==================================================================
BUG: KASAN: use-after-free in ext4_search_dir+0xf7/0x1b0 fs/ext4/namei.c:1516
Read of size 1 at addr ffff88811a258900 by task syz.6.15/530

CPU: 1 PID: 530 Comm: syz.6.15 Not tainted 5.10.226-syzkaller-1003449-g6a01908517df #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack_lvl+0x1e2/0x24b lib/dump_stack.c:118
 print_address_description+0x81/0x3b0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:435 [inline]
 kasan_report+0x179/0x1c0 mm/kasan/report.c:452
 __asan_report_load1_noabort+0x14/0x20 mm/kasan/report_generic.c:306
 ext4_search_dir+0xf7/0x1b0 fs/ext4/namei.c:1516
 ext4_find_inline_entry+0x4b6/0x5e0 fs/ext4/inline.c:1700
 __ext4_find_entry+0x2b0/0x1990 fs/ext4/namei.c:1589
 ext4_lookup_entry fs/ext4/namei.c:1744 [inline]
 ext4_lookup+0x3c6/0xaa0 fs/ext4/namei.c:1812
 __lookup_hash+0x143/0x290 fs/namei.c:1541
 filename_create+0x202/0x750 fs/namei.c:3608
 user_path_create fs/namei.c:3665 [inline]
 do_mknodat+0x187/0x450 fs/namei.c:3729
 __do_sys_mknod fs/namei.c:3768 [inline]
 __se_sys_mknod fs/namei.c:3766 [inline]
 __x64_sys_mknod+0x80/0x90 fs/namei.c:3766
 do_syscall_64+0x34/0x70
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f3ea4dd8719
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:00007f3ea4859038 EFLAGS: 00000246 ORIG_RAX: 0000000000000085
RAX: ffffffffffffffda RBX: 00007f3ea4f8ff80 RCX: 00007f3ea4dd8719
RDX: 000000000000070d RSI: 0000000000000000 RDI: 0000000020000000
RBP: 00007f3ea4e4b32e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f3ea4f8ff80 R15: 00007ffc8306b888

Allocated by task 191:
 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:430 [inline]
 __kasan_slab_alloc+0xb1/0xe0 mm/kasan/common.c:463
 kasan_slab_alloc include/linux/kasan.h:244 [inline]
 slab_post_alloc_hook+0x61/0x2f0 mm/slab.h:583
 slab_alloc_node mm/slub.c:2947 [inline]
 slab_alloc mm/slub.c:2955 [inline]
 kmem_cache_alloc+0x168/0x2e0 mm/slub.c:2960
 kmem_cache_zalloc include/linux/slab.h:654 [inline]
 lsm_file_alloc security/security.c:535 [inline]
 security_file_alloc+0x29/0x120 security/security.c:1444
 __alloc_file+0xbf/0x330 fs/file_table.c:106
 alloc_empty_file+0x95/0x180 fs/file_table.c:151
 path_openat+0x105/0x3000 fs/namei.c:3495
 do_filp_open+0x21c/0x460 fs/namei.c:3536
 do_sys_openat2+0x13f/0x710 fs/open.c:1217
 do_sys_open fs/open.c:1233 [inline]
 __do_sys_openat fs/open.c:1249 [inline]
 __se_sys_openat fs/open.c:1244 [inline]
 __x64_sys_openat+0x243/0x290 fs/open.c:1244
 do_syscall_64+0x34/0x70
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

