diff mbox series

6lowpan: iphc: Fix an off-by-one check of array index

Message ID 20210712121440.17860-1-colin.king@canonical.com
State New
Headers show
Series 6lowpan: iphc: Fix an off-by-one check of array index | expand

Commit Message

Colin King July 12, 2021, 12:14 p.m. UTC 
From: Colin Ian King <colin.king@canonical.com>

The bounds check of id is off-by-one and the comparison should
be >= rather >. Currently the WARN_ON_ONCE check does not stop
the out of range indexing of &ldev->ctx.table[id] so also add
a return path if the bounds are out of range.

Addresses-Coverity: ("Illegal address computation").
Fixes: 5609c185f24d ("6lowpan: iphc: add support for stateful compression")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
 net/6lowpan/debugfs.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Comments

Marcel Holtmann July 22, 2021, 2:19 p.m. UTC | #1 
Hi Colin,

> The bounds check of id is off-by-one and the comparison should
> be >= rather >. Currently the WARN_ON_ONCE check does not stop
> the out of range indexing of &ldev->ctx.table[id] so also add
> a return path if the bounds are out of range.
> 
> Addresses-Coverity: ("Illegal address computation").
> Fixes: 5609c185f24d ("6lowpan: iphc: add support for stateful compression")
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
> ---
> net/6lowpan/debugfs.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)

patch has been applied to bluetooth-next tree.

Regards

Marcel
diff mbox series

Patch

diff --git a/net/6lowpan/debugfs.c b/net/6lowpan/debugfs.c
index 1c140af06d52..600b9563bfc5 100644
--- a/net/6lowpan/debugfs.c
+++ b/net/6lowpan/debugfs.c
@@ -170,7 +170,8 @@  static void lowpan_dev_debugfs_ctx_init(struct net_device *dev,
 	struct dentry *root;
 	char buf[32];
 
-	WARN_ON_ONCE(id > LOWPAN_IPHC_CTX_TABLE_SIZE);
+	if (WARN_ON_ONCE(id >= LOWPAN_IPHC_CTX_TABLE_SIZE))
+		return;
 
 	sprintf(buf, "%d", id);