ext4 filesystem being mounted at /0/file1 supports timestamps until 2038-01-19 (0x7fffffff)
==================================================================
BUG: KASAN: use-after-free in ext4_ext_rm_leaf fs/ext4/extents.c:2601 [inline]
BUG: KASAN: use-after-free in ext4_ext_remove_space+0x3496/0x40d0 fs/ext4/extents.c:2939
Read of size 4 at addr ffff88812ce3c69c by task syz.8.1610/5391

CPU: 0 PID: 5391 Comm: syz.8.1610 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
 <TASK>
 __dump_stack+0x21/0x30 lib/dump_stack.c:88
 dump_stack_lvl+0x110/0x170 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
 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:308
 ext4_ext_rm_leaf fs/ext4/extents.c:2601 [inline]
 ext4_ext_remove_space+0x3496/0x40d0 fs/ext4/extents.c:2939
 ext4_ext_truncate+0x1a3/0x250 fs/ext4/extents.c:4489
 ext4_truncate+0x9be/0xfb0 fs/ext4/inode.c:4294
 ext4_setattr+0x10cc/0x1ac0 fs/ext4/inode.c:5651
 notify_change+0xbca/0xe90 fs/attr.c:505
 do_truncate+0x1ac/0x240 fs/open.c:66
 handle_truncate fs/namei.c:3273 [inline]
 do_open fs/namei.c:3620 [inline]
 path_openat+0x2895/0x2f20 fs/namei.c:3750
 do_filp_open+0x1e2/0x410 fs/namei.c:3777
 do_sys_openat2+0x15e/0x7f0 fs/open.c:1236
 do_sys_open fs/open.c:1252 [inline]
 __do_sys_creat fs/open.c:1328 [inline]
 __se_sys_creat fs/open.c:1322 [inline]
 __x64_sys_creat+0x8e/0xb0 fs/open.c:1322
 x64_sys_call+0x94a/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:86
 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: 0033:0x7fb9511f7e59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fb95105a028 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
RAX: ffffffffffffffda RBX: 00007fb951470fa0 RCX: 00007fb9511f7e59
RDX: 0000000000000000 RSI: 0000000000000100 RDI: 0000200000000100
RBP: 00007fb95128dd6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb951471038 R14: 00007fb951470fa0 R15: 00007ffefbb8eeb8
 </TASK>

The buggy address belongs to the page:
page:ffffea0004b38f00 refcount:0 mapcount:-128 mapping:0000000000000000 index:0x0 pfn:0x12ce3c
flags: 0x4000000000000000(zone=1)
raw: 4000000000000000 ffffea0004b0e508 ffffea000432b848 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffff7f 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x500dc0(GFP_USER|__GFP_ZERO|__GFP_ACCOUNT), pid 4427, ts 489756122975, free_ts 489950626570
 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+0x2d3a/0x2dc0 mm/page_alloc.c:4485
 __alloc_pages+0x1a2/0x460 mm/page_alloc.c:5822
 __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]
 __pte_alloc_one include/asm-generic/pgalloc.h:63 [inline]
 pte_alloc_one+0x70/0x190 arch/x86/mm/pgtable.c:33
 __do_fault+0x201/0x2f0 mm/memory.c:4186
 do_shared_fault mm/memory.c:4618 [inline]
 do_fault mm/memory.c:4701 [inline]
 handle_pte_fault+0xb98/0x2710 mm/memory.c:4911
 __handle_mm_fault mm/memory.c:-1 [inline]
 do_handle_mm_fault+0x1af9/0x1de0 mm/memory.c:5333
 handle_mm_fault include/linux/mm.h:1847 [inline]
 do_user_addr_fault+0x828/0x1250 arch/x86/mm/fault.c:1416
 handle_page_fault arch/x86/mm/fault.c:1507 [inline]
 exc_page_fault+0x51/0xb0 arch/x86/mm/fault.c:1560
 asm_exc_page_fault+0x27/0x30 arch/x86/include/asm/idtentry.h:606
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:26 [inline]
 free_pages_prepare mm/page_alloc.c:1472 [inline]
 free_pcp_prepare mm/page_alloc.c:1544 [inline]
 free_unref_page_prepare+0x542/0x550 mm/page_alloc.c:3534
 free_unref_page_list+0x13a/0x9d0 mm/page_alloc.c:3671
 release_pages+0x1006/0x1060 mm/swap.c:1015
 free_pages_and_swap_cache+0x86/0xa0 mm/swap_state.c:320
 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+0x17e/0x310 mm/mmu_gather.c:338
 exit_mmap+0x43b/0x8b0 mm/mmap.c:3248
 __mmput+0x93/0x320 kernel/fork.c:1180
 mmput+0x50/0x150 kernel/fork.c:1203
 exit_mm kernel/exit.c:554 [inline]
 do_exit+0x9f2/0x27e0 kernel/exit.c:876
 do_group_exit+0x141/0x310 kernel/exit.c:1003
 get_signal+0x66a/0x1480 kernel/signal.c:2907
 arch_do_signal_or_restart+0xdf/0x11c0 arch/x86/kernel/signal.c:867
 handle_signal_work kernel/entry/common.c:154 [inline]
 exit_to_user_mode_loop+0xa7/0xe0 kernel/entry/common.c:178
 exit_to_user_mode_prepare+0x87/0xd0 kernel/entry/common.c:214
 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
 syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:307
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86

Memory state around the buggy address:
 ffff88812ce3c580: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88812ce3c600: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88812ce3c680: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                            ^
 ffff88812ce3c700: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88812ce3c780: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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