page_from_freelist+0x2235/0x23d0 mm/page_alloc.c:4254
 __alloc_pages_nodemask+0x268/0x5f0 mm/page_alloc.c:5370
 __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]
 page_cache_ra_unbounded+0x2c8/0x7d0 mm/readahead.c:226
 do_page_cache_ra mm/readahead.c:277 [inline]
 force_page_cache_ra+0x3a9/0x400 mm/readahead.c:308
 page_cache_sync_ra+0x237/0x2a0 mm/readahead.c:582
 page_cache_sync_readahead include/linux/pagemap.h:837 [inline]
 generic_file_buffered_read+0x55b/0x2730 mm/filemap.c:2250
 generic_file_read_iter+0x116/0x560 mm/filemap.c:2568
 blkdev_read_iter+0x12f/0x160 fs/block_dev.c:1956
 call_read_iter include/linux/fs.h:2060 [inline]
 new_sync_read fs/read_write.c:415 [inline]
 vfs_read+0x874/0xa10 fs/read_write.c:496
 ksys_read+0x140/0x240 fs/read_write.c:634
 __do_sys_read fs/read_write.c:644 [inline]
 __se_sys_read fs/read_write.c:642 [inline]
 __x64_sys_read+0x7b/0x90 fs/read_write.c:642
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:28 [inline]
 free_pages_prepare mm/page_alloc.c:1349 [inline]
 free_pcp_prepare mm/page_alloc.c:1421 [inline]
 free_unref_page_prepare+0x2b7/0x2d0 mm/page_alloc.c:3336
 free_unref_page_list+0x12e/0x9b0 mm/page_alloc.c:3443
 release_pages+0xe38/0xe80 mm/swap.c:1103
 __pagevec_release+0x71/0xe0 mm/swap.c:1123
 pagevec_release include/linux/pagevec.h:88 [inline]
 __invalidate_mapping_pages+0x887/0x920 mm/truncate.c:607
 invalidate_mapping_pages+0x27/0x30 mm/truncate.c:632
 invalidate_bdev+0xa3/0x140 fs/block_dev.c:97
 ext4_put_super+0x669/0x9c0 fs/ext4/super.c:1237
 generic_shutdown_super+0x149/0x320 fs/super.c:465
 kill_block_super+0x7f/0xf0 fs/super.c:1469
 deactivate_locked_super+0xa0/0x100 fs/super.c:335
 deactivate_super+0xaf/0xe0 fs/super.c:366
 cleanup_mnt+0x446/0x500 fs/namespace.c:1114
 __cleanup_mnt+0x19/0x20 fs/namespace.c:1121
 task_work_run+0x127/0x190 kernel/task_work.c:189
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_user_mode_loop+0xcb/0xe0 kernel/entry/common.c:172

Memory state around the buggy address:
 ffff88811d0c3e80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88811d0c3f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88811d0c3f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
                                                                ^
 ffff88811d0c4000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88811d0c4080: fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc
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