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authorTuomas Tynkkynen <tuomas.tynkkynen@iki.fi>2020-04-10 15:32:57 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-04-21 09:05:00 +0200
commitcae385538886a353bd3429294ceca98dc969982d (patch)
tree701949334cf098c4556e7762e6b5c55e026de0fd
parenta8ce3412e8a22279e1bdc81c3c2bacd3785c1577 (diff)
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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/net/wireless/mac80211_hwsim.c12
1 files changed, 6 insertions, 6 deletions
diff --git a/drivers/net/wireless/mac80211_hwsim.c b/drivers/net/wireless/mac80211_hwsim.c
index 14f562cd715c..c48c68090d76 100644
--- a/drivers/net/wireless/mac80211_hwsim.c
+++ b/drivers/net/wireless/mac80211_hwsim.c
@@ -3575,9 +3575,9 @@ 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;
@@ -3597,9 +3597,9 @@ 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