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| author | Jeff Layton <jlayton@redhat.com> | 2009-09-18 13:05:50 -0700 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2009-09-24 07:47:31 -0400 |
| commit | 5aa98b706e83da4cde4172c890d6e815915536a0 (patch) | |
| tree | ce7a52cb4d019110076ef0d3791a947ce343abc6 /fs/ioctl.c | |
| parent | 05cc0cee6948fc11985d11557fb130645a7f69a6 (diff) | |
| download | lwn-5aa98b706e83da4cde4172c890d6e815915536a0.tar.gz lwn-5aa98b706e83da4cde4172c890d6e815915536a0.zip | |
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.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/fs/ioctl.c b/fs/ioctl.c index 5612880fcbe7..7b17a14396ff 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; } |