EXT4-fs warning (device loop2): dx_probe:833: inode #2: comm syz.2.17: Unrecognised inode hash code 20 EXT4-fs warning (device loop2): dx_probe:966: inode #2: comm syz.2.17: Corrupt directory, running e2fsck is recommended ================================================================== BUG: KASAN: use-after-free in __ext4_check_dir_entry+0x7c2/0x970 fs/ext4/dir.c:85 Read of size 2 at addr ffff888114763003 by task syz.2.17/378 CPU: 1 PID: 378 Comm: syz.2.17 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 Call Trace: __dump_stack+0x21/0x24 lib/dump_stack.c:88 dump_stack_lvl+0x110/0x170 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_load2_noabort+0x14/0x20 mm/kasan/report_generic.c:349 __ext4_check_dir_entry+0x7c2/0x970 fs/ext4/dir.c:85 ext4_readdir+0x1315/0x3e10 fs/ext4/dir.c:261 iterate_dir+0x271/0x610 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+0x15c/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:218 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fda30b9bf79 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fda319b3028 EFLAGS: 00000246 ORIG_RAX: 00000000000000d9 RAX: ffffffffffffffda RBX: 00007fda30e15fa0 RCX: 00007fda30b9bf79 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000006 RBP: 00007fda30c327e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fda30e16038 R14: 00007fda30e15fa0 R15: 00007ffd6fd34ca8 Allocated by task 111: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 kasan_save_alloc_info+0x25/0x30 mm/kasan/generic.c:505 ____kasan_kmalloc mm/kasan/common.c:380 [inline] __kasan_kmalloc+0x95/0xb0 mm/kasan/common.c:389 kasan_kmalloc include/linux/kasan.h:212 [inline] kmalloc_trace+0x40/0xb0 mm/slab_common.c:1033 kmalloc include/linux/slab.h:563 [inline] kzalloc include/linux/slab.h:699 [inline] kernfs_fop_open+0x371/0xb80 fs/kernfs/file.c:690 do_dentry_open+0x88e/0x1260 fs/open.c:884 vfs_open+0x73/0x80 fs/open.c:1017 do_open fs/namei.c:3633 [inline] path_openat+0x2700/0x2f80 fs/namei.c:3790 do_filp_open+0x1f1/0x430 fs/namei.c:3817 do_sys_openat2+0x15e/0x810 fs/open.c:1343 do_sys_open fs/open.c:1359 [inline] __do_sys_openat fs/open.c:1375 [inline] __se_sys_openat fs/open.c:1370 [inline] __x64_sys_openat+0x136/0x160 fs/open.c:1370 x64_sys_call+0x783/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:258 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 The buggy address belongs to the object at ffff888114763000 which belongs to the cache kmalloc-192 of size 192 The buggy address is located 3 bytes inside of 192-byte region [ffff888114763000, ffff8881147630c0) The buggy address belongs to the physical page: page:ffffea000451d8c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888114763900 pfn:0x114763 flags: 0x4000000000000200(slab|zone=1) raw: 4000000000000200 ffffea000451d708 ffffea000451dac8 ffff888100042c00 raw: ffff888114763900 0000000000100000 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 111, tgid 111 (udevadm), ts 4774489194, 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+0x2d12/0x2d80 mm/page_alloc.c:4554 __alloc_pages+0x1d9/0x480 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] __kmem_cache_alloc_node+0x203/0x2c0 mm/slub.c:3423 kmalloc_trace+0x29/0xb0 mm/slab_common.c:1028 kmalloc include/linux/slab.h:563 [inline] kzalloc include/linux/slab.h:699 [inline] kernfs_fop_open+0x371/0xb80 fs/kernfs/file.c:690 do_dentry_open+0x88e/0x1260 fs/open.c:884 vfs_open+0x73/0x80 fs/open.c:1017 do_open fs/namei.c:3633 [inline] path_openat+0x2700/0x2f80 fs/namei.c:3790 do_filp_open+0x1f1/0x430 fs/namei.c:3817 do_sys_openat2+0x15e/0x810 fs/open.c:1343 page_owner free stack trace missing Memory state around the buggy address: ffff888114762f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888114762f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888114763000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888114763080: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff888114763100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== EXT4-fs error (device loop2): ext4_readdir:263: inode #2: block 3: comm syz.2.17: path /0/file0: bad entry in directory: directory entry overrun - offset=2047, inode=1942470656, rec_len=33044, size=2048 fake=0 EXT4-fs error (device loop2) in ext4_reserve_inode_write:5930: Corrupt filesystem EXT4-fs error (device loop2): ext4_dirty_inode:6134: inode #2: comm syz.2.17: mark_inode_dirty error