From: Ben Hutchings Date: Mon, 28 Jun 2010 08:44:07 +0000 (+0000) Subject: ethtool: Fix potential kernel buffer overflow in ETHTOOL_GRXCLSRLALL X-Git-Url: http://git.kernel.org/?p=linux%2Fkernel%2Fgit%2Fdavem%2Fnet-2.6.git;a=commitdiff_plain;h=db048b69037e7fa6a7d9e95a1271a50dc08ae233 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 Cc: stable@kernel.org Signed-off-by: David S. Miller --- diff --git a/net/core/ethtool.c b/net/core/ethtool.c index a0f4964..a3a7e9a 100644 --- a/net/core/ethtool.c +++ b/net/core/ethtool.c @@ -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; }