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authorJeff Layton <jlayton@redhat.com>2009-09-18 13:05:50 -0700
committerAl Viro <viro@zeniv.linux.org.uk>2009-09-24 07:47:31 -0400
commit5aa98b706e83da4cde4172c890d6e815915536a0 (patch)
treece7a52cb4d019110076ef0d3791a947ce343abc6 /fs/ioctl.c
parent05cc0cee6948fc11985d11557fb130645a7f69a6 (diff)
downloadlinux-5aa98b706e83da4cde4172c890d6e815915536a0.tar.gz
vfs: explicitly cast s_maxbytes in fiemap_check_ranges
If fiemap_check_ranges is passed a large enough value, then it's possible that the value would be cast to a signed value for comparison against s_maxbytes when we change it to loff_t. Make sure that doesn't happen by explicitly casting s_maxbytes to an unsigned value for the purposes of comparison. Signed-off-by: Jeff Layton <jlayton@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Robert Love <rlove@google.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mandeep Singh Baines <msb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/ioctl.c')
-rw-r--r--fs/ioctl.c9
1 files changed, 5 insertions, 4 deletions
diff --git a/fs/ioctl.c b/fs/ioctl.c
index 5612880fcbe..7b17a14396f 100644
--- a/fs/ioctl.c
+++ b/fs/ioctl.c
@@ -162,20 +162,21 @@ EXPORT_SYMBOL(fiemap_check_flags);
static int fiemap_check_ranges(struct super_block *sb,
u64 start, u64 len, u64 *new_len)
{
+ u64 maxbytes = (u64) sb->s_maxbytes;
+
*new_len = len;
if (len == 0)
return -EINVAL;
- if (start > sb->s_maxbytes)
+ if (start > maxbytes)
return -EFBIG;
/*
* Shrink request scope to what the fs can actually handle.
*/
- if ((len > sb->s_maxbytes) ||
- (sb->s_maxbytes - len) < start)
- *new_len = sb->s_maxbytes - start;
+ if (len > maxbytes || (maxbytes - len) < start)
+ *new_len = maxbytes - start;
return 0;
}