4.4-stable review patch. If anyone has any objections, please let me know.
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From: Dan Carpenter dan.carpenter@oracle.com
[ Upstream commit 13e2d5187f6b965ba3556caedb914baf81b98ed2 ]
We could allocate less memory than intended because we do:
bnad->regdata = kzalloc(len << 2, GFP_KERNEL);
The shift can overflow leading to a crash. This is debugfs code so the impact is very small.
Fixes: 7afc5dbde091 ("bna: Add debugfs interface.") Signed-off-by: Dan Carpenter dan.carpenter@oracle.com Acked-by: Rasesh Mody rasesh.mody@cavium.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin alexander.levin@verizon.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/ethernet/brocade/bna/bnad_debugfs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/net/ethernet/brocade/bna/bnad_debugfs.c +++ b/drivers/net/ethernet/brocade/bna/bnad_debugfs.c @@ -324,7 +324,7 @@ bnad_debugfs_write_regrd(struct file *fi return PTR_ERR(kern_buf);
rc = sscanf(kern_buf, "%x:%x", &addr, &len); - if (rc < 2) { + if (rc < 2 || len > UINT_MAX >> 2) { netdev_warn(bnad->netdev, "failed to read user buffer\n"); kfree(kern_buf); return -EINVAL;