Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 5.17 620/772] wifi: mac80211: fix use-after-free in chanctx code | Date | Tue, 7 Jun 2022 19:03:32 +0200 |
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From: Johannes Berg <johannes.berg@intel.com>
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 <johannes.berg@intel.com> Signed-off-by: Kalle Valo <kvalo@kernel.org> Link: https://lore.kernel.org/r/20220601091926.df419d91b165.I17a9b3894ff0b8323ce2afdb153b101124c821e5@changeid Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- net/mac80211/chan.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-)
--- a/net/mac80211/chan.c +++ b/net/mac80211/chan.c @@ -1746,12 +1746,9 @@ int ieee80211_vif_use_reserved_context(s 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); } /*
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