================================================================== BUG: KASAN: use-after-free in ext4_htree_fill_tree+0x106b/0x10d0 fs/ext4/namei.c:1246 Read of size 1 at addr ffff88811a462d1b by task syz-executor/467 CPU: 0 PID: 467 Comm: syz-executor Not tainted 5.15.189-syzkaller-1081280-gf32b52534f1d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: __dump_stack+0x21/0x30 lib/dump_stack.c:88 dump_stack_lvl+0xee/0x150 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+0x106b/0x10d0 fs/ext4/namei.c:1246 ext4_dx_readdir fs/ext4/dir.c:609 [inline] ext4_readdir+0x2bfd/0x3a40 fs/ext4/dir.c:145 iterate_dir+0x260/0x600 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+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: 0033:0x7fdb3397f753 Code: c1 66 0f 1f 44 00 00 48 83 c4 08 48 89 ef 5b 5d e9 52 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:00007fff4731fb18 EFLAGS: 00000293 ORIG_RAX: 00000000000000d9 RAX: ffffffffffffffda RBX: 00005555633244e0 RCX: 00007fdb3397f753 RDX: 0000000000008000 RSI: 00005555633244e0 RDI: 0000000000000005 RBP: 00005555633244b4 R08: 0000000000028b61 R09: 0000000000000000 R10: 00007fdb33b3cca0 R11: 0000000000000293 R12: ffffffffffffffa8 R13: 0000000000000010 R14: 00005555633244b0 R15: 00007fff47321dd0 Allocated by task 140: 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:3240 [inline] slab_alloc mm/slub.c:3250 [inline] kmem_cache_alloc+0xf7/0x260 mm/slub.c:3255 mempool_alloc_slab+0x1d/0x30 mm/mempool.c:513 mempool_alloc+0x159/0x4a0 mm/mempool.c:393 bio_alloc_bioset+0x136/0x940 block/bio.c:469 bio_alloc include/linux/bio.h:429 [inline] submit_bh_wbc+0x1c6/0x670 fs/buffer.c:3028 submit_bh+0x2a/0x40 fs/buffer.c:3062 __ext4_read_bh fs/ext4/super.c:155 [inline] ext4_read_bh+0x187/0x230 fs/ext4/super.c:179 ext4_read_bh_lock+0x7c/0xb0 fs/ext4/super.c:194 ext4_bread+0x132/0x180 fs/ext4/inode.c:930 __ext4_read_dirblock+0xd4/0x8e0 fs/ext4/namei.c:144 htree_dirblock_to_tree+0x279/0xe70 fs/ext4/namei.c:1083 ext4_htree_fill_tree+0x5d4/0x10d0 fs/ext4/namei.c:1220 ext4_dx_readdir fs/ext4/dir.c:609 [inline] ext4_readdir+0x2bfd/0x3a40 fs/ext4/dir.c:145 iterate_dir+0x260/0x600 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+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 The buggy address belongs to the object at ffff88811a462c80 which belongs to the cache bio-224 of size 224 The buggy address is located 155 bytes inside of 224-byte region [ffff88811a462c80, ffff88811a462d60) The buggy address belongs to the page: page:ffffea0004691880 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88811a462140 pfn:0x11a462 flags: 0x4000000000000200(slab|zone=1) raw: 4000000000000200 ffffea000468c840 0000000e0000000e ffff8881081aa180 raw: ffff88811a462140 00000000800c0000 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 0x92800(GFP_NOWAIT|__GFP_NOWARN|__GFP_NORETRY|__GFP_NOMEMALLOC), pid 131, ts 4872141587, free_ts 0 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+0x2cc5/0x2d50 mm/page_alloc.c:4485 __alloc_pages+0x18f/0x440 mm/page_alloc.c:5795 alloc_slab_page mm/slub.c:-1 [inline] allocate_slab mm/slub.c:1932 [inline] new_slab+0xa1/0x4d0 mm/slub.c:1995 ___slab_alloc+0x381/0x810 mm/slub.c:3028 __slab_alloc+0x49/0x90 mm/slub.c:3115 slab_alloc_node mm/slub.c:3206 [inline] slab_alloc mm/slub.c:3250 [inline] kmem_cache_alloc+0x138/0x260 mm/slub.c:3255 mempool_alloc_slab+0x1d/0x30 mm/mempool.c:513 mempool_alloc+0x159/0x4a0 mm/mempool.c:393 bio_alloc_bioset+0x136/0x940 block/bio.c:469 bio_alloc include/linux/bio.h:429 [inline] ext4_mpage_readpages+0x14b4/0x2050 fs/ext4/readpage.c:413 ext4_readahead+0xe4/0x110 fs/ext4/inode.c:3266 read_pages+0x16e/0xb00 mm/readahead.c:141 page_cache_ra_unbounded+0x782/0x980 mm/readahead.c:250 do_page_cache_ra mm/readahead.c:280 [inline] ondemand_readahead+0x8d3/0xe30 mm/readahead.c:565 page_owner free stack trace missing Memory state around the buggy address: ffff88811a462c00: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc ffff88811a462c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88811a462d00: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ^ ffff88811a462d80: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ffff88811a462e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== EXT4-fs error (device loop2): __ext4_get_inode_loc:4352: comm syz-executor: Invalid inode table block 14875662660405297151 in block_group 0 EXT4-fs error (device loop2) in ext4_reserve_inode_write:5867: Corrupt filesystem EXT4-fs error (device loop2): ext4_dirty_inode:6071: inode #2: comm syz-executor: mark_inode_dirty error