[moderation] [mm?] KCSAN: data-race in _copy_from_iter / _copy_from_iter (3)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: e67572cd2204 Linux 6.9-rc6
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=16b57af8980000
kernel config: https://syzkaller.appspot.com/x/.config?x=c3beef2aff822313
dashboard link: https://syzkaller.appspot.com/bug?extid=4327174be96f5f7e66f9
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/7b20866b5f53/disk-e67572cd.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/4c1441ce05e8/vmlinux-e67572cd.xz
kernel image: https://storage.googleapis.com/syzbot-assets/382a9e170b40/bzImage-e67572cd.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+432717...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in _copy_from_iter / _copy_from_iter

write to 0xffff88810d203000 of 4096 bytes by task 22265 on cpu 0:
instrument_copy_from_user_before include/linux/instrumented.h:130 [inline]
copy_from_user_iter lib/iov_iter.c:54 [inline]
iterate_ubuf include/linux/iov_iter.h:29 [inline]
iterate_and_advance2 include/linux/iov_iter.h:245 [inline]
iterate_and_advance include/linux/iov_iter.h:271 [inline]
__copy_from_iter lib/iov_iter.c:249 [inline]
_copy_from_iter+0x129/0xb00 lib/iov_iter.c:260
copy_page_from_iter+0x14f/0x280 lib/iov_iter.c:422
process_vm_rw_pages mm/process_vm_access.c:43 [inline]
process_vm_rw_single_vec mm/process_vm_access.c:118 [inline]
process_vm_rw_core mm/process_vm_access.c:216 [inline]
process_vm_rw+0x5d6/0x8c0 mm/process_vm_access.c:284
__do_sys_process_vm_writev mm/process_vm_access.c:304 [inline]
__se_sys_process_vm_writev mm/process_vm_access.c:299 [inline]
__x64_sys_process_vm_writev+0x7a/0x90 mm/process_vm_access.c:299
x64_sys_call+0x2ae1/0x2d30 arch/x86/include/generated/asm/syscalls_64.h:312
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+0x77/0x7f

write to 0xffff88810d203000 of 4096 bytes by task 22267 on cpu 1:
instrument_copy_from_user_before include/linux/instrumented.h:130 [inline]
copy_from_user_iter lib/iov_iter.c:54 [inline]
iterate_ubuf include/linux/iov_iter.h:29 [inline]
iterate_and_advance2 include/linux/iov_iter.h:245 [inline]
iterate_and_advance include/linux/iov_iter.h:271 [inline]
__copy_from_iter lib/iov_iter.c:249 [inline]
_copy_from_iter+0x129/0xb00 lib/iov_iter.c:260
copy_page_from_iter+0x14f/0x280 lib/iov_iter.c:422
process_vm_rw_pages mm/process_vm_access.c:43 [inline]
process_vm_rw_single_vec mm/process_vm_access.c:118 [inline]
process_vm_rw_core mm/process_vm_access.c:216 [inline]
process_vm_rw+0x5d6/0x8c0 mm/process_vm_access.c:284
__do_sys_process_vm_writev mm/process_vm_access.c:304 [inline]
__se_sys_process_vm_writev mm/process_vm_access.c:299 [inline]
__x64_sys_process_vm_writev+0x7a/0x90 mm/process_vm_access.c:299
x64_sys_call+0x2ae1/0x2d30 arch/x86/include/generated/asm/syscalls_64.h:312
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+0x77/0x7f

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 22267 Comm: syz-executor.1 Tainted: G W 6.9.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
==================================================================


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