[PATCH] bna: integer overflow bug in debugfs
From: Dan Carpenter <hidden>
Date: 2017-03-17 20:52:35
Also in:
kernel-janitors
Subsystem:
brocade bna 10 gigabit ethernet driver, networking drivers, the rest · Maintainers:
Rasesh Mody, Sudarsana Kalluru, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
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 <redacted>
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;