diff options
Diffstat (limited to 'package/kernel/mac80211/patches/subsys/355-wifi-cfg80211-fix-BSS-refcounting-bugs.patch')
| -rw-r--r-- | package/kernel/mac80211/patches/subsys/355-wifi-cfg80211-fix-BSS-refcounting-bugs.patch | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/package/kernel/mac80211/patches/subsys/355-wifi-cfg80211-fix-BSS-refcounting-bugs.patch b/package/kernel/mac80211/patches/subsys/355-wifi-cfg80211-fix-BSS-refcounting-bugs.patch new file mode 100644 index 0000000000..4680e1e815 --- /dev/null +++ b/package/kernel/mac80211/patches/subsys/355-wifi-cfg80211-fix-BSS-refcounting-bugs.patch @@ -0,0 +1,87 @@ +From: Johannes Berg <johannes.berg@intel.com> +Date: Fri, 30 Sep 2022 23:44:23 +0200 +Subject: [PATCH] wifi: cfg80211: fix BSS refcounting bugs +MIME-Version: 1.0 +Content-Type: text/plain; charset=UTF-8 +Content-Transfer-Encoding: 8bit + +commit 0b7808818cb9df6680f98996b8e9a439fa7bcc2f upstream. + +There are multiple refcounting bugs related to multi-BSSID: + - In bss_ref_get(), if the BSS has a hidden_beacon_bss, then + the bss pointer is overwritten before checking for the + transmitted BSS, which is clearly wrong. Fix this by using + the bss_from_pub() macro. + + - In cfg80211_bss_update() we copy the transmitted_bss pointer + from tmp into new, but then if we release new, we'll unref + it erroneously. We already set the pointer and ref it, but + need to NULL it since it was copied from the tmp data. + + - In cfg80211_inform_single_bss_data(), if adding to the non- + transmitted list fails, we unlink the BSS and yet still we + return it, but this results in returning an entry without + a reference. We shouldn't return it anyway if it was broken + enough to not get added there. + +This fixes CVE-2022-42720. + +Reported-by: Sönke Huster <shuster@seemoo.tu-darmstadt.de> +Tested-by: Sönke Huster <shuster@seemoo.tu-darmstadt.de> +Fixes: a3584f56de1c ("cfg80211: Properly track transmitting and non-transmitting BSS") +Signed-off-by: Johannes Berg <johannes.berg@intel.com> +--- + +--- a/net/wireless/scan.c ++++ b/net/wireless/scan.c +@@ -143,18 +143,12 @@ static inline void bss_ref_get(struct cf + lockdep_assert_held(&rdev->bss_lock); + + bss->refcount++; +- if (bss->pub.hidden_beacon_bss) { +- bss = container_of(bss->pub.hidden_beacon_bss, +- struct cfg80211_internal_bss, +- pub); +- bss->refcount++; +- } +- if (bss->pub.transmitted_bss) { +- bss = container_of(bss->pub.transmitted_bss, +- struct cfg80211_internal_bss, +- pub); +- bss->refcount++; +- } ++ ++ if (bss->pub.hidden_beacon_bss) ++ bss_from_pub(bss->pub.hidden_beacon_bss)->refcount++; ++ ++ if (bss->pub.transmitted_bss) ++ bss_from_pub(bss->pub.transmitted_bss)->refcount++; + } + + static inline void bss_ref_put(struct cfg80211_registered_device *rdev, +@@ -1743,6 +1737,8 @@ cfg80211_bss_update(struct cfg80211_regi + new->refcount = 1; + INIT_LIST_HEAD(&new->hidden_list); + INIT_LIST_HEAD(&new->pub.nontrans_list); ++ /* we'll set this later if it was non-NULL */ ++ new->pub.transmitted_bss = NULL; + + if (rcu_access_pointer(tmp->pub.proberesp_ies)) { + hidden = rb_find_bss(rdev, tmp, BSS_CMP_HIDE_ZLEN); +@@ -1983,10 +1979,15 @@ cfg80211_inform_single_bss_data(struct w + spin_lock_bh(&rdev->bss_lock); + if (cfg80211_add_nontrans_list(non_tx_data->tx_bss, + &res->pub)) { +- if (__cfg80211_unlink_bss(rdev, res)) ++ if (__cfg80211_unlink_bss(rdev, res)) { + rdev->bss_generation++; ++ res = NULL; ++ } + } + spin_unlock_bh(&rdev->bss_lock); ++ ++ if (!res) ++ return NULL; + } + + trace_cfg80211_return_bss(&res->pub); |