blob: a22395a70263bf7c291191178870d91235cfd050 [file] [log] [blame]
From 87e5cadb93bf57e5a7d0e9c80ecf7d03636a84f0 Mon Sep 17 00:00:00 2001
From: Tuomas Tynkkynen <tuomas.tynkkynen@iki.fi>
Date: Fri, 10 Apr 2020 15:32:57 +0300
Subject: [PATCH] mac80211_hwsim: Use kstrndup() in place of kasprintf()
commit 7ea862048317aa76d0f22334202779a25530980c upstream.
syzbot reports a warning:
precision 33020 too large
WARNING: CPU: 0 PID: 9618 at lib/vsprintf.c:2471 set_precision+0x150/0x180 lib/vsprintf.c:2471
vsnprintf+0xa7b/0x19a0 lib/vsprintf.c:2547
kvasprintf+0xb2/0x170 lib/kasprintf.c:22
kasprintf+0xbb/0xf0 lib/kasprintf.c:59
hwsim_del_radio_nl+0x63a/0x7e0 drivers/net/wireless/mac80211_hwsim.c:3625
genl_family_rcv_msg_doit net/netlink/genetlink.c:672 [inline]
...
entry_SYSCALL_64_after_hwframe+0x49/0xbe
Thus it seems that kasprintf() with "%.*s" format can not be used for
duplicating a string with arbitrary length. Replace it with kstrndup().
Note that later this string is limited to NL80211_WIPHY_NAME_MAXLEN == 64,
but the code is simpler this way.
Reported-by: syzbot+6693adf1698864d21734@syzkaller.appspotmail.com
Reported-by: syzbot+a4aee3f42d7584d76761@syzkaller.appspotmail.com
Cc: stable@kernel.org
Signed-off-by: Tuomas Tynkkynen <tuomas.tynkkynen@iki.fi>
Link: https://lore.kernel.org/r/20200410123257.14559-1-tuomas.tynkkynen@iki.fi
[johannes: add note about length limit]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
diff --git a/drivers/net/wireless/mac80211_hwsim.c b/drivers/net/wireless/mac80211_hwsim.c
index faec05ab4275..a87ab1f2153a 100644
--- a/drivers/net/wireless/mac80211_hwsim.c
+++ b/drivers/net/wireless/mac80211_hwsim.c
@@ -3476,9 +3476,9 @@ static int hwsim_new_radio_nl(struct sk_buff *msg, struct genl_info *info)
}
if (info->attrs[HWSIM_ATTR_RADIO_NAME]) {
- hwname = kasprintf(GFP_KERNEL, "%.*s",
- nla_len(info->attrs[HWSIM_ATTR_RADIO_NAME]),
- (char *)nla_data(info->attrs[HWSIM_ATTR_RADIO_NAME]));
+ hwname = kstrndup((char *)nla_data(info->attrs[HWSIM_ATTR_RADIO_NAME]),
+ nla_len(info->attrs[HWSIM_ATTR_RADIO_NAME]),
+ GFP_KERNEL);
if (!hwname)
return -ENOMEM;
param.hwname = hwname;
@@ -3498,9 +3498,9 @@ static int hwsim_del_radio_nl(struct sk_buff *msg, struct genl_info *info)
if (info->attrs[HWSIM_ATTR_RADIO_ID]) {
idx = nla_get_u32(info->attrs[HWSIM_ATTR_RADIO_ID]);
} else if (info->attrs[HWSIM_ATTR_RADIO_NAME]) {
- hwname = kasprintf(GFP_KERNEL, "%.*s",
- nla_len(info->attrs[HWSIM_ATTR_RADIO_NAME]),
- (char *)nla_data(info->attrs[HWSIM_ATTR_RADIO_NAME]));
+ hwname = kstrndup((char *)nla_data(info->attrs[HWSIM_ATTR_RADIO_NAME]),
+ nla_len(info->attrs[HWSIM_ATTR_RADIO_NAME]),
+ GFP_KERNEL);
if (!hwname)
return -ENOMEM;
} else
--
2.7.4