EXT4-fs error (device loop7): ext4_free_blocks:5685: comm syz.7.35: Freeing blocks not in datazone - block = 262832168119327, count = 5204
==================================================================
BUG: KASAN: use-after-free in ext4_ext_store_pblock fs/ext4/ext4_extents.h:256 [inline]
BUG: KASAN: use-after-free in ext4_ext_rm_leaf fs/ext4/extents.c:2690 [inline]
BUG: KASAN: use-after-free in ext4_ext_remove_space+0x2d9f/0x4e10 fs/ext4/extents.c:2932
Write of size 8 at addr ffff88812fd65878 by task syz.7.35/624

CPU: 1 PID: 624 Comm: syz.7.35 Not tainted 5.10.234-syzkaller-1006808-ge0b88ee5f09c #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
 __asan_report_store_n_noabort+0x12/0x20 mm/kasan/report_generic.c:325
 ext4_ext_store_pblock fs/ext4/ext4_extents.h:256 [inline]
 ext4_ext_rm_leaf fs/ext4/extents.c:2690 [inline]
 ext4_ext_remove_space+0x2d9f/0x4e10 fs/ext4/extents.c:2932
 ext4_ext_truncate+0x17f/0x200 fs/ext4/extents.c:4465
 ext4_truncate+0xb19/0x1220 fs/ext4/inode.c:4366
 ext4_truncate_failed_write fs/ext4/truncate.h:20 [inline]
 ext4_write_begin+0xce0/0x1730 fs/ext4/inode.c:1275
 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: 0033:0x7f5d2c2b9169
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:00007f5d2bd0a038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f5d2c4d2080 RCX: 00007f5d2c2b9169
RDX: 0000000000040010 RSI: 0000400000000180 RDI: 0000000000000006
RBP: 00007f5d2c33a2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f5d2c4d2080 R15: 00007ffdbcfe6068

The buggy address belongs to the page:
page:ffffea0004bf5940 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x12fd65
flags: 0x4000000000000000()
raw: 4000000000000000 dead000000000100 dead000000000122 0000000000000000
raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 0, migratetype Movable, gfp_mask 0x8100dca(GFP_HIGHUSER_MOVABLE|__GFP_ZERO|0x8000000), pid 601, ts 58748277830, free_ts 59001914364
 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]
 do_anonymous_page mm/memory.c:3963 [inline]
 handle_pte_fault+0x175a/0x3e10 mm/memory.c:4786
 __handle_mm_fault mm/memory.c:4944 [inline]
 handle_mm_fault+0x11d6/0x1a10 mm/memory.c:5358
 do_user_addr_fault arch/x86/mm/fault.c:1362 [inline]
 handle_page_fault arch/x86/mm/fault.c:1428 [inline]
 exc_page_fault+0x2a6/0x5b0 arch/x86/mm/fault.c:1484
 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:571
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+0x2ae/0x2d0 mm/page_alloc.c:3336
 free_unref_page_list+0x122/0xb20 mm/page_alloc.c:3443
 release_pages+0xea0/0xef0 mm/swap.c:1103
 free_pages_and_swap_cache+0x8a/0xa0 mm/swap_state.c:356
 tlb_batch_pages_flush mm/mmu_gather.c:49 [inline]
 tlb_flush_mmu_free mm/mmu_gather.c:240 [inline]
 tlb_flush_mmu mm/mmu_gather.c:247 [inline]
 tlb_finish_mmu+0x177/0x320 mm/mmu_gather.c:326
 exit_mmap+0x306/0x560 mm/mmap.c:3375
 __mmput+0x95/0x2d0 kernel/fork.c:1153
 mmput+0x59/0x170 kernel/fork.c:1176
 exit_mm kernel/exit.c:539 [inline]
 do_exit+0xbda/0x2a50 kernel/exit.c:850
 do_group_exit+0x141/0x310 kernel/exit.c:985
 get_signal+0x10a0/0x1410 kernel/signal.c:2793
 arch_do_signal_or_restart+0xbd/0x17c0 arch/x86/kernel/signal.c:805
 handle_signal_work kernel/entry/common.c:145 [inline]
 exit_to_user_mode_loop+0x9b/0xd0 kernel/entry/common.c:169
 exit_to_user_mode_prepare kernel/entry/common.c:199 [inline]
 syscall_exit_to_user_mode+0xa2/0x1a0 kernel/entry/common.c:274
 do_syscall_64+0x40/0x70 arch/x86/entry/common.c:56
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

Memory state around the buggy address:
 ffff88812fd65700: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88812fd65780: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88812fd65800: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                                                ^
 ffff88812fd65880: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88812fd65900: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
EXT4-fs error (device loop7): ext4_free_blocks:5685: comm syz.7.35: Freeing blocks not in datazone - block = 251221545461594, count = 14762
EXT4-fs error (device loop7): ext4_free_blocks:5685: comm syz.7.35: Freeing blocks not in datazone - block = 75451425716958, count = 12153
EXT4-fs error (device loop7): ext4_free_blocks:5685: comm syz.7.35: Freeing blocks not in datazone - block = 170480809659008, count = 4234
EXT4-fs error (device loop7): ext4_free_blocks:5685: comm syz.7.35: Freeing blocks not in datazone - block = 262494569559116, count = 21486
EXT4-fs error (device loop7): ext4_free_blocks:5685: comm syz.7.35: Freeing blocks not in datazone - block = 27279607345010, count = 2045
EXT4-fs error (device loop7): ext4_free_blocks:5685: comm syz.7.35: Freeing blocks not in datazone - block = 159535058223606, count = 9482
EXT4-fs error (device loop7): ext4_free_blocks:5685: comm syz.7.35: Freeing blocks not in datazone - block = 237144270383953, count = 14169
EXT4-fs error (device loop7): ext4_free_blocks:5685: comm syz.7.35: Freeing blocks not in datazone - block = 252727803437934, count = 3947