diff options
| author | Tuomas Tynkkynen <tuomas.tynkkynen@iki.fi> | 2020-04-10 15:32:57 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-04-21 09:06:42 +0200 |
| commit | f6c13cca2ad06f18e83dd2e025d9266551fe5dd7 (patch) | |
| tree | 760a081f1dd7147c7519153f6b06df1705f911a7 | |
| parent | 0ad636958d7d8a70599cbc2fa02c98cc5546cd90 (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.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/drivers/net/wireless/mac80211_hwsim.c b/drivers/net/wireless/mac80211_hwsim.c index 03738107fd10..151752c00727 100644 --- a/drivers/net/wireless/mac80211_hwsim.c +++ b/drivers/net/wireless/mac80211_hwsim.c @@ -3600,9 +3600,9 @@ 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; @@ -3622,9 +3622,9 @@ 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 |