linux-kernel - [syzbot] [mm?] KCSAN: data-race in mprotect_fixup / page_vma_mapped

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Message-ID: <673488e4.050a0220.1324f8.0019.GAE@google.com>
Date: Wed, 13 Nov 2024 03:09:24 -0800
From: syzbot <syzbot+d7f40a3262f9ec8994ed@...kaller.appspotmail.com>
To: akpm@...ux-foundation.org, linux-kernel@...r.kernel.org, 
	linux-mm@...ck.org, syzkaller-bugs@...glegroups.com
Subject: [syzbot] [mm?] KCSAN: data-race in mprotect_fixup / page_vma_mapped_walk

Hello,

syzbot found the following issue on:

HEAD commit:    3022e9d00ebe Merge tag 'sched_ext-for-6.12-rc7-fixes' of g..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=15a441a7980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=29fedde79f609854
dashboard link: https://syzkaller.appspot.com/bug?extid=d7f40a3262f9ec8994ed
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/12ca7a216979/disk-3022e9d0.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/3afa2bcfd596/vmlinux-3022e9d0.xz
kernel image: https://storage.googleapis.com/syzbot-assets/a91dd258e5ba/bzImage-3022e9d0.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+d7f40a3262f9ec8994ed@...kaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in mprotect_fixup / page_vma_mapped_walk

write to 0xffff888114e57160 of 8 bytes by task 3992 on cpu 0:
 vm_flags_init include/linux/mm.h:862 [inline]
 vm_flags_reset include/linux/mm.h:874 [inline]
 mprotect_fixup+0x419/0x5e0 mm/mprotect.c:677
 do_mprotect_pkey+0x653/0x960 mm/mprotect.c:838
 __do_sys_mprotect mm/mprotect.c:859 [inline]
 __se_sys_mprotect mm/mprotect.c:856 [inline]
 __x64_sys_mprotect+0x48/0x60 mm/mprotect.c:856
 x64_sys_call+0x26cf/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:11
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888114e57160 of 8 bytes by task 3979 on cpu 1:
 is_vm_hugetlb_page include/linux/hugetlb_inline.h:11 [inline]
 page_vma_mapped_walk+0xa3/0x9f0 mm/page_vma_mapped.c:188
 remove_migration_pte+0x6f9/0x9c0 mm/migrate.c:253
 rmap_walk_anon+0x28f/0x440 mm/rmap.c:2635
 rmap_walk+0x5b/0x70 mm/rmap.c:2713
 remove_migration_ptes mm/migrate.c:373 [inline]
 migrate_folio_move mm/migrate.c:1388 [inline]
 migrate_pages_batch+0x1374/0x1910 mm/migrate.c:1898
 migrate_pages_sync mm/migrate.c:1964 [inline]
 migrate_pages+0xff1/0x1820 mm/migrate.c:2073
 do_mbind mm/mempolicy.c:1390 [inline]
 kernel_mbind mm/mempolicy.c:1533 [inline]
 __do_sys_mbind mm/mempolicy.c:1607 [inline]
 __se_sys_mbind+0xf76/0x1160 mm/mempolicy.c:1603
 __x64_sys_mbind+0x78/0x90 mm/mempolicy.c:1603
 x64_sys_call+0x2b4d/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:238
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000000000100077 -> 0x0000000000100070

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 3979 Comm: syz.3.175 Not tainted 6.12.0-rc7-syzkaller-00012-g3022e9d00ebe #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
==================================================================


---
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