================================================================== 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 ffff88812e89fdb8 by task syz-executor/362 CPU: 1 PID: 362 Comm: syz-executor Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: __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:4473 ext4_truncate+0x9be/0xfb0 fs/ext4/inode.c:4287 ext4_evict_inode+0xcc5/0x1460 fs/ext4/inode.c:290 evict+0x4c9/0x8d0 fs/inode.c:650 iput_final fs/inode.c:1779 [inline] iput+0x635/0x7c0 fs/inode.c:1805 do_unlinkat+0x380/0x6d0 fs/namei.c:4363 __do_sys_unlink fs/namei.c:4404 [inline] __se_sys_unlink fs/namei.c:4402 [inline] __x64_sys_unlink+0x49/0x50 fs/namei.c:4402 x64_sys_call+0x878/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:88 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: 0033:0x7f95e7476fa7 Code: 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 57 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 RSP: 002b:00007ffdb912f058 EFLAGS: 00000206 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f95e7476fa7 RDX: 00007ffdb912f080 RSI: 00007ffdb912f110 RDI: 00007ffdb912f110 RBP: 00007ffdb912f110 R08: 00007ffdb9130110 R09: 00000000ffffffff R10: 0000000000000100 R11: 0000000000000206 R12: 00007ffdb9130200 R13: 00007f95e74e171f R14: 00000000000077de R15: 00007ffdb91312d0 The buggy address belongs to the page: page:ffffea0004ba27c0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x12e89f flags: 0x4000000000000000(zone=1) raw: 4000000000000000 ffffea0004ba2808 ffffea0004ba2788 0000000000000000 raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner info is not present (never set?) Memory state around the buggy address: ffff88812e89fc80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88812e89fd00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff88812e89fd80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff88812e89fe00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88812e89fe80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ================================================================== EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 3879242160, count = 16 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 3879209504, count = 32661 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 254253474022432, count = 16 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 254253474021269, count = 1168 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 254253474021264, count = 16 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 3879162320, count = 16 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 3879129664, count = 32661 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 254219114301920, count = 16 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 522107488, count = 16 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 522074961, count = 32534 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 522074960, count = 16 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 34213709527648, count = 16 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 34213709512470, count = 15185 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 34213709512464, count = 16 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 522107488, count = 16 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 522074961, count = 32534 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 36872832, count = 0 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 0, count = 16 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 0, count = 1 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 1114112, count = 192 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 2448131358720, count = 13888 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 1, count = 192 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 2392296784064, count = 31456 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 37369408, count = 0 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 36639264, count = 0 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 0, count = 16 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 0, count = 1 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 1114112, count = 192 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 2448131358720, count = 13888 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 1, count = 192 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 2383706849472, count = 22304 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 37369408, count = 0 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 1114113, count = 192 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 2448131358720, count = 13888 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 1, count = 0 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 0, count = 16 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 1460288880832, count = 17824 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 37369408, count = 0 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 37369408, count = 16 EXT4-fs error (device loop2): ext4_free_blocks:6234: comm syz-executor: Freeing blocks not in datazone - block = 0, count = 16