cfg80211: further limit wiphy names to 64 bytes

commit 814596495d upstream.

wiphy names were recently limited to 128 bytes by commit a7cfebcb75
("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@syzkaller.appspotmail.com
Fixes: a7cfebcb75 ("cfg80211: limit wiphy names to 128 bytes")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Eric Biggers 2018-05-14 20:09:24 -07:00 committed by Greg Kroah-Hartman
parent 9808c97d3c
commit bc342bc029

View file

@ -2604,7 +2604,7 @@ 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