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BUG: KASAN: use-after-free in memcpy include/linux/fortify-string.h:191 [inline]
BUG: KASAN: use-after-free in __d_alloc+0x19a/0x950 fs/dcache.c:1775
Read of size 5 at addr ffff888078b92220 by task kdevtmpfs/22

CPU: 0 PID: 22 Comm: kdevtmpfs Not tainted 5.14.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 print_address_description.constprop.0.cold+0x6c/0x2d6 mm/kasan/report.c:256
 __kasan_report mm/kasan/report.c:442 [inline]
 kasan_report.cold+0x83/0xdf mm/kasan/report.c:459
 check_region_inline mm/kasan/generic.c:183 [inline]
 kasan_check_range+0x13d/0x180 mm/kasan/generic.c:189
 memcpy+0x20/0x60 mm/kasan/shadow.c:65
 memcpy include/linux/fortify-string.h:191 [inline]
 __d_alloc+0x19a/0x950 fs/dcache.c:1775
 d_alloc+0x4a/0x230 fs/dcache.c:1823
 __lookup_hash+0xc8/0x180 fs/namei.c:1554
 kern_path_locked+0x17e/0x320 fs/namei.c:2567
 handle_remove+0xa2/0x5fe drivers/base/devtmpfs.c:312
 handle drivers/base/devtmpfs.c:382 [inline]
 devtmpfs_work_loop drivers/base/devtmpfs.c:395 [inline]
 devtmpfsd+0x1b9/0x2a3 drivers/base/devtmpfs.c:437
 kthread+0x3e5/0x4d0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

Allocated by task 22:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 __kasan_slab_alloc+0x80/0xa0 mm/kasan/common.c:467
 kasan_slab_alloc include/linux/kasan.h:254 [inline]
 slab_post_alloc_hook mm/slab.h:519 [inline]
 slab_alloc mm/slab.c:3323 [inline]
 kmem_cache_alloc+0x25f/0x540 mm/slab.c:3507
 getname_kernel+0x4e/0x370 fs/namei.c:226
 kern_path_locked+0x71/0x320 fs/namei.c:2558
 handle_remove+0xa2/0x5fe drivers/base/devtmpfs.c:312
 handle drivers/base/devtmpfs.c:382 [inline]
 devtmpfs_work_loop drivers/base/devtmpfs.c:395 [inline]
 devtmpfsd+0x1b9/0x2a3 drivers/base/devtmpfs.c:437
 kthread+0x3e5/0x4d0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

Freed by task 22:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
 kasan_set_track+0x1c/0x30 mm/kasan/common.c:46
 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:360
 ____kasan_slab_free mm/kasan/common.c:366 [inline]
 ____kasan_slab_free mm/kasan/common.c:328 [inline]
 __kasan_slab_free+0xd1/0x110 mm/kasan/common.c:374
 kasan_slab_free include/linux/kasan.h:230 [inline]
 __cache_free mm/slab.c:3445 [inline]
 kmem_cache_free+0x6c/0x200 mm/slab.c:3740
 putname.part.0+0xe1/0x120 fs/namei.c:270
 putname include/linux/err.h:41 [inline]
 filename_parentat fs/namei.c:2547 [inline]
 kern_path_locked+0xc2/0x320 fs/namei.c:2558
 handle_remove+0xa2/0x5fe drivers/base/devtmpfs.c:312
 handle drivers/base/devtmpfs.c:382 [inline]
 devtmpfs_work_loop drivers/base/devtmpfs.c:395 [inline]
 devtmpfsd+0x1b9/0x2a3 drivers/base/devtmpfs.c:437
 kthread+0x3e5/0x4d0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

The buggy address belongs to the object at ffff888078b92200
 which belongs to the cache names_cache of size 4096
The buggy address is located 32 bytes inside of
 4096-byte region [ffff888078b92200, ffff888078b93200)
The buggy address belongs to the page:
page:ffffea0001e2e480 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x78b92
head:ffffea0001e2e480 order:1 compound_mapcount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 ffffea00021eb388 ffffea00020eb788 ffff8880114b9600
raw: 0000000000000000 ffff888078b92200 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 1, migratetype Unmovable, gfp_mask 0x2420c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_COMP|__GFP_THISNODE), pid 11726, ts 383931520064, free_ts 383886252256
 prep_new_page mm/page_alloc.c:2424 [inline]
 get_page_from_freelist+0xa72/0x2f80 mm/page_alloc.c:4153
 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5375
 __alloc_pages_node include/linux/gfp.h:570 [inline]
 kmem_getpages mm/slab.c:1377 [inline]
 cache_grow_begin+0x75/0x460 mm/slab.c:2593
 cache_alloc_refill+0x27f/0x380 mm/slab.c:2965
 ____cache_alloc mm/slab.c:3048 [inline]
 ____cache_alloc mm/slab.c:3031 [inline]
 __do_cache_alloc mm/slab.c:3275 [inline]
 slab_alloc mm/slab.c:3316 [inline]
 kmem_cache_alloc+0x454/0x540 mm/slab.c:3507
 getname_flags.part.0+0x50/0x4f0 fs/namei.c:138
 getname_flags include/linux/audit.h:319 [inline]
 getname fs/namei.c:217 [inline]
 __do_sys_unlink fs/namei.c:4217 [inline]
 __se_sys_unlink fs/namei.c:4215 [inline]
 __x64_sys_unlink+0xb1/0x110 fs/namei.c:4215
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1338 [inline]
 free_pcp_prepare+0x2c5/0x780 mm/page_alloc.c:1389
 free_unref_page_prepare mm/page_alloc.c:3315 [inline]
 free_unref_page+0x19/0x690 mm/page_alloc.c:3394
 slab_destroy mm/slab.c:1627 [inline]
 slabs_destroy+0x89/0xc0 mm/slab.c:1647
 cache_flusharray mm/slab.c:3418 [inline]
 ___cache_free+0x4c6/0x610 mm/slab.c:3480
 qlink_free mm/kasan/quarantine.c:146 [inline]
 qlist_free_all+0x4e/0x110 mm/kasan/quarantine.c:165
 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:272
 __kasan_slab_alloc+0x92/0xa0 mm/kasan/common.c:444
 kasan_slab_alloc include/linux/kasan.h:254 [inline]
 slab_post_alloc_hook mm/slab.h:519 [inline]
 slab_alloc mm/slab.c:3323 [inline]
 kmem_cache_alloc+0x25f/0x540 mm/slab.c:3507
 getname_flags.part.0+0x50/0x4f0 fs/namei.c:138
 getname_flags include/linux/audit.h:319 [inline]
 getname+0x8e/0xd0 fs/namei.c:217
 do_sys_openat2+0xf5/0x4d0 fs/open.c:1194
 do_sys_open fs/open.c:1216 [inline]
 __do_sys_open fs/open.c:1224 [inline]
 __se_sys_open fs/open.c:1220 [inline]
 __x64_sys_open+0x119/0x1c0 fs/open.c:1220
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Memory state around the buggy address:
 ffff888078b92100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888078b92180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888078b92200: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                               ^
 ffff888078b92280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888078b92300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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