From: Johannes Berg johannes.berg@intel.com

stable inclusion from stable-v4.19.222 commit 03029bb044ccee60adbc93e70713f3ae58abc3a1 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IA6SIX CVE: CVE-2021-47611

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...

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commit 768c0b19b50665e337c96858aa2b7928d6dcf756 upstream.

Before attempting to parse an extended element, verify that the extended element ID is present.

Fixes: 41cbb0f5a295 ("mac80211: add support for HE") Reported-by: syzbot+59bdff68edce82e393b6@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/20211211201023.f30a1b128c07.I5cacc176da94ba316877c... Cc: stable@vger.kernel.org Signed-off-by: Johannes Berg johannes.berg@intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Hui Tang tanghui20@huawei.com --- net/mac80211/util.c | 2 ++ 1 file changed, 2 insertions(+)

diff --git a/net/mac80211/util.c b/net/mac80211/util.c index f101a6460b44..b8f43009409c 100644 --- a/net/mac80211/util.c +++ b/net/mac80211/util.c @@ -1096,6 +1096,8 @@ u32 ieee802_11_parse_elems_crc(const u8 *start, size_t len, bool action, elems->max_idle_period_ie = (void *)pos; break; case WLAN_EID_EXTENSION: + if (!elen) + break; if (pos[0] == WLAN_EID_EXT_HE_MU_EDCA && elen >= (sizeof(*elems->mu_edca_param_set) + 1)) { elems->mu_edca_param_set = (void *)&pos[1];