[PATCH 5.16 226/285] io_uring: implement compat handling for IORING_REGISTER_IOWQ_AFF

Greg Kroah-Hartman
2022-04-12T08:25:56Z

From: Eugene Syromiatnikov <esyr@redhat.com>

commit 0f5e4b83b37a96e3643951588ed7176b9b187c0a upstream.

Similarly to the way it is done im mbind syscall.

Cc: stable@vger.kernel.org # 5.14
Fixes: fe76421d1da1dcdb ("io_uring: allow user configurable IO thread CPU affinity")
Signed-off-by: Eugene Syromiatnikov <esyr@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/io_uring.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)

--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -10799,7 +10799,15 @@ static __cold int io_register_iowq_aff(s
if (len > cpumask_size())
len = cpumask_size();

- if (copy_from_user(new_mask, arg, len)) {
+ if (in_compat_syscall()) {
+ ret = compat_get_bitmap(cpumask_bits(new_mask),
+ (const compat_ulong_t __user *)arg,
+ len * 8 /* CHAR_BIT */);
+ } else {
+ ret = copy_from_user(new_mask, arg, len);
+ }
+
+ if (ret) {
free_cpumask_var(new_mask);
return -EFAULT;
}