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BUG: KASAN: slab-out-of-bounds in user_mode arch/x86/include/asm/ptrace.h:131 [inline]
BUG: KASAN: slab-out-of-bounds in trace_page_fault_entries arch/x86/mm/fault.c:1516 [inline]
BUG: KASAN: slab-out-of-bounds in do_page_fault+0x6d/0x320 arch/x86/mm/fault.c:1528
Read of size 8 at addr ffff8881e8cc7f20 by task syz.1.3266/11954

CPU: 0 PID: 11954 Comm: syz.1.3266 Tainted: G        W         5.4.292-syzkaller-00021-gcd8e74fa0fa3 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:

Allocated by task 0:
(stack is not available)

Freed by task 3905713712:
(stack is not available)

The buggy address belongs to the object at ffff8881e8cc6600
 which belongs to the cache names_cache of size 4096
The buggy address is located 2336 bytes to the right of
 4096-byte region [ffff8881e8cc6600, ffff8881e8cc7600)
The buggy address belongs to the page:
page:ffffea0007a33000 refcount:1 mapcount:0 mapping:ffff8881f5d00f00 index:0x0 compound_mapcount: 0
flags: 0x8000000000010200(slab|head)
raw: 8000000000010200 dead000000000100 dead000000000122 ffff8881f5d00f00
raw: 0000000000000000 0000000000070007 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL)
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook mm/page_alloc.c:2165 [inline]
 prep_new_page+0x35e/0x370 mm/page_alloc.c:2171
 get_page_from_freelist+0x1296/0x1310 mm/page_alloc.c:3794
 __alloc_pages_nodemask+0x202/0x4b0 mm/page_alloc.c:4894
 alloc_slab_page+0x3c/0x3b0 mm/slub.c:343
 allocate_slab mm/slub.c:1683 [inline]
 new_slab+0x93/0x420 mm/slub.c:1749
 new_slab_objects mm/slub.c:2505 [inline]
 ___slab_alloc+0x29e/0x420 mm/slub.c:2667
 __slab_alloc+0x63/0xa0 mm/slub.c:2707
 slab_alloc_node mm/slub.c:2792 [inline]
 slab_alloc mm/slub.c:2837 [inline]
 kmem_cache_alloc+0x12c/0x270 mm/slub.c:2842
 getname_flags+0xb9/0x500 fs/namei.c:141
 getname+0x19/0x20 fs/namei.c:212
 do_sys_open+0x26c/0x5d0 fs/open.c:1117
 __do_sys_openat fs/open.c:1150 [inline]
 __se_sys_openat fs/open.c:1144 [inline]
 __x64_sys_openat+0xa2/0xb0 fs/open.c:1144
 do_syscall_64+0xcf/0x170 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x5c/0xc1
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1176 [inline]
 __free_pages_ok+0x7e4/0x910 mm/page_alloc.c:1438
 free_the_page mm/page_alloc.c:4956 [inline]
 __free_pages+0x8c/0x110 mm/page_alloc.c:4962
 __free_slab+0x218/0x2d0 mm/slub.c:1774
 free_slab mm/slub.c:1789 [inline]
 discard_slab mm/slub.c:1795 [inline]
 unfreeze_partials+0x165/0x1a0 mm/slub.c:2288
 put_cpu_partial+0xc1/0x180 mm/slub.c:2324
 __slab_free+0x2be/0x380 mm/slub.c:2971
 do_slab_free mm/slub.c:3068 [inline]
 ___cache_free+0xbb/0xd0 mm/slub.c:3087
 qlink_free+0x23/0x30 mm/kasan/quarantine.c:148
 qlist_free_all+0x5f/0xb0 mm/kasan/quarantine.c:167
 quarantine_reduce+0x1a8/0x200 mm/kasan/quarantine.c:260
 __kasan_kmalloc+0x42/0x200 mm/kasan/common.c:507
 kasan_slab_alloc+0x12/0x20 mm/kasan/common.c:537
 slab_post_alloc_hook mm/slab.h:584 [inline]
 slab_alloc_node mm/slub.c:2829 [inline]
 slab_alloc mm/slub.c:2837 [inline]
 kmem_cache_alloc+0xe2/0x270 mm/slub.c:2842
 getname_flags+0xb9/0x500 fs/namei.c:141
 getname+0x19/0x20 fs/namei.c:212
 do_sys_open+0x26c/0x5d0 fs/open.c:1117

Memory state around the buggy address:
 ffff8881e8cc7e00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8881e8cc7e80: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
>ffff8881e8cc7f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                               ^
 ffff8881e8cc7f80: f1 f1 f1 f1 00 f2 f2 f2 04 f3 f3 f3 fc fc fc fc
 ffff8881e8cc8000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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