Messages in this thread Patch in this message | | | From | Kamal Mostafa <> | Subject | [PATCH 3.13.y-ckt 47/57] rds: fix an integer overflow test in rds_info_getsockopt() | Date | Tue, 22 Sep 2015 10:48:36 -0700 |
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3.13.11-ckt27 -stable review patch. If anyone has any objections, please let me know.
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From: Dan Carpenter <dan.carpenter@oracle.com>
commit 468b732b6f76b138c0926eadf38ac88467dcd271 upstream.
"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> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- net/rds/info.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/rds/info.c b/net/rds/info.c index 9a6b4f6..140a44a 100644 --- a/net/rds/info.c +++ b/net/rds/info.c @@ -176,7 +176,7 @@ int rds_info_getsockopt(struct socket *sock, int optname, char __user *optval, /* check for all kinds of wrapping and the like */ start = (unsigned long)optval; - if (len < 0 || len + PAGE_SIZE - 1 < len || start + len < start) { + if (len < 0 || len > INT_MAX - PAGE_SIZE + 1 || start + len < start) { ret = -EINVAL; goto out; } -- 1.9.1
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