KASAN: invalid-free in ___pte_free_tlb

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syzbot

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Jan 9, 2022, 10:47:19 PM1/9/22
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Hello,

syzbot found the following issue on:

HEAD commit: 3f8a27f9e27b Linux 4.19.211
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1294b003b00000
kernel config: https://syzkaller.appspot.com/x/.config?x=9b9277b418617afe
dashboard link: https://syzkaller.appspot.com/bug?extid=08ba583a82ef7296cba3
compiler: gcc version 10.2.1 20210110 (Debian 10.2.1-6)

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+08ba58...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: double-free or invalid-free in pte_lock_deinit include/linux/mm.h:1910 [inline]
BUG: KASAN: double-free or invalid-free in pgtable_page_dtor include/linux/mm.h:1943 [inline]
BUG: KASAN: double-free or invalid-free in ___pte_free_tlb+0x40/0x190 arch/x86/mm/pgtable.c:64

CPU: 1 PID: 15619 Comm: syz-executor.0 Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1fc/0x2ef lib/dump_stack.c:118
print_address_description.cold+0x54/0x219 mm/kasan/report.c:256
kasan_report_invalid_free+0x61/0xa0 mm/kasan/report.c:336
__kasan_slab_free+0x1d0/0x1f0 mm/kasan/kasan.c:501
__cache_free mm/slab.c:3503 [inline]
kmem_cache_free+0x7f/0x260 mm/slab.c:3765
pte_lock_deinit include/linux/mm.h:1910 [inline]
pgtable_page_dtor include/linux/mm.h:1943 [inline]
___pte_free_tlb+0x40/0x190 arch/x86/mm/pgtable.c:64
__pte_free_tlb arch/x86/include/asm/pgalloc.h:73 [inline]
free_pte_range mm/memory.c:457 [inline]
free_pmd_range mm/memory.c:475 [inline]
free_pud_range mm/memory.c:509 [inline]
free_p4d_range mm/memory.c:543 [inline]
free_pgd_range+0xa94/0x1020 mm/memory.c:623
free_pgtables+0x230/0x2f0 mm/memory.c:655
exit_mmap+0x2c8/0x530 mm/mmap.c:3094
__mmput kernel/fork.c:1016 [inline]
mmput+0x14e/0x4a0 kernel/fork.c:1037
exit_mm kernel/exit.c:549 [inline]
do_exit+0xaec/0x2be0 kernel/exit.c:857
do_group_exit+0x125/0x310 kernel/exit.c:967
__do_sys_exit_group kernel/exit.c:978 [inline]
__se_sys_exit_group kernel/exit.c:976 [inline]
__x64_sys_exit_group+0x3a/0x50 kernel/exit.c:976
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7ff228164e99
Code: Bad RIP value.
RSP: 002b:00007fffc8bdaed8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 000000000000001e RCX: 00007ff228164e99
RDX: 00007ff228117adb RSI: ffffffffffffffbc RDI: 0000000000000000
RBP: 0000000000000000 R08: 00000000d02f5a14 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 0000000000000000 R14: 0000000000000001 R15: 00007fffc8bdafc0

Allocated by task 21795:
kmem_cache_alloc+0x122/0x370 mm/slab.c:3559
ptlock_alloc+0x1d/0x70 mm/memory.c:4969
ptlock_init include/linux/mm.h:1900 [inline]
pgtable_page_ctor include/linux/mm.h:1934 [inline]
pte_alloc_one+0x68/0x190 arch/x86/mm/pgtable.c:38
__pte_alloc+0x21/0x340 mm/memory.c:665
copy_pte_range mm/memory.c:1089 [inline]
copy_pmd_range mm/memory.c:1165 [inline]
copy_pud_range mm/memory.c:1199 [inline]
copy_p4d_range mm/memory.c:1221 [inline]
copy_page_range+0x1d3d/0x2ff0 mm/memory.c:1283
dup_mmap kernel/fork.c:549 [inline]
dup_mm kernel/fork.c:1285 [inline]
copy_mm kernel/fork.c:1341 [inline]
copy_process.part.0+0x5b22/0x8260 kernel/fork.c:1913
copy_process kernel/fork.c:1710 [inline]
_do_fork+0x22f/0xf30 kernel/fork.c:2219
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 15619:
__cache_free mm/slab.c:3503 [inline]
kmem_cache_free+0x7f/0x260 mm/slab.c:3765
pte_lock_deinit include/linux/mm.h:1910 [inline]
pgtable_page_dtor include/linux/mm.h:1943 [inline]
___pte_free_tlb+0x40/0x190 arch/x86/mm/pgtable.c:64
__pte_free_tlb arch/x86/include/asm/pgalloc.h:73 [inline]
free_pte_range mm/memory.c:457 [inline]
free_pmd_range mm/memory.c:475 [inline]
free_pud_range mm/memory.c:509 [inline]
free_p4d_range mm/memory.c:543 [inline]
free_pgd_range+0xa94/0x1020 mm/memory.c:623
free_pgtables+0x230/0x2f0 mm/memory.c:655
exit_mmap+0x2c8/0x530 mm/mmap.c:3094
__mmput kernel/fork.c:1016 [inline]
mmput+0x14e/0x4a0 kernel/fork.c:1037
exit_mm kernel/exit.c:549 [inline]
do_exit+0xaec/0x2be0 kernel/exit.c:857
do_group_exit+0x125/0x310 kernel/exit.c:967
__do_sys_exit_group kernel/exit.c:978 [inline]
__se_sys_exit_group kernel/exit.c:976 [inline]
__x64_sys_exit_group+0x3a/0x50 kernel/exit.c:976
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff88800010f000
which belongs to the cache page->ptl of size 56
The buggy address is located 0 bytes inside of
56-byte region [ffff88800010f000, ffff88800010f038)
The buggy address belongs to the page:
page:ffffea00000043c0 count:1 mapcount:0 mapping:ffff88813bfec040 index:0x0
flags: 0x7ff00000000100(slab)
raw: 007ff00000000100 ffffea00025e08c8 ffffea000061bb08 ffff88813bfec040
raw: 0000000000000000 ffff88800010f000 000000010000002e 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
ffff88800010ef00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff88800010ef80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88800010f000: fb fb fb fb fb fb fb fc fc fc fc fb fb fb fb fb
^
ffff88800010f080: fb fb fc fc fc fc fb fb fb fb fb fb fb fc fc fc
ffff88800010f100: fc fb fb fb fb fb fb fb fc fc fc fc fb fb fb fb
==================================================================


---
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syzbot

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May 9, 2022, 11:47:21 PM5/9/22
to syzkaller...@googlegroups.com
Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.
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