4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Eric Biggers <ebiggers@xxxxxxxxxx>
commit 814596495dd2b9d4aab92d8f89cf19060d25d2ea upstream.
wiphy names were recently limited to 128 bytes by commit a7cfebcb7594
("cfg80211: limit wiphy names to 128 bytes"). As it turns out though,
this isn't sufficient because dev_vprintk_emit() needs the syslog header
string "SUBSYSTEM=ieee80211\0DEVICE=+ieee80211:$devname" to fit into 128
bytes. This triggered the "device/subsystem name too long" WARN when
the device name was >= 90 bytes. As before, this was reproduced by
syzbot by sending an HWSIM_CMD_NEW_RADIO command to the MAC80211_HWSIM
generic netlink family.
Fix it by further limiting wiphy names to 64 bytes.
Reported-by: syzbot+e64565577af34b3768dc@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: a7cfebcb7594 ("cfg80211: limit wiphy names to 128 bytes")
Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
include/uapi/linux/nl80211.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -2379,7 +2379,7 @@ 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_WIPHY_NAME_MAXLEN 64
#define NL80211_MAX_SUPP_RATES 32
#define NL80211_MAX_SUPP_HT_RATES 77
