ecryptfs fixes

memcpy() from userland pointer is a Bad Thing(tm)

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/fs/ecryptfs/miscdev.c b/fs/ecryptfs/miscdev.c
index 6560da1..50c994a 100644 (file)
--- a/fs/ecryptfs/miscdev.c
+++ b/fs/ecryptfs/miscdev.c
@@ -243,7 +243,6 @@ ecryptfs_miscdev_read(struct file *file, char __user *buf, size_t count,
        struct ecryptfs_daemon *daemon;
        struct ecryptfs_msg_ctx *msg_ctx;
        size_t packet_length_size;
-       u32 counter_nbo;
        char packet_length[3];
        size_t i;
        size_t total_length;
@@ -328,20 +327,18 @@ check_list:
                       "pending message\n", __func__, count, total_length);
                goto out_unlock_msg_ctx;
        }
-       i = 0;
-       buf[i++] = msg_ctx->type;
-       counter_nbo = cpu_to_be32(msg_ctx->counter);
-       memcpy(&buf[i], (char *)&counter_nbo, 4);
-       i += 4;
+       rc = -EFAULT;
+       if (put_user(msg_ctx->type, buf))
+               goto out_unlock_msg_ctx;
+       if (put_user(cpu_to_be32(msg_ctx->counter), (__be32 __user *)(buf + 1)))
+               goto out_unlock_msg_ctx;
+       i = 5;
        if (msg_ctx->msg) {
-               memcpy(&buf[i], packet_length, packet_length_size);
+               if (copy_to_user(&buf[i], packet_length, packet_length_size))
+                       goto out_unlock_msg_ctx;
                i += packet_length_size;
-               rc = copy_to_user(&buf[i], msg_ctx->msg, msg_ctx->msg_size);
-               if (rc) {
-                       printk(KERN_ERR "%s: copy_to_user returned error "
-                              "[%d]\n", __func__, rc);
+               if (copy_to_user(&buf[i], msg_ctx->msg, msg_ctx->msg_size))
                        goto out_unlock_msg_ctx;
-               }
                i += msg_ctx->msg_size;
        }
        rc = i;
@@ -452,7 +449,8 @@ static ssize_t
 ecryptfs_miscdev_write(struct file *file, const char __user *buf,
                       size_t count, loff_t *ppos)
 {
-       u32 counter_nbo, seq;
+       __be32 counter_nbo;
+       u32 seq;
        size_t packet_size, packet_size_length, i;
        ssize_t sz = 0;
        char *data;
@@ -485,7 +483,7 @@ ecryptfs_miscdev_write(struct file *file, const char __user *buf,
                               count);
                        goto out_free;
                }
-               memcpy((char *)&counter_nbo, &data[i], 4);
+               memcpy(&counter_nbo, &data[i], 4);
                seq = be32_to_cpu(counter_nbo);
                i += 4;
                rc = ecryptfs_parse_packet_length(&data[i], &packet_size,