[moderation] [mm?] KCSAN: data-race in exec_mmap / vms_clear_ptes (4)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: d1d10cea0895 Merge tag 'perf-tools-fixes-for-v6.17-2025-09..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1709ba42580000
kernel config: https://syzkaller.appspot.com/x/.config?x=6e0c213d0735f5dd
dashboard link: https://syzkaller.appspot.com/bug?extid=60c113c7a4fe5249bffa
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
CC: [Liam.H...@oracle.com ak...@linux-foundation.org ja...@google.com linux-...@vger.kernel.org linu...@kvack.org lorenzo...@oracle.com pfal...@suse.de vba...@suse.cz]

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/f6a9e091ca95/disk-d1d10cea.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/409a7ddb2738/vmlinux-d1d10cea.xz
kernel image: https://storage.googleapis.com/syzbot-assets/2c6ea8e18797/bzImage-d1d10cea.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+60c113...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in exec_mmap / vms_clear_ptes

write to 0xffff888102715798 of 8 bytes by task 3294 on cpu 0:
update_hiwater_rss include/linux/mm.h:2657 [inline]
vms_clear_ptes+0x18f/0x2d0 mm/vma.c:1227
vms_complete_munmap_vmas+0x159/0x440 mm/vma.c:1277
do_vmi_align_munmap+0x383/0x3d0 mm/vma.c:1536
do_vmi_munmap+0x1db/0x220 mm/vma.c:1584
__vm_munmap+0x1a1/0x280 mm/vma.c:3155
__do_sys_munmap mm/mmap.c:1080 [inline]
__se_sys_munmap mm/mmap.c:1077 [inline]
__x64_sys_munmap+0x36/0x50 mm/mmap.c:1077
x64_sys_call+0x9c0/0x2ff0 arch/x86/include/generated/asm/syscalls_64.h:12
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888102715798 of 8 bytes by task 21747 on cpu 1:
get_mm_hiwater_rss include/linux/mm.h:2644 [inline]
setmax_mm_hiwater_rss include/linux/mm.h:2674 [inline]
exec_mmap+0x365/0x4d0 fs/exec.c:899
begin_new_exec+0xb6b/0x1160 fs/exec.c:1156
load_elf_binary+0x62b/0x1a20 fs/binfmt_elf.c:995
search_binary_handler fs/exec.c:1670 [inline]
exec_binprm fs/exec.c:1702 [inline]
bprm_execve+0x474/0x970 fs/exec.c:1754
do_execveat_common+0x6e6/0x750 fs/exec.c:1860
do_execve fs/exec.c:1934 [inline]
__do_sys_execve fs/exec.c:2010 [inline]
__se_sys_execve fs/exec.c:2005 [inline]
__x64_sys_execve+0x5c/0x70 fs/exec.c:2005
x64_sys_call+0x2716/0x2ff0 arch/x86/include/generated/asm/syscalls_64.h:60
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000000000002279 -> 0x0000000000002299

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 21747 Comm: syz-executor Tainted: G W syzkaller #0 PREEMPT(voluntary)
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
==================================================================


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