fs: check for statfs overflow

Adds a check for an overflow in the filesystem size so if someone is
checking with statfs() on a 16G blocksize hugetlbfs in a 32bit binary that
it will report back EOVERFLOW instead of a size of 0.

Acked-by: Nishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: Jon Tollefson <kniht@linux.vnet.ibm.com>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 4 insertions, 4 deletions

diff --git a/fs/compat.c b/fs/compat.c
index ed43e17a5dc6..b46604281766 100644
--- a/fs/compat.c
+++ b/fs/compat.c
@@ -197,8 +197,8 @@ static int put_compat_statfs(struct compat_statfs __user *ubuf, struct kstatfs *
 {
         
         if (sizeof ubuf->f_blocks == 4) {
-                if ((kbuf->f_blocks | kbuf->f_bfree | kbuf->f_bavail) &
-                    0xffffffff00000000ULL)
+                if ((kbuf->f_blocks | kbuf->f_bfree | kbuf->f_bavail |
+                     kbuf->f_bsize | kbuf->f_frsize) & 0xffffffff00000000ULL)
                         return -EOVERFLOW;
                 /* f_files and f_ffree may be -1; it's okay
                  * to stuff that into 32 bits */
@@ -271,8 +271,8 @@ out:
 static int put_compat_statfs64(struct compat_statfs64 __user *ubuf, struct kstatfs *kbuf)
 {
         if (sizeof ubuf->f_blocks == 4) {
-                if ((kbuf->f_blocks | kbuf->f_bfree | kbuf->f_bavail) &
-                    0xffffffff00000000ULL)
+                if ((kbuf->f_blocks | kbuf->f_bfree | kbuf->f_bavail |
+                     kbuf->f_bsize | kbuf->f_frsize) & 0xffffffff00000000ULL)
                         return -EOVERFLOW;
                 /* f_files and f_ffree may be -1; it's okay
                  * to stuff that into 32 bits */