diff options
| author | Dylan Yudaken <dylany@fb.com> | 2022-07-14 04:02:57 -0700 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2022-07-24 18:39:17 -0600 |
| commit | 72c531f8ef3052c682d39dc21dcb5576afda208c (patch) | |
| tree | fa5f25b57b6ac98b2af9048f4e604d6547d27f37 /net/compat.c | |
| parent | 7fa875b8e53c288d616234b9daf417b0650ce1cc (diff) | |
| download | lwn-72c531f8ef3052c682d39dc21dcb5576afda208c.tar.gz lwn-72c531f8ef3052c682d39dc21dcb5576afda208c.zip | |
net: copy from user before calling __get_compat_msghdr
this is in preparation for multishot receive from io_uring, where it needs
to have access to the original struct user_msghdr.
functionally this should be a no-op.
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Dylan Yudaken <dylany@fb.com>
Link: https://lore.kernel.org/r/20220714110258.1336200-3-dylany@fb.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'net/compat.c')
| -rw-r--r-- | net/compat.c | 39 |
1 files changed, 17 insertions, 22 deletions
diff --git a/net/compat.c b/net/compat.c index 210fc3b4d0d8..513aa9a3fc64 100644 --- a/net/compat.c +++ b/net/compat.c @@ -34,20 +34,15 @@ #include <net/compat.h> int __get_compat_msghdr(struct msghdr *kmsg, - struct compat_msghdr __user *umsg, - struct sockaddr __user **save_addr, - compat_uptr_t *ptr, compat_size_t *len) + struct compat_msghdr *msg, + struct sockaddr __user **save_addr) { - struct compat_msghdr msg; ssize_t err; - if (copy_from_user(&msg, umsg, sizeof(*umsg))) - return -EFAULT; - - kmsg->msg_flags = msg.msg_flags; - kmsg->msg_namelen = msg.msg_namelen; + kmsg->msg_flags = msg->msg_flags; + kmsg->msg_namelen = msg->msg_namelen; - if (!msg.msg_name) + if (!msg->msg_name) kmsg->msg_namelen = 0; if (kmsg->msg_namelen < 0) @@ -57,15 +52,15 @@ int __get_compat_msghdr(struct msghdr *kmsg, kmsg->msg_namelen = sizeof(struct sockaddr_storage); kmsg->msg_control_is_user = true; - kmsg->msg_control_user = compat_ptr(msg.msg_control); - kmsg->msg_controllen = msg.msg_controllen; + kmsg->msg_control_user = compat_ptr(msg->msg_control); + kmsg->msg_controllen = msg->msg_controllen; if (save_addr) - *save_addr = compat_ptr(msg.msg_name); + *save_addr = compat_ptr(msg->msg_name); - if (msg.msg_name && kmsg->msg_namelen) { + if (msg->msg_name && kmsg->msg_namelen) { if (!save_addr) { - err = move_addr_to_kernel(compat_ptr(msg.msg_name), + err = move_addr_to_kernel(compat_ptr(msg->msg_name), kmsg->msg_namelen, kmsg->msg_name); if (err < 0) @@ -76,12 +71,10 @@ int __get_compat_msghdr(struct msghdr *kmsg, kmsg->msg_namelen = 0; } - if (msg.msg_iovlen > UIO_MAXIOV) + if (msg->msg_iovlen > UIO_MAXIOV) return -EMSGSIZE; kmsg->msg_iocb = NULL; - *ptr = msg.msg_iov; - *len = msg.msg_iovlen; return 0; } @@ -90,15 +83,17 @@ int get_compat_msghdr(struct msghdr *kmsg, struct sockaddr __user **save_addr, struct iovec **iov) { - compat_uptr_t ptr; - compat_size_t len; + struct compat_msghdr msg; ssize_t err; - err = __get_compat_msghdr(kmsg, umsg, save_addr, &ptr, &len); + if (copy_from_user(&msg, umsg, sizeof(*umsg))) + return -EFAULT; + + err = __get_compat_msghdr(kmsg, umsg, save_addr); if (err) return err; - err = import_iovec(save_addr ? READ : WRITE, compat_ptr(ptr), len, + err = import_iovec(save_addr ? READ : WRITE, compat_ptr(msg.msg_iov), msg.msg_iovlen, UIO_FASTIOV, iov, &kmsg->msg_iter); return err < 0 ? err : 0; } |