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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:1516 [inline]
BUG: KASAN: use-after-free in do_page_fault+0x6d/0x320 arch/x86/mm/fault.c:1528
Read of size 8 at addr ffff8881dea1fee0 by task syz.3.220/1167

CPU: 1 PID: 1167 Comm: syz.3.220 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:

The buggy address belongs to the page:
page:ffffea00077a87c0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0
flags: 0x8000000000000000()
raw: 8000000000000000 ffffea00077b3608 ffffea00077a8788 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 0, migratetype Unmovable, gfp_mask 0x102dc2(GFP_HIGHUSER|__GFP_NOWARN|__GFP_ZERO)
 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_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]
 __vmalloc_area_node mm/vmalloc.c:-1 [inline]
 __vmalloc_node_range+0x36a/0x6e0 mm/vmalloc.c:2499
 vmalloc_user+0x73/0x80 mm/vmalloc.c:2629
 kcov_mmap+0x2b/0x120 kernel/kcov.c:450
 call_mmap include/linux/fs.h:1996 [inline]
 mmap_region+0x101b/0x15a0 mm/mmap.c:1812
 do_mmap+0x826/0xd90 mm/mmap.c:1581
 do_mmap_pgoff include/linux/mm.h:2480 [inline]
 vm_mmap_pgoff+0x195/0x230 mm/util.c:528
 ksys_mmap_pgoff+0x16f/0x1e0 mm/mmap.c:1631
 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:97 [inline]
 __se_sys_mmap arch/x86/kernel/sys_x86_64.c:88 [inline]
 __x64_sys_mmap+0xfa/0x110 arch/x86/kernel/sys_x86_64.c:88
 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_pcp_prepare mm/page_alloc.c:1233 [inline]
 free_unref_page_prepare+0x2a9/0x3a0 mm/page_alloc.c:3085
 free_unref_page mm/page_alloc.c:3134 [inline]
 free_the_page mm/page_alloc.c:4954 [inline]
 __free_pages+0xaa/0x110 mm/page_alloc.c:4962
 __vunmap+0x76a/0x8a0 mm/vmalloc.c:2260
 __vfree mm/vmalloc.c:2308 [inline]
 vfree+0x61/0x90 mm/vmalloc.c:2338
 kcov_mmap+0x8c/0x120 kernel/kcov.c:474
 call_mmap include/linux/fs.h:1996 [inline]
 mmap_region+0x101b/0x15a0 mm/mmap.c:1812
 do_mmap+0x826/0xd90 mm/mmap.c:1581
 do_mmap_pgoff include/linux/mm.h:2480 [inline]
 vm_mmap_pgoff+0x195/0x230 mm/util.c:528
 ksys_mmap_pgoff+0x16f/0x1e0 mm/mmap.c:1631
 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:97 [inline]
 __se_sys_mmap arch/x86/kernel/sys_x86_64.c:88 [inline]
 __x64_sys_mmap+0xfa/0x110 arch/x86/kernel/sys_x86_64.c:88
 do_syscall_64+0xcf/0x170 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x5c/0xc1

Memory state around the buggy address:
 ffff8881dea1fd80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8881dea1fe00: ff ff ff ff ff ff ff ff 00 00 00 00 00 00 00 00
>ffff8881dea1fe80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                                       ^
 ffff8881dea1ff00: ff ff ff ff ff ff ff ff f1 f1 f1 f1 00 f2 f2 f2
 ffff8881dea1ff80: 04 f3 f3 f3 ff ff ff ff ff ff ff ff ff ff ff ff
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