[PATCH] sound/oss/emu10k1: handle userspace copy errors

Propagate copy_to/from_user() errors back through callers.

Signed-off-by: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 9 insertions, 4 deletions

diff --git a/sound/oss/emu10k1/passthrough.c b/sound/oss/emu10k1/passthrough.c
index 4e3baca7d41f..6d21d4368dec 100644
--- a/sound/oss/emu10k1/passthrough.c
+++ b/sound/oss/emu10k1/passthrough.c
@@ -162,12 +162,15 @@ ssize_t emu10k1_pt_write(struct file *file, const char __user *buffer, size_t co
 
                 DPD(3, "prepend size %d, prepending %d bytes\n", pt->prepend_size, needed);
                 if (count < needed) {
-                        copy_from_user(pt->buf + pt->prepend_size, buffer, count);
+                        if (copy_from_user(pt->buf + pt->prepend_size,
+                                           buffer, count))
+                                return -EFAULT;
                         pt->prepend_size += count;
                         DPD(3, "prepend size now %d\n", pt->prepend_size);
                         return count;
                 }
-                copy_from_user(pt->buf + pt->prepend_size, buffer, needed);
+                if (copy_from_user(pt->buf + pt->prepend_size, buffer, needed))
+                        return -EFAULT;
                 r = pt_putblock(wave_dev, (u16 *) pt->buf, nonblock);
                 if (r)
                         return r;
@@ -178,7 +181,8 @@ ssize_t emu10k1_pt_write(struct file *file, const char __user *buffer, size_t co
         blocks_copied = 0;
         while (blocks > 0) {
                 u16 __user *bufptr = (u16 __user *) buffer + (bytes_copied/2);
-                copy_from_user(pt->buf, bufptr, PT_BLOCKSIZE);
+                if (copy_from_user(pt->buf, bufptr, PT_BLOCKSIZE))
+                        return -EFAULT;
                 r = pt_putblock(wave_dev, (u16 *)pt->buf, nonblock);
                 if (r) {
                         if (bytes_copied)
@@ -193,7 +197,8 @@ ssize_t emu10k1_pt_write(struct file *file, const char __user *buffer, size_t co
         i = count - bytes_copied;
         if (i) {
                 pt->prepend_size = i;
-                copy_from_user(pt->buf, buffer + bytes_copied, i);
+                if (copy_from_user(pt->buf, buffer + bytes_copied, i))
+                        return -EFAULT;
                 bytes_copied += i;
                 DPD(3, "filling prepend buffer with %d bytes", i);
         }