From bd1cd32caa67e1af9acbf8889863bf0c6b1dca87 Mon Sep 17 00:00:00 2001 From: Colin Ian King Date: Mon, 12 Jul 2021 13:14:40 +0100 Subject: [PATCH] 6lowpan: iphc: Fix an off-by-one check of array index [ Upstream commit 9af417610b6142e826fd1ee8ba7ff3e9a2133a5a ] 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 Signed-off-by: Marcel Holtmann Signed-off-by: Sasha Levin --- net/6lowpan/debugfs.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) 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);