[moderation] [mm?] KCSAN: data-race in exec_mmap / unmap_region (6)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: a5b6244cf87c Merge tag 'block-6.8-2024-02-10' of git://git..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=170ecd20180000
kernel config: https://syzkaller.appspot.com/x/.config?x=3cd0dc1b46a5bc5c
dashboard link: https://syzkaller.appspot.com/bug?extid=715f89eac10cebda32df
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
CC: [ak...@linux-foundation.org linux-...@vger.kernel.org linu...@kvack.org]

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/c1a21353ecf6/disk-a5b6244c.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/675fe8a43c32/vmlinux-a5b6244c.xz
kernel image: https://storage.googleapis.com/syzbot-assets/1848dc711f3f/bzImage-a5b6244c.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+715f89...@syzkaller.appspotmail.com

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

write to 0xffff888102cceaf0 of 8 bytes by task 2811 on cpu 0:
update_hiwater_rss include/linux/mm.h:2635 [inline]
unmap_region+0x105/0x230 mm/mmap.c:2305
do_vmi_align_munmap+0x650/0x9c0 mm/mmap.c:2627
do_vmi_munmap+0x1ea/0x230 mm/mmap.c:2695
__vm_munmap+0xe6/0x1d0 mm/mmap.c:2982
__do_sys_munmap mm/mmap.c:2999 [inline]
__se_sys_munmap mm/mmap.c:2996 [inline]
__x64_sys_munmap+0x36/0x40 mm/mmap.c:2996
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x1d0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b

read to 0xffff888102cceaf0 of 8 bytes by task 19120 on cpu 1:
get_mm_hiwater_rss include/linux/mm.h:2622 [inline]
setmax_mm_hiwater_rss include/linux/mm.h:2652 [inline]
exec_mmap+0x2b7/0x430 fs/exec.c:1049
begin_new_exec+0xab7/0xfa0 fs/exec.c:1310
load_elf_binary+0x63d/0x1800 fs/binfmt_elf.c:996
search_binary_handler fs/exec.c:1783 [inline]
exec_binprm fs/exec.c:1825 [inline]
bprm_execve+0x4e2/0xc50 fs/exec.c:1877
do_execveat_common+0x760/0x7d0 fs/exec.c:1984
do_execve fs/exec.c:2058 [inline]
__do_sys_execve fs/exec.c:2134 [inline]
__se_sys_execve fs/exec.c:2129 [inline]
__x64_sys_execve+0x5a/0x70 fs/exec.c:2129
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x1d0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b

value changed: 0x0000000000000227 -> 0x0000000000000247

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 19120 Comm: dhcpcd Not tainted 6.8.0-rc3-syzkaller-00293-ga5b6244cf87c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
==================================================================


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.