From 5aa98b706e83da4cde4172c890d6e815915536a0 Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Fri, 18 Sep 2009 13:05:50 -0700 Subject: [PATCH] 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 Cc: Christoph Hellwig Cc: Robert Love Cc: Al Viro Cc: Johannes Weiner Cc: Mandeep Singh Baines Signed-off-by: Andrew Morton Signed-off-by: Al Viro --- fs/ioctl.c | 9 +++++---- 1 file 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; }