The buggy address belongs to the object at ffff88811a258900
 which belongs to the cache lsm_file_cache of size 16
The buggy address is located 0 bytes inside of
 16-byte region [ffff88811a258900, ffff88811a258910)
The buggy address belongs to the page:
page:ffffea0004689600 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88811a258cc0 pfn:0x11a258
flags: 0x4000000000000200(slab)
raw: 4000000000000200 ffffea000468ea00 0000001500000015 ffff888100190f00
raw: ffff88811a258cc0 0000000080800014 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 133, ts 5708064995, free_ts 5707537328
 set_page_owner include/linux/page_owner.h:35 [inline]
 post_alloc_hook mm/page_alloc.c:2456 [inline]
 prep_new_page+0x166/0x180 mm/page_alloc.c:2462
 get_page_from_freelist+0x2d8c/0x2f30 mm/page_alloc.c:4254
 __alloc_pages_nodemask+0x435/0xaf0 mm/page_alloc.c:5348
 allocate_slab mm/slub.c:1808 [inline]
 new_slab+0x80/0x400 mm/slub.c:1869
 new_slab_objects mm/slub.c:2627 [inline]
 ___slab_alloc+0x302/0x4b0 mm/slub.c:2791
 __slab_alloc+0x63/0xa0 mm/slub.c:2831
 slab_alloc_node mm/slub.c:2913 [inline]
 slab_alloc mm/slub.c:2955 [inline]
 kmem_cache_alloc+0x1b9/0x2e0 mm/slub.c:2960
 kmem_cache_zalloc include/linux/slab.h:654 [inline]
 lsm_file_alloc security/security.c:535 [inline]
 security_file_alloc+0x29/0x120 security/security.c:1444
 __alloc_file+0xbf/0x330 fs/file_table.c:106
 alloc_empty_file+0x95/0x180 fs/file_table.c:151
 path_openat+0x105/0x3000 fs/namei.c:3495
 do_filp_open+0x21c/0x460 fs/namei.c:3536
 do_sys_openat2+0x13f/0x710 fs/open.c:1217
 do_sys_open fs/open.c:1233 [inline]
 __do_sys_openat fs/open.c:1249 [inline]
 __se_sys_openat fs/open.c:1244 [inline]
 __x64_sys_openat+0x243/0x290 fs/open.c:1244
 do_syscall_64+0x34/0x70
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:28 [inline]
 free_pages_prepare mm/page_alloc.c:1349 [inline]
 free_pcp_prepare mm/page_alloc.c:1421 [inline]
 free_unref_page_prepare+0x2ae/0x2d0 mm/page_alloc.c:3336
 free_unref_page mm/page_alloc.c:3391 [inline]
 free_the_page+0x9e/0x370 mm/page_alloc.c:5407
 __free_pages+0x67/0xc0 mm/page_alloc.c:5418
 free_pages+0x7c/0x90 mm/page_alloc.c:5429
 selinux_genfs_get_sid+0x24d/0x2a0 security/selinux/hooks.c:1326
 inode_doinit_with_dentry+0x86f/0x1050 security/selinux/hooks.c:1523
 selinux_d_instantiate+0x27/0x40 security/selinux/hooks.c:6389
 security_d_instantiate+0x9f/0x100 security/security.c:1980
 d_splice_alias+0x6d/0x390 fs/dcache.c:3036
 proc_lookup_de+0x295/0x300 fs/proc/generic.c:263
 proc_tgid_net_lookup+0x60/0xf0 fs/proc/proc_net.c:286
 lookup_open fs/namei.c:3226 [inline]
 open_last_lookups fs/namei.c:3317 [inline]
 path_openat+0x11ab/0x3000 fs/namei.c:3506
 do_filp_open+0x21c/0x460 fs/namei.c:3536
 do_sys_openat2+0x13f/0x710 fs/open.c:1217
 do_sys_open fs/open.c:1233 [inline]
 __do_sys_openat fs/open.c:1249 [inline]
 __se_sys_openat fs/open.c:1244 [inline]
 __x64_sys_openat+0x243/0x290 fs/open.c:1244
 do_syscall_64+0x34/0x70

Memory state around the buggy address:
 ffff88811a258800: 00 00 fc fc fb fb fc fc fb fb fc fc fa fb fc fc
 ffff88811a258880: fb fb fc fc fb fb fc fc fb fb fc fc fb fb fc fc
>ffff88811a258900: fb fb fc fc fb fb fc fc fb fb fc fc fb fb fc fc
                   ^
 ffff88811a258980: fb fb fc fc fb fb fc fc fb fb fc fc fb fb fc fc
 ffff88811a258a00: fb fb fc fc fb fb fc fc fb fb fc fc fb fb fc fc
==================================================================
EXT4-fs error (device loop6): ext4_find_dest_de:2077: inode #12: block 7: comm syz.6.15: bad entry in directory: directory entry overrun - offset=0, inode=1793120026, rec_len=34652, size=56 fake=0