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authorDylan Yudaken <dylany@fb.com>2022-07-14 04:02:57 -0700
committerJens Axboe <axboe@kernel.dk>2022-07-24 18:39:17 -0600
commit72c531f8ef3052c682d39dc21dcb5576afda208c (patch)
treefa5f25b57b6ac98b2af9048f4e604d6547d27f37 /net/compat.c
parent7fa875b8e53c288d616234b9daf417b0650ce1cc (diff)
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.c39
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;
}