From 8565e483e3817823c754e15ada5c980faa9d17b7 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Tue, 27 Sep 2022 21:10:48 +0800 Subject: [PATCH] wifi: mac80211: fix use-after-free in chanctx code stable inclusion from stable-v5.10.121 commit 6118bbdf69f4718b02d26bbcf2e497eb66004331 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I5L6CQ Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=6118bbdf69f4718b02d26bbcf2e497eb66004331 -------------------------------- commit 2965c4cdf7ad9ce0796fac5e57debb9519ea721e upstream. In ieee80211_vif_use_reserved_context(), when we have an old context and the new context's replace_state is set to IEEE80211_CHANCTX_REPLACE_NONE, we free the old context in ieee80211_vif_use_reserved_reassign(). Therefore, we cannot check the old_ctx anymore, so we should set it to NULL after this point. However, since the new_ctx replace state is clearly not IEEE80211_CHANCTX_REPLACES_OTHER, we're not going to do anything else in this function and can just return to avoid accessing the freed old_ctx. Cc: stable@vger.kernel.org Fixes: 5bcae31d9cb1 ("mac80211: implement multi-vif in-place reservations") Signed-off-by: Johannes Berg Signed-off-by: Kalle Valo Link: https://lore.kernel.org/r/20220601091926.df419d91b165.I17a9b3894ff0b8323ce2afdb153b101124c821e5@changeid Signed-off-by: Greg Kroah-Hartman Signed-off-by: Zheng Zengkai Acked-by: Xie XiuQi --- net/mac80211/chan.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/net/mac80211/chan.c b/net/mac80211/chan.c index 8f48aff74c7b..5639a71257e4 100644 --- a/net/mac80211/chan.c +++ b/net/mac80211/chan.c @@ -1652,12 +1652,9 @@ int ieee80211_vif_use_reserved_context(struct ieee80211_sub_if_data *sdata) if (new_ctx->replace_state == IEEE80211_CHANCTX_REPLACE_NONE) { if (old_ctx) - err = ieee80211_vif_use_reserved_reassign(sdata); - else - err = ieee80211_vif_use_reserved_assign(sdata); + return ieee80211_vif_use_reserved_reassign(sdata); - if (err) - return err; + return ieee80211_vif_use_reserved_assign(sdata); } /* -- GitLab