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authorJohannes Berg <johannes.berg@intel.com>2018-04-03 14:33:49 +0200
committerJohannes Berg <johannes.berg@intel.com>2018-04-19 15:46:34 +0200
commita7cfebcb7594a24609268f91299ab85ba064bf82 (patch)
tree0d478a1526a6954b58dc0e9204eaa40591eaffdb
parent911a26484c33e10de6237228ca1d7293548e9f49 (diff)
downloadop-kernel-dev-a7cfebcb7594a24609268f91299ab85ba064bf82.zip
op-kernel-dev-a7cfebcb7594a24609268f91299ab85ba064bf82.tar.gz
cfg80211: limit wiphy names to 128 bytes
There's currently no limit on wiphy names, other than netlink message size and memory limitations, but that causes issues when, for example, the wiphy name is used in a uevent, e.g. in rfkill where we use the same name for the rfkill instance, and then the buffer there is "only" 2k for the environment variables. This was reported by syzkaller, which used a 4k name. Limit the name to something reasonable, I randomly picked 128. Reported-by: syzbot+230d9e642a85d3fec29c@syzkaller.appspotmail.com Signed-off-by: Johannes Berg <johannes.berg@intel.com>
-rw-r--r--include/uapi/linux/nl80211.h2
-rw-r--r--net/wireless/core.c3
2 files changed, 5 insertions, 0 deletions
diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
index 15daf5e..9c36301 100644
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -2698,6 +2698,8 @@ enum nl80211_attrs {
#define NL80211_ATTR_KEYS NL80211_ATTR_KEYS
#define NL80211_ATTR_FEATURE_FLAGS NL80211_ATTR_FEATURE_FLAGS
+#define NL80211_WIPHY_NAME_MAXLEN 128
+
#define NL80211_MAX_SUPP_RATES 32
#define NL80211_MAX_SUPP_HT_RATES 77
#define NL80211_MAX_SUPP_REG_RULES 64
diff --git a/net/wireless/core.c b/net/wireless/core.c
index a6f3cac..c0fd8a8 100644
--- a/net/wireless/core.c
+++ b/net/wireless/core.c
@@ -95,6 +95,9 @@ static int cfg80211_dev_check_name(struct cfg80211_registered_device *rdev,
ASSERT_RTNL();
+ if (strlen(newname) > NL80211_WIPHY_NAME_MAXLEN)
+ return -EINVAL;
+
/* prohibit calling the thing phy%d when %d is not its number */
sscanf(newname, PHY_NAME "%d%n", &wiphy_idx, &taken);
if (taken == strlen(newname) && wiphy_idx != rdev->wiphy_idx) {
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