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Subject[PATCH AUTOSEL for 4.4 09/59] bna: integer overflow bug in debugfs
Date
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>
---
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 8fc246ea1fb8..a4ad782007ce 100644
--- 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 *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;
--
2.11.0
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