From: syzbot <syzbot+395b7abe9696862fc188@syzkaller.appspotmail.com>
To: akpm@linux-foundation.org, david@kernel.org, harry@kernel.org,
jannh@google.com, liam@infradead.org,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
ljs@kernel.org, riel@surriel.com,
syzkaller-bugs@googlegroups.com, vbabka@kernel.org
Subject: [syzbot] [mm?] KCSAN: data-race in __anon_vma_prepare / __vmf_anon_prepare (2)
Date: Fri, 19 Jun 2026 19:36:32 -0700 [thread overview]
Message-ID: <6a35fcb0.6813c476.3c3d96.0003.GAE@google.com> (raw)
Hello,
syzbot found the following issue on:
HEAD commit: 5e2e14749c3d Merge tag 'landlock-7.2-rc1' of git://git.ker..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=10e5ccfe580000
kernel config: https://syzkaller.appspot.com/x/.config?x=b0ae27ce66b92956
dashboard link: https://syzkaller.appspot.com/bug?extid=395b7abe9696862fc188
compiler: Debian clang version 22.1.6 (++20260514074242+fc4aad7b5db3-1~exp1~20260514074407.73), Debian LLD 22.1.6
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/a565c60a4762/disk-5e2e1474.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/e593a6eb0057/vmlinux-5e2e1474.xz
kernel image: https://storage.googleapis.com/syzbot-assets/d24b55020ea3/bzImage-5e2e1474.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+395b7abe9696862fc188@syzkaller.appspotmail.com
==================================================================
BUG: KCSAN: data-race in __anon_vma_prepare / __vmf_anon_prepare
write to 0xffff88811a6a4d00 of 8 bytes by task 20911 on cpu 1:
__anon_vma_prepare+0x172/0x2f0 mm/rmap.c:212
__vmf_anon_prepare+0x91/0x100 mm/memory.c:3829
hugetlb_no_page+0x1b8/0xf30 mm/hugetlb.c:5756
hugetlb_fault+0x608/0xda0 mm/hugetlb.c:-1
handle_mm_fault+0x1de9/0x2da0 mm/memory.c:6684
faultin_page mm/gup.c:1126 [inline]
__get_user_pages+0x129c/0x1f10 mm/gup.c:1428
populate_vma_page_range mm/gup.c:1860 [inline]
__mm_populate+0x242/0x390 mm/gup.c:1963
mm_populate include/linux/mm.h:4171 [inline]
vm_mmap_pgoff+0x23b/0x2d0 mm/util.c:586
ksys_mmap_pgoff+0x2c6/0x310 mm/mmap.c:606
x64_sys_call+0x14df/0x3020 arch/x86/include/generated/asm/syscalls_64.h:10
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x136/0x3c0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
read to 0xffff88811a6a4d00 of 8 bytes by task 20901 on cpu 0:
__vmf_anon_prepare+0x26/0x100 mm/memory.c:3823
hugetlb_no_page+0x1b8/0xf30 mm/hugetlb.c:5756
hugetlb_fault+0x608/0xda0 mm/hugetlb.c:-1
handle_mm_fault+0x1de9/0x2da0 mm/memory.c:6684
do_user_addr_fault+0x402/0x1060 arch/x86/mm/fault.c:1394
handle_page_fault arch/x86/mm/fault.c:1483 [inline]
exc_page_fault+0x62/0xa0 arch/x86/mm/fault.c:1536
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595
__put_user_nocheck_4+0x3/0x20 arch/x86/lib/putuser.S:97
____sys_recvmsg+0x1a1/0x280 net/socket.c:2917
___sys_recvmsg+0x11f/0x3a0 net/socket.c:2946
do_recvmmsg+0x1e5/0x560 net/socket.c:3041
__sys_recvmmsg net/socket.c:3115 [inline]
__do_sys_recvmmsg net/socket.c:3138 [inline]
__se_sys_recvmmsg net/socket.c:3131 [inline]
__x64_sys_recvmmsg+0xe5/0x170 net/socket.c:3131
x64_sys_call+0x80f/0x3020 arch/x86/include/generated/asm/syscalls_64.h:300
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x136/0x3c0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
value changed: 0x0000000000000000 -> 0xffff8881020cec60
Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 20901 Comm: syz.0.4316 Tainted: G W syzkaller #0 PREEMPT(lazy)
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
==================================================================
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title
If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)
If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report
If you want to undo deduplication, reply with:
#syz undup
next reply other threads:[~2026-06-20 2:36 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-20 2:36 syzbot [this message]
2026-06-22 15:35 ` [syzbot] [mm?] KCSAN: data-race in __anon_vma_prepare / __vmf_anon_prepare (2) Lorenzo Stoakes
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=6a35fcb0.6813c476.3c3d96.0003.GAE@google.com \
--to=syzbot+395b7abe9696862fc188@syzkaller.appspotmail.com \
--cc=akpm@linux-foundation.org \
--cc=david@kernel.org \
--cc=harry@kernel.org \
--cc=jannh@google.com \
--cc=liam@infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=ljs@kernel.org \
--cc=riel@surriel.com \
--cc=syzkaller-bugs@googlegroups.com \
--cc=vbabka@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.