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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 ffff8881e5bffe20 by task syz.1.56/682

CPU: 1 PID: 682 Comm: syz.1.56 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 0:
(stack is not available)

Freed by task 0:
(stack is not available)

The buggy address belongs to the object at ffff8881e5bffd80
 which belongs to the cache seq_file of size 128
The buggy address is located 32 bytes to the right of
 128-byte region [ffff8881e5bffd80, ffff8881e5bffe00)
The buggy address belongs to the page:
page:ffffea000796ffc0 refcount:1 mapcount:0 mapping:ffff8881f5d02000 index:0x0
flags: 0x8000000000000200(slab)
raw: 8000000000000200 dead000000000100 dead000000000122 ffff8881f5d02000
raw: 0000000000000000 0000000000150015 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)
 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
 kmem_cache_zalloc include/linux/slab.h:680 [inline]
 seq_open+0x61/0x160 fs/seq_file.c:60
 kernfs_fop_open+0x4da/0xb20 fs/kernfs/file.c:702
 do_dentry_open+0x8b5/0x1030 fs/open.c:806
 vfs_open+0x73/0x80 fs/open.c:920
 do_last fs/namei.c:3565 [inline]
 path_openat+0x2a5e/0x35c0 fs/namei.c:3683
 do_filp_open+0x1ae/0x3f0 fs/namei.c:3713
 do_sys_open+0x2bb/0x5d0 fs/open.c:1123
 __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
page_owner free stack trace missing

Memory state around the buggy address:
 ffff8881e5bffd00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff8881e5bffd80: 00 00 00 00 00 00 00 00 fb fb fb fb fb fb fb fb
>ffff8881e5bffe00: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
                               ^
 ffff8881e5bffe80: f1 f1 f1 f1 00 f2 f2 f2 04 f3 f3 f3 fc fc fc fc
 ffff8881e5bfff00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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