From: Johannes Berg <johannes.berg@intel.com> stable inclusion from stable-5.10.77 commit fa29cec42c2d306cae0d5dbe0d92f0185253e8dc bugzilla: 185677 https://gitee.com/openeuler/kernel/issues/I4IAP7 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- commit a2083eeb119fb9307258baea9b7c243ca9a2e0b6 upstream. The SSID pointer is pointing to RCU protected data, so we need to have it under rcu_read_lock() for the entire use. Fix this. Cc: stable@vger.kernel.org Fixes: 0b8fb8235be8 ("cfg80211: Parsing of Multiple BSSID information in scanning") Link: https://lore.kernel.org/r/20210930131120.6ddfc603aa1d.I2137344c4e2426525b1a8... Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Chen Jun <chenjun102@huawei.com> Acked-by: Weilong Chen <chenweilong@huawei.com> Signed-off-by: Chen Jun <chenjun102@huawei.com> --- net/wireless/scan.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/net/wireless/scan.c b/net/wireless/scan.c index fab1f0d50403..fd614a5a00b4 100644 --- a/net/wireless/scan.c +++ b/net/wireless/scan.c @@ -418,14 +418,17 @@ cfg80211_add_nontrans_list(struct cfg80211_bss *trans_bss, } ssid_len = ssid[1]; ssid = ssid + 2; - rcu_read_unlock(); /* check if nontrans_bss is in the list */ list_for_each_entry(bss, &trans_bss->nontrans_list, nontrans_list) { - if (is_bss(bss, nontrans_bss->bssid, ssid, ssid_len)) + if (is_bss(bss, nontrans_bss->bssid, ssid, ssid_len)) { + rcu_read_unlock(); return 0; + } } + rcu_read_unlock(); + /* add to the list */ list_add_tail(&nontrans_bss->nontrans_list, &trans_bss->nontrans_list); return 0; -- 2.20.1