i2o: check return code from put_user()

Check return value of put_user() and return -EFAULT if it failed.
Original comment "We did a get user...so assuming mem is ok...is this
bad?" is incorrect because memory can be read only.

Signed-off-by: Kulikov Vasiliy <segooon@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 9 insertions, 7 deletions

diff --git a/drivers/message/i2o/i2o_config.c b/drivers/message/i2o/i2o_config.c
index 4dd39a03082..068ba0785bb 100644
--- a/drivers/message/i2o/i2o_config.c
+++ b/drivers/message/i2o/i2o_config.c
@@ -111,9 +111,9 @@ static int i2o_cfg_gethrt(unsigned long arg)
 
         len = 8 + ((hrt->entry_len * hrt->num_entries) << 2);
 
-        /* We did a get user...so assuming mem is ok...is this bad? */
-        put_user(len, kcmd.reslen);
-        if (len > reslen)
+        if (put_user(len, kcmd.reslen))
+                ret = -EFAULT;
+        else if (len > reslen)
                 ret = -ENOBUFS;
         else if (copy_to_user(kcmd.resbuf, (void *)hrt, len))
                 ret = -EFAULT;
@@ -147,8 +147,9 @@ static int i2o_cfg_getlct(unsigned long arg)
         lct = (i2o_lct *) c->lct;
 
         len = (unsigned int)lct->table_size << 2;
-        put_user(len, kcmd.reslen);
-        if (len > reslen)
+        if (put_user(len, kcmd.reslen))
+                ret = -EFAULT;
+        else if (len > reslen)
                 ret = -ENOBUFS;
         else if (copy_to_user(kcmd.resbuf, lct, len))
                 ret = -EFAULT;
@@ -208,8 +209,9 @@ static int i2o_cfg_parms(unsigned long arg, unsigned int type)
                 return -EAGAIN;
         }
 
-        put_user(len, kcmd.reslen);
-        if (len > reslen)
+        if (put_user(len, kcmd.reslen))
+                ret = -EFAULT;
+        else if (len > reslen)
                 ret = -ENOBUFS;
         else if (copy_to_user(kcmd.resbuf, res, len))
                 ret = -EFAULT;