================================================================== BUG: KASAN: use-after-free in ext4_ext_rm_leaf fs/ext4/extents.c:2627 [inline] BUG: KASAN: use-after-free in ext4_ext_remove_space+0x3211/0x42f0 fs/ext4/extents.c:2965 Read of size 4 at addr ffff88806dd22c18 by task syz.0.24/6071 CPU: 0 UID: 0 PID: 6071 Comm: syz.0.24 Not tainted 6.15.0-syzkaller-12426-ge271ed52b344 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:408 [inline] print_report+0xd2/0x2b0 mm/kasan/report.c:521 kasan_report+0x118/0x150 mm/kasan/report.c:634 ext4_ext_rm_leaf fs/ext4/extents.c:2627 [inline] ext4_ext_remove_space+0x3211/0x42f0 fs/ext4/extents.c:2965 ext4_ext_truncate+0x17e/0x300 fs/ext4/extents.c:4484 ext4_truncate+0x9bb/0x1100 fs/ext4/inode.c:4574 ext4_truncate_failed_write fs/ext4/truncate.h:22 [inline] ext4_write_end+0x802/0xaa0 fs/ext4/inode.c:1465 ext4_da_write_end+0x91/0xcf0 fs/ext4/inode.c:3208 generic_perform_write+0x63b/0x910 mm/filemap.c:4133 ext4_buffered_write_iter+0xce/0x3a0 fs/ext4/file.c:299 ext4_file_write_iter+0x298/0x1bc0 fs/ext4/file.c:-1 do_iter_readv_writev+0x56e/0x7f0 fs/read_write.c:-1 vfs_writev+0x31a/0x960 fs/read_write.c:1057 do_pwritev fs/read_write.c:1153 [inline] __do_sys_pwritev2 fs/read_write.c:1211 [inline] __se_sys_pwritev2+0x179/0x290 fs/read_write.c:1202 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f93fdf8e929 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:00007f93fee53038 EFLAGS: 00000246 ORIG_RAX: 0000000000000148 RAX: ffffffffffffffda RBX: 00007f93fe1b6080 RCX: 00007f93fdf8e929 RDX: 0000000000000001 RSI: 00002000000001c0 RDI: 0000000000000005 RBP: 00007f93fe010b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000e7b R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f93fe1b6080 R15: 00007ffe74784bc8 The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x6dd22 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000000 dead000000000100 dead000000000122 0000000000000000 raw: 0000000000000000 0000000000000000 00000000ffffffff 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 0xcc0(GFP_KERNEL), pid 1, tgid 1 (swapper/0), ts 28312747758, free_ts 30336269364 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1704 split_free_pages+0xd7/0x2f0 mm/page_alloc.c:6604 alloc_contig_range_noprof+0xd29/0x1210 mm/page_alloc.c:6781 __alloc_contig_pages mm/page_alloc.c:6811 [inline] alloc_contig_pages_noprof+0x47b/0x5a0 mm/page_alloc.c:6893 debug_vm_pgtable_alloc_huge_page+0xb5/0x110 mm/debug_vm_pgtable.c:1076 init_args+0x95f/0xd70 mm/debug_vm_pgtable.c:1258 debug_vm_pgtable+0xc0/0x450 mm/debug_vm_pgtable.c:1296 do_one_initcall+0x233/0x820 init/main.c:1273 do_initcall_level+0x137/0x1f0 init/main.c:1335 do_initcalls+0x69/0xd0 init/main.c:1351 kernel_init_freeable+0x3d9/0x570 init/main.c:1583 kernel_init+0x1d/0x1d0 init/main.c:1473 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 page last free pid 1 tgid 1 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1248 [inline] __free_frozen_pages+0xc65/0xe60 mm/page_alloc.c:2706 __free_pages mm/page_alloc.c:5071 [inline] free_contig_range+0x1bd/0x4a0 mm/page_alloc.c:6927 destroy_args+0x7e/0x5d0 mm/debug_vm_pgtable.c:1009 debug_vm_pgtable+0x412/0x450 mm/debug_vm_pgtable.c:1389 do_one_initcall+0x233/0x820 init/main.c:1273 do_initcall_level+0x137/0x1f0 init/main.c:1335 do_initcalls+0x69/0xd0 init/main.c:1351 kernel_init_freeable+0x3d9/0x570 init/main.c:1583 kernel_init+0x1d/0x1d0 init/main.c:1473 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Memory state around the buggy address: ffff88806dd22b00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88806dd22b80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff88806dd22c00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff88806dd22c80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88806dd22d00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================