rds: fix an integer overflow test in rds_info_getsockopt()
authorDan Carpenter <dan.carpenter@oracle.com>
Sat, 1 Aug 2015 12:33:26 +0000 (15:33 +0300)
committerDavid S. Miller <davem@davemloft.net>
Mon, 3 Aug 2015 22:20:16 +0000 (15:20 -0700)
commit468b732b6f76b138c0926eadf38ac88467dcd271
tree73a2bc14e65b87701954fbc997c62b54ba8ae52f
parent636dba8e12d797357b2063981476390f11262c08
rds: fix an integer overflow test in rds_info_getsockopt()

"len" is a signed integer.  We check that len is not negative, so it
goes from zero to INT_MAX.  PAGE_SIZE is unsigned long so the comparison
is type promoted to unsigned long.  ULONG_MAX - 4095 is a higher than
INT_MAX so the condition can never be true.

I don't know if this is harmful but it seems safe to limit "len" to
INT_MAX - 4095.

Fixes: a8c879a7ee98 ('RDS: Info and stats')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/rds/info.c