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BUG: KASAN: use-after-free in user_mode arch/x86/include/asm/ptrace.h:131 [inline]
BUG: KASAN: use-after-free in trace_page_fault_entries arch/x86/mm/fault.c:1541 [inline]
BUG: KASAN: use-after-free in do_page_fault+0x66/0x330 arch/x86/mm/fault.c:1553
Read of size 8 at addr ffff8881e015fe40 by task syz-executor.3/1246

CPU: 1 PID: 1246 Comm: syz-executor.3 Not tainted 5.4.268-syzkaller-00003-g2d5d8240a7cb #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call Trace:

The buggy address belongs to the page:
page:ffffea00078057c0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0
flags: 0x8000000000000000()
raw: 8000000000000000 0000000000000000 ffffea00078057c8 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 3, migratetype Unmovable, gfp_mask 0x500dc0(GFP_USER|__GFP_ZERO|__GFP_ACCOUNT)
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook mm/page_alloc.c:2165 [inline]
 prep_new_page+0x18f/0x370 mm/page_alloc.c:2171
 get_page_from_freelist+0x2d13/0x2d90 mm/page_alloc.c:3794
 __alloc_pages_nodemask+0x393/0x840 mm/page_alloc.c:4891
 __alloc_pages include/linux/gfp.h:503 [inline]
 __alloc_pages_node include/linux/gfp.h:516 [inline]
 alloc_pages_node include/linux/gfp.h:530 [inline]
 alloc_thread_stack_node kernel/fork.c:259 [inline]
 dup_task_struct+0x85/0x600 kernel/fork.c:886
 copy_process+0x56d/0x3230 kernel/fork.c:1889
 _do_fork+0x197/0x900 kernel/fork.c:2399
 __do_sys_clone kernel/fork.c:2557 [inline]
 __se_sys_clone kernel/fork.c:2538 [inline]
 __x64_sys_clone+0x26b/0x2c0 kernel/fork.c:2538
 do_syscall_64+0xca/0x1c0 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+0x847/0x950 mm/page_alloc.c:1438
 free_the_page mm/page_alloc.c:4953 [inline]
 __free_pages+0x91/0x140 mm/page_alloc.c:4959
 free_thread_stack kernel/fork.c:299 [inline]
 release_task_stack kernel/fork.c:439 [inline]
 put_task_stack+0x212/0x260 kernel/fork.c:450
 finish_task_switch+0x24a/0x590 kernel/sched/core.c:3479
 context_switch kernel/sched/core.c:3611 [inline]
 __schedule+0xb0d/0x1320 kernel/sched/core.c:4307
 schedule+0x12c/0x1d0 kernel/sched/core.c:4375
 freezable_schedule include/linux/freezer.h:172 [inline]
 futex_wait_queue_me+0x31f/0x690 kernel/futex.c:2743
 futex_wait+0x2f5/0x890 kernel/futex.c:2849
 do_futex+0x13c1/0x19f0 kernel/futex.c:3888
 __do_sys_futex kernel/futex.c:3949 [inline]
 __se_sys_futex+0x355/0x470 kernel/futex.c:3917
 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x5c/0xc1

Memory state around the buggy address:
 ffff8881e015fd00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8881e015fd80: ff ff ff ff ff ff ff ff 00 00 00 00 00 00 00 00
>ffff8881e015fe00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                           ^
 ffff8881e015fe80: ff ff ff ff f1 f1 f1 f1 00 f2 f2 f2 04 f3 f3 f3
 ffff8881e015ff00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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