ethtool: Fix potential kernel buffer overflow in ETHTOOL_GRXCLSRLALL

On a 32-bit machine, info.rule_cnt >= 0x40000000 leads to integer
overflow and the buffer may be smaller than needed.  Since
ETHTOOL_GRXCLSRLALL is unprivileged, this can presumably be used for at
least denial of service.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Cc: stable@kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Ben Hutchings 2010-06-28 08:44:07 +00:00 committed by David S. Miller
parent c22d7ac844
commit db048b6903

View File

@ -347,8 +347,9 @@ static noinline_for_stack int ethtool_get_rxnfc(struct net_device *dev,
if (info.cmd == ETHTOOL_GRXCLSRLALL) {
if (info.rule_cnt > 0) {
rule_buf = kmalloc(info.rule_cnt * sizeof(u32),
GFP_USER);
if (info.rule_cnt <= KMALLOC_MAX_SIZE / sizeof(u32))
rule_buf = kmalloc(info.rule_cnt * sizeof(u32),
GFP_USER);
if (!rule_buf)
return -ENOMEM;
}