================================================================== BUG: KASAN: use-after-free in ext4_htree_fill_tree+0x1066/0x10d0 fs/ext4/namei.c:1246 Read of size 1 at addr ffff88811b602d1b by task syz-executor/479 CPU: 0 PID: 479 Comm: syz-executor Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: __dump_stack+0x21/0x24 lib/dump_stack.c:88 dump_stack_lvl+0xee/0x150 lib/dump_stack.c:106 print_address_description+0x71/0x200 mm/kasan/report.c:316 print_report+0x4a/0x60 mm/kasan/report.c:420 kasan_report+0x122/0x150 mm/kasan/report.c:524 __asan_report_load1_noabort+0x14/0x20 mm/kasan/report_generic.c:348 ext4_htree_fill_tree+0x1066/0x10d0 fs/ext4/namei.c:1246 ext4_dx_readdir fs/ext4/dir.c:608 [inline] ext4_readdir+0x2d8a/0x3c10 fs/ext4/dir.c:145 iterate_dir+0x271/0x610 fs/readdir.c:-1 __do_sys_getdents64 fs/readdir.c:369 [inline] __se_sys_getdents64+0xe5/0x240 fs/readdir.c:354 __x64_sys_getdents64+0x7b/0x90 fs/readdir.c:354 x64_sys_call+0x15c/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:218 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f31675bf693 Code: c1 66 0f 1f 44 00 00 48 83 c4 08 48 89 ef 5b 5d e9 82 3e f8 ff 66 90 b8 ff ff ff 7f 48 39 c2 48 0f 47 d0 b8 d9 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 05 c3 0f 1f 40 00 48 c7 c2 a8 ff ff ff f7 d8 RSP: 002b:00007ffe69c3fbd8 EFLAGS: 00000293 ORIG_RAX: 00000000000000d9 RAX: ffffffffffffffda RBX: 0000555559a4d4e0 RCX: 00007f31675bf693 RDX: 0000000000008000 RSI: 0000555559a4d4e0 RDI: 0000000000000005 RBP: 0000555559a4d4b4 R08: 0000000000028b61 R09: 0000000000000000 R10: 00007f316777cca0 R11: 0000000000000293 R12: ffffffffffffffa8 R13: 0000000000000010 R14: 0000555559a4d4b0 R15: 0000000000000001 Allocated by task 130: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 kasan_save_alloc_info+0x25/0x30 mm/kasan/generic.c:505 __kasan_slab_alloc+0x72/0x80 mm/kasan/common.c:333 kasan_slab_alloc include/linux/kasan.h:202 [inline] slab_post_alloc_hook+0x4f/0x2d0 mm/slab.h:768 slab_alloc_node mm/slub.c:3382 [inline] slab_alloc mm/slub.c:3392 [inline] __kmem_cache_alloc_lru mm/slub.c:3399 [inline] kmem_cache_alloc+0x16e/0x330 mm/slub.c:3408 vm_area_dup+0x27/0x280 kernel/fork.c:511 dup_mmap kernel/fork.c:724 [inline] dup_mm kernel/fork.c:1644 [inline] copy_mm+0xb45/0x1a10 kernel/fork.c:1696 copy_process+0x12b4/0x3480 kernel/fork.c:2459 kernel_clone+0x23a/0x810 kernel/fork.c:2874 __do_sys_clone kernel/fork.c:3017 [inline] __se_sys_clone kernel/fork.c:3001 [inline] __x64_sys_clone+0x168/0x1b0 kernel/fork.c:3001 x64_sys_call+0x990/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:57 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Freed by task 131: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x31/0x50 mm/kasan/generic.c:516 ____kasan_slab_free+0x132/0x180 mm/kasan/common.c:241 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:249 kasan_slab_free include/linux/kasan.h:178 [inline] slab_free_hook mm/slub.c:1750 [inline] slab_free_freelist_hook+0xc2/0x190 mm/slub.c:1776 slab_free mm/slub.c:3712 [inline] kmem_cache_free+0x12d/0x300 mm/slub.c:3737 __vm_area_free+0x7e/0x130 kernel/fork.c:537 remove_vma mm/mmap.c:153 [inline] exit_mmap+0x551/0xb60 mm/mmap.c:3392 __mmput+0x93/0x320 kernel/fork.c:1300 mmput+0x4b/0x150 kernel/fork.c:1323 exec_mmap fs/exec.c:1041 [inline] begin_new_exec+0x1672/0x2170 fs/exec.c:1301 load_elf_binary+0x99f/0x26d0 fs/binfmt_elf.c:1028 search_binary_handler fs/exec.c:1743 [inline] exec_binprm fs/exec.c:1784 [inline] bprm_execve+0x787/0x1440 fs/exec.c:1853 do_execveat_common+0x915/0xa70 fs/exec.c:1958 do_execve fs/exec.c:2032 [inline] __do_sys_execve fs/exec.c:2108 [inline] __se_sys_execve fs/exec.c:2103 [inline] __x64_sys_execve+0x92/0xb0 fs/exec.c:2103 x64_sys_call+0x98/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:60 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 The buggy address belongs to the object at ffff88811b602c60 which belongs to the cache vm_area_struct of size 200 The buggy address is located 187 bytes inside of 200-byte region [ffff88811b602c60, ffff88811b602d28) The buggy address belongs to the physical page: page:ffffea00046d8080 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11b602 flags: 0x4000000000000200(slab|zone=1) raw: 4000000000000200 0000000000000000 dead000000000122 ffff8881002aac00 raw: 0000000000000000 00000000000f000f 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 130, tgid 130 (S40network), ts 5348754932, free_ts 0 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x1f5/0x210 mm/page_alloc.c:2643 prep_new_page+0x1c/0x110 mm/page_alloc.c:2650 get_page_from_freelist+0x2c7b/0x2cf0 mm/page_alloc.c:4554 __alloc_pages+0x1c3/0x450 mm/page_alloc.c:5868 alloc_slab_page+0x6e/0xf0 include/linux/gfp.h:-1 allocate_slab mm/slub.c:1967 [inline] new_slab+0x98/0x3d0 mm/slub.c:2020 ___slab_alloc+0x6bd/0xb20 mm/slub.c:3177 __slab_alloc+0x5e/0xa0 mm/slub.c:3263 slab_alloc_node mm/slub.c:3348 [inline] slab_alloc mm/slub.c:3392 [inline] __kmem_cache_alloc_lru mm/slub.c:3399 [inline] kmem_cache_alloc+0x1b0/0x330 mm/slub.c:3408 vm_area_dup+0x27/0x280 kernel/fork.c:511 dup_mmap kernel/fork.c:724 [inline] dup_mm kernel/fork.c:1644 [inline] copy_mm+0xb45/0x1a10 kernel/fork.c:1696 copy_process+0x12b4/0x3480 kernel/fork.c:2459 kernel_clone+0x23a/0x810 kernel/fork.c:2874 __do_sys_clone kernel/fork.c:3017 [inline] __se_sys_clone kernel/fork.c:3001 [inline] __x64_sys_clone+0x168/0x1b0 kernel/fork.c:3001 x64_sys_call+0x990/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:57 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 page_owner free stack trace missing Memory state around the buggy address: ffff88811b602c00: fb fb fb fb fc fc fc fc fc fc fc fc fa fb fb fb ffff88811b602c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88811b602d00: fb fb fb fb fb fc fc fc fc fc fc fc fc fa fb fb ^ ffff88811b602d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88811b602e00: fb fb fb fb fb fb fc fc fc fc fc fc fc fc fa fb ================================================================== EXT4-fs error (device loop3): __ext4_get_inode_loc:4509: comm syz-executor: Invalid inode table block 14875662660405297151 in block_group 0 EXT4-fs error (device loop3) in ext4_reserve_inode_write:5917: Corrupt filesystem EXT4-fs error (device loop3): ext4_dirty_inode:6121: inode #2: comm syz-executor: mark_inode_dirty error EXT4-fs (loop3): unmounting filesystem.