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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 ffff8881e3dcfec0 by task syz.4.85/666

CPU: 0 PID: 666 Comm: syz.4.85 Not tainted 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 4294905952:
(stack is not available)

Freed by task 130:
(stack is not available)

The buggy address belongs to the object at ffff8881e3dce000
 which belongs to the cache kmalloc-4k of size 4096
The buggy address is located 3776 bytes to the right of
 4096-byte region [ffff8881e3dce000, ffff8881e3dcf000)
The buggy address belongs to the page:
page:ffffea00078f7200 refcount:1 mapcount:0 mapping:ffff8881f5c0c280 index:0x0 compound_mapcount: 0
flags: 0x8000000000010200(slab|head)
raw: 8000000000010200 0000000000000000 0000000100000001 ffff8881f5c0c280
raw: 0000000000000000 0000000000040004 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC)
 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_trace+0x130/0x290 mm/slub.c:2854
 kmalloc include/linux/slab.h:556 [inline]
 kzalloc include/linux/slab.h:690 [inline]
 uevent_show+0x160/0x340 drivers/base/core.c:1938
 dev_attr_show+0x56/0xd0 drivers/base/core.c:1647
 sysfs_kf_seq_show+0x263/0x3d0 fs/sysfs/file.c:61
 kernfs_seq_show+0x110/0x160 fs/kernfs/file.c:167
 seq_read+0x540/0xe50 fs/seq_file.c:232
 kernfs_fop_read+0x127/0x480 fs/kernfs/file.c:251
 __vfs_read+0xf9/0x5c0 fs/read_write.c:425
 vfs_read+0x15a/0x370 fs/read_write.c:461
page_owner free stack trace missing

Memory state around the buggy address:
 ffff8881e3dcfd80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8881e3dcfe00: fc fc fc fc 00 00 00 00 00 00 00 00 fc fc fc fc
>ffff8881e3dcfe80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                                           ^
 ffff8881e3dcff00: fc fc fc fc f1 f1 f1 f1 00 f2 f2 f2 04 f3 f3 f3
 ffff8881e3dcff80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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