[PATCH] compat: fix uaccess handling

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 19 insertions, 16 deletions

diff --git a/fs/compat.c b/fs/compat.c
index 7aef5412f49c..a7e3f162fb15 100644
--- a/fs/compat.c
+++ b/fs/compat.c
@@ -1144,7 +1144,9 @@ asmlinkage long compat_sys_getdents64(unsigned int fd,
         lastdirent = buf.previous;
         if (lastdirent) {
                 typeof(lastdirent->d_off) d_off = file->f_pos;
-                __put_user_unaligned(d_off, &lastdirent->d_off);
+                error = -EFAULT;
+                if (__put_user_unaligned(d_off, &lastdirent->d_off))
+                        goto out_putf;
                 error = count - buf.count;
         }
 
@@ -1611,14 +1613,14 @@ int compat_get_fd_set(unsigned long nr, compat_ulong_t __user *ufdset,
                 nr &= ~1UL;
                 while (nr) {
                         unsigned long h, l;
-                        __get_user(l, ufdset);
-                        __get_user(h, ufdset+1);
+                        if (__get_user(l, ufdset) || __get_user(h, ufdset+1))
+                                return -EFAULT;
                         ufdset += 2;
                         *fdset++ = h << 32 | l;
                         nr -= 2;
                 }
-                if (odd)
-                        __get_user(*fdset, ufdset);
+                if (odd && __get_user(*fdset, ufdset))
+                        return -EFAULT;
         } else {
                 /* Tricky, must clear full unsigned long in the
                  * kernel fdset at the end, this makes sure that
@@ -1630,14 +1632,14 @@ int compat_get_fd_set(unsigned long nr, compat_ulong_t __user *ufdset,
 }
 
 static
-void compat_set_fd_set(unsigned long nr, compat_ulong_t __user *ufdset,
-                        unsigned long *fdset)
+int compat_set_fd_set(unsigned long nr, compat_ulong_t __user *ufdset,
+                      unsigned long *fdset)
 {
         unsigned long odd;
         nr = ROUND_UP(nr, __COMPAT_NFDBITS);
 
         if (!ufdset)
-                return;
+                return 0;
 
         odd = nr & 1UL;
         nr &= ~1UL;
@@ -1645,13 +1647,14 @@ void compat_set_fd_set(unsigned long nr, compat_ulong_t __user *ufdset,
                 unsigned long h, l;
                 l = *fdset++;
                 h = l >> 32;
-                __put_user(l, ufdset);
-                __put_user(h, ufdset+1);
+                if (__put_user(l, ufdset) || __put_user(h, ufdset+1))
+                        return -EFAULT;
                 ufdset += 2;
                 nr -= 2;
         }
-        if (odd)
-                __put_user(*fdset, ufdset);
+        if (odd && __put_user(*fdset, ufdset))
+                return -EFAULT;
+        return 0;
 }
 
 
@@ -1726,10 +1729,10 @@ int compat_core_sys_select(int n, compat_ulong_t __user *inp,
                 ret = 0;
         }
 
-        compat_set_fd_set(n, inp, fds.res_in);
-        compat_set_fd_set(n, outp, fds.res_out);
-        compat_set_fd_set(n, exp, fds.res_ex);
-
+        if (compat_set_fd_set(n, inp, fds.res_in) ||
+            compat_set_fd_set(n, outp, fds.res_out) ||
+            compat_set_fd_set(n, exp, fds.res_ex))
+                ret = -EFAULT;
 out:
         kfree(bits);
 out_nofds: