Commit 5aa98b70 authored by Jeff Layton's avatar Jeff Layton Committed by Al Viro

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: default avatarJeff 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: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 05cc0cee
...@@ -162,20 +162,21 @@ EXPORT_SYMBOL(fiemap_check_flags); ...@@ -162,20 +162,21 @@ EXPORT_SYMBOL(fiemap_check_flags);
static int fiemap_check_ranges(struct super_block *sb, static int fiemap_check_ranges(struct super_block *sb,
u64 start, u64 len, u64 *new_len) u64 start, u64 len, u64 *new_len)
{ {
u64 maxbytes = (u64) sb->s_maxbytes;
*new_len = len; *new_len = len;
if (len == 0) if (len == 0)
return -EINVAL; return -EINVAL;
if (start > sb->s_maxbytes) if (start > maxbytes)
return -EFBIG; return -EFBIG;
/* /*
* Shrink request scope to what the fs can actually handle. * Shrink request scope to what the fs can actually handle.
*/ */
if ((len > sb->s_maxbytes) || if (len > maxbytes || (maxbytes - len) < start)
(sb->s_maxbytes - len) < start) *new_len = maxbytes - start;
*new_len = sb->s_maxbytes - start;
return 0; return 0;
} }
......
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