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authorJohannes Berg <johannes.berg@intel.com>2021-09-27 11:58:39 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2021-10-06 10:22:24 +0200
commit447d001b875d0e7f211c4ba004916028da994258 (patch)
tree8863f56a292be57d64b2c335b5f90834acf5a43f /net
parent7e71fcedfda6f7de18f850a6b36e78d78b04476f (diff)
mac80211: fix use-after-free in CCMP/GCMP RX
commit 94513069eb549737bcfc3d988d6ed4da948a2de8 upstream. When PN checking is done in mac80211, for fragmentation we need to copy the PN to the RX struct so we can later use it to do a comparison, since commit bf30ca922a0c ("mac80211: check defrag PN against current frame"). Unfortunately, in that commit I used the 'hdr' variable without it being necessarily valid, so use-after-free could occur if it was necessary to reallocate (parts of) the frame. Fix this by reloading the variable after the code that results in the reallocations, if any. This fixes https://bugzilla.kernel.org/show_bug.cgi?id=214401. Cc: stable@vger.kernel.org Fixes: bf30ca922a0c ("mac80211: check defrag PN against current frame") Link: https://lore.kernel.org/r/20210927115838.12b9ac6bb233.I1d066acd5408a662c3b6e828122cd314fcb28cdb@changeid Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net')
-rw-r--r--net/mac80211/wpa.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/net/mac80211/wpa.c b/net/mac80211/wpa.c
index 921115327ec8..3884bb1a59dd 100644
--- a/net/mac80211/wpa.c
+++ b/net/mac80211/wpa.c
@@ -519,6 +519,9 @@ ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data *rx,
return RX_DROP_UNUSABLE;
}
+ /* reload hdr - skb might have been reallocated */
+ hdr = (void *)rx->skb->data;
+
data_len = skb->len - hdrlen - IEEE80211_CCMP_HDR_LEN - mic_len;
if (!rx->sta || data_len < 0)
return RX_DROP_UNUSABLE;
@@ -751,6 +754,9 @@ ieee80211_crypto_gcmp_decrypt(struct ieee80211_rx_data *rx)
return RX_DROP_UNUSABLE;
}
+ /* reload hdr - skb might have been reallocated */
+ hdr = (void *)rx->skb->data;
+
data_len = skb->len - hdrlen - IEEE80211_GCMP_HDR_LEN - mic_len;
if (!rx->sta || data_len < 0)
return RX_DROP_UNUSABLE;