[PATCH] fs: check for statfs overflow

From: Jon Tollefson
Date: Thu Jul 24 2008 - 00:27:55 EST


[ Upstream commit f4a67cceee4a6f5ed38011a698c9e34747270ae5 ]

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@xxxxxxxxxx>
Signed-off-by: Jon Tollefson <kniht@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Nick Piggin <npiggin@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
CC: Oliver Pinter <oliver.pntr@xxxxxxxxx>

diff --git a/fs/compat.c b/fs/compat.c
index ed43e17..b466042 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 */
diff --git a/fs/open.c b/fs/open.c
index a99ad09..bb98d2f 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -64,7 +64,8 @@ static int vfs_statfs_native(struct dentry *dentry, struct statfs *buf)
memcpy(buf, &st, sizeof(st));
else {
if (sizeof buf->f_blocks == 4) {
- if ((st.f_blocks | st.f_bfree | st.f_bavail) &
+ if ((st.f_blocks | st.f_bfree | st.f_bavail |
+ st.f_bsize | st.f_frsize) &
0xffffffff00000000ULL)
return -EOVERFLOW;
/*
--
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