From 13e2d5187f6b965ba3556caedb914baf81b98ed2 Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Fri, 17 Mar 2017 23:52:35 +0300 Subject: [PATCH] bna: integer overflow bug in debugfs 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 Acked-by: Rasesh Mody Signed-off-by: David S. Miller --- drivers/net/ethernet/brocade/bna/bnad_debugfs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/ethernet/brocade/bna/bnad_debugfs.c b/drivers/net/ethernet/brocade/bna/bnad_debugfs.c index 05c1c1dd7751..cebfe3bd086e 100644 --- a/drivers/net/ethernet/brocade/bna/bnad_debugfs.c +++ b/drivers/net/ethernet/brocade/bna/bnad_debugfs.c @@ -325,7 +325,7 @@ bnad_debugfs_write_regrd(struct file *file, const char __user *buf, 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;