================================================================== BUG: KASAN: use-after-free in ext4_htree_fill_tree+0x10f5/0x1160 fs/ext4/namei.c:1246 Read of size 1 at addr ffff88811add5d1b by task syz-executor/450 CPU: 0 PID: 450 Comm: syz-executor Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 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_load1_noabort+0x14/0x20 mm/kasan/report_generic.c:306 ext4_htree_fill_tree+0x10f5/0x1160 fs/ext4/namei.c:1246 ext4_dx_readdir fs/ext4/dir.c:609 [inline] ext4_readdir+0x2cdb/0x3b20 fs/ext4/dir.c:145 iterate_dir+0x260/0x600 fs/readdir.c:-1 __do_sys_getdents64 fs/readdir.c:369 [inline] __se_sys_getdents64+0xf2/0x250 fs/readdir.c:354 __x64_sys_getdents64+0x7b/0x90 fs/readdir.c:354 x64_sys_call+0x592/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:218 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: 0033:0x7fe57339dd73 Code: c7 c0 e8 ff ff ff 64 c7 00 16 00 00 00 31 c0 eb 9e e8 81 9b fd ff 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 e8 ff ff ff f7 d8 RSP: 002b:00007ffc9e908608 EFLAGS: 00000293 ORIG_RAX: 00000000000000d9 RAX: ffffffffffffffda RBX: 000055557361d910 RCX: 00007fe57339dd73 RDX: 0000000000008000 RSI: 000055557361d940 RDI: 0000000000000005 RBP: 000055557361d940 R08: 0000000000028701 R09: 0000000000000001 R10: 00007fe573548ca0 R11: 0000000000000293 R12: 000055557361d914 R13: ffffffffffffffe8 R14: 0000000000000010 R15: 0000000000000001 Allocated by task 182: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:45 [inline] set_alloc_info mm/kasan/common.c:433 [inline] __kasan_slab_alloc+0xbd/0xf0 mm/kasan/common.c:466 kasan_slab_alloc include/linux/kasan.h:217 [inline] slab_post_alloc_hook+0x4f/0x2b0 mm/slab.h:550 slab_alloc_node mm/slub.c:3245 [inline] slab_alloc mm/slub.c:3255 [inline] kmem_cache_alloc+0xf7/0x260 mm/slub.c:3260 vm_area_dup+0x26/0x210 kernel/fork.c:368 __split_vma+0xac/0x3e0 mm/mmap.c:2753 __do_munmap+0x43e/0x1020 mm/mmap.c:2891 do_munmap mm/mmap.c:2936 [inline] munmap_vma_range mm/mmap.c:606 [inline] __mmap_region mm/mmap.c:1769 [inline] mmap_region+0x91e/0x1710 mm/mmap.c:2959 do_mmap+0x812/0xf10 mm/mmap.c:1598 vm_mmap_pgoff+0x1ec/0x430 mm/util.c:555 ksys_mmap_pgoff+0x161/0x1d0 mm/mmap.c:1647 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:93 [inline] __se_sys_mmap arch/x86/kernel/sys_x86_64.c:86 [inline] __x64_sys_mmap+0xfa/0x110 arch/x86/kernel/sys_x86_64.c:86 x64_sys_call+0x83/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:10 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 Freed by task 13: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4a/0x70 mm/kasan/common.c:45 kasan_set_free_info+0x23/0x40 mm/kasan/generic.c:370 ____kasan_slab_free+0x125/0x160 mm/kasan/common.c:365 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:373 kasan_slab_free include/linux/kasan.h:193 [inline] slab_free_hook mm/slub.c:1728 [inline] slab_free_freelist_hook+0xc2/0x190 mm/slub.c:1754 slab_free mm/slub.c:3526 [inline] kmem_cache_free+0x100/0x320 mm/slub.c:3544 __free_vm_area_struct+0x1c/0x20 kernel/fork.c:390 rcu_do_batch+0x532/0xbe0 kernel/rcu/tree.c:2523 rcu_core+0x5ee/0xf80 kernel/rcu/tree.c:2763 rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2776 handle_softirqs+0x250/0x560 kernel/softirq.c:583 run_ksoftirqd+0x28/0x40 kernel/softirq.c:959 smpboot_thread_fn+0x45a/0x8c0 kernel/smpboot.c:164 kthread+0x411/0x500 kernel/kthread.c:337 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Last potentially related work creation: kasan_save_stack+0x3a/0x60 mm/kasan/common.c:38 __kasan_record_aux_stack+0xd2/0x100 mm/kasan/generic.c:348 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:358 __call_rcu_common kernel/rcu/tree.c:3011 [inline] call_rcu+0x10b/0xf80 kernel/rcu/tree.c:3129 free_vm_area_struct kernel/fork.c:395 [inline] vm_area_free_no_check+0x10e/0x140 kernel/fork.c:409 vm_area_free+0x56/0x60 kernel/fork.c:419 remove_vma mm/mmap.c:191 [inline] remove_vma_list mm/mmap.c:2651 [inline] __do_munmap+0xc3d/0x1020 mm/mmap.c:2928 do_munmap mm/mmap.c:2936 [inline] munmap_vma_range mm/mmap.c:606 [inline] __mmap_region mm/mmap.c:1769 [inline] mmap_region+0x91e/0x1710 mm/mmap.c:2959 do_mmap+0x812/0xf10 mm/mmap.c:1598 vm_mmap_pgoff+0x1ec/0x430 mm/util.c:555 ksys_mmap_pgoff+0x161/0x1d0 mm/mmap.c:1647 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:93 [inline] __se_sys_mmap arch/x86/kernel/sys_x86_64.c:86 [inline] __x64_sys_mmap+0xfa/0x110 arch/x86/kernel/sys_x86_64.c:86 x64_sys_call+0x83/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:10 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 The buggy address belongs to the object at ffff88811add5cb8 which belongs to the cache vm_area_struct of size 232 The buggy address is located 99 bytes inside of 232-byte region [ffff88811add5cb8, ffff88811add5da0) The buggy address belongs to the page: page:ffffea00046b7540 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11add5 flags: 0x4000000000000200(slab|zone=1) raw: 4000000000000200 0000000000000000 dead000000000122 ffff888100186600 raw: 0000000000000000 00000000000d000d 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 182, ts 5748678680, free_ts 5746744499 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_slab_page mm/slub.c:-1 [inline] allocate_slab mm/slub.c:1937 [inline] new_slab+0xa1/0x4d0 mm/slub.c:2000 ___slab_alloc+0x381/0x810 mm/slub.c:3033 __slab_alloc+0x49/0x90 mm/slub.c:3120 slab_alloc_node mm/slub.c:3211 [inline] slab_alloc mm/slub.c:3255 [inline] kmem_cache_alloc+0x138/0x260 mm/slub.c:3260 vm_area_alloc+0x24/0x130 kernel/fork.c:360 __mmap_region mm/mmap.c:1794 [inline] mmap_region+0xaa6/0x1710 mm/mmap.c:2959 do_mmap+0x812/0xf10 mm/mmap.c:1598 vm_mmap_pgoff+0x1ec/0x430 mm/util.c:555 ksys_mmap_pgoff+0x161/0x1d0 mm/mmap.c:1647 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:93 [inline] __se_sys_mmap arch/x86/kernel/sys_x86_64.c:86 [inline] __x64_sys_mmap+0xfa/0x110 arch/x86/kernel/sys_x86_64.c:86 x64_sys_call+0x83/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:10 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 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 exec_mmap+0x422/0x4e0 fs/exec.c:1047 begin_new_exec+0xa8b/0x1ea0 fs/exec.c:1306 load_elf_binary+0x99c/0x28e0 fs/binfmt_elf.c:1001 search_binary_handler fs/exec.c:1755 [inline] exec_binprm fs/exec.c:1796 [inline] bprm_execve+0x7af/0x1490 fs/exec.c:1865 do_execveat_common+0x923/0xa80 fs/exec.c:1970 do_execve fs/exec.c:2040 [inline] __do_sys_execve fs/exec.c:2116 [inline] __se_sys_execve fs/exec.c:2111 [inline] __x64_sys_execve+0x92/0xb0 fs/exec.c:2111 x64_sys_call+0x919/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:60 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 Memory state around the buggy address: ffff88811add5c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc ffff88811add5c80: fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb fb >ffff88811add5d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88811add5d80: fb fb fb fb fc fc fc fc fc fc fc fc fa fb fb fb ffff88811add5e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== EXT4-fs error (device loop1): __ext4_get_inode_loc:4358: comm syz-executor: Invalid inode table block 14875662660405297151 in block_group 0 EXT4-fs error (device loop1) in ext4_reserve_inode_write:5885: Corrupt filesystem EXT4-fs error (device loop1): ext4_dirty_inode:6089: inode #2: comm syz-executor: mark_inode_dirty error