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authorJohannes Berg <johannes.berg@intel.com>2021-09-27 11:58:39 +0200
committerJohannes Berg <johannes.berg@intel.com>2021-09-27 11:59:49 +0200
commit94513069eb549737bcfc3d988d6ed4da948a2de8 (patch)
treea5ddc800d86b21eb398056f8d287ed7e238769ad /net
parent313bbd1990b6ddfdaa7da098d0c56b098a833572 (diff)
mac80211: fix use-after-free in CCMP/GCMP RX
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>
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 bca47fad5a16..4eed23e27610 100644
--- a/net/mac80211/wpa.c
+++ b/net/mac80211/wpa.c
@@ -520,6 +520,9 @@ 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;
@@ -749,6 +752,9 @@ 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;