From 608b0a2ae928a74a2f89e02227339dd79cdb63cf Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Mon, 31 May 2021 22:28:31 +0200 Subject: mac80211: check defrag PN against current frame commit bf30ca922a0c0176007e074b0acc77ed345e9990 upstream. As pointed out by Mathy Vanhoef, we implement the RX PN check on fragmented frames incorrectly - we check against the last received PN prior to the new frame, rather than to the one in this frame itself. Prior patches addressed the security issue here, but in order to be able to reason better about the code, fix it to really compare against the current frame's PN, not the last stored one. Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20210511200110.bfbc340ff071.Id0b690e581da7d03d76df90bb0e3fd55930bc8a0@changeid Signed-off-by: Johannes Berg Signed-off-by: Greg Kroah-Hartman --- include/linux/ieee80211.h | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'include') diff --git a/include/linux/ieee80211.h b/include/linux/ieee80211.h index e7a278ca1fde..a5bbec4c176f 100644 --- a/include/linux/ieee80211.h +++ b/include/linux/ieee80211.h @@ -638,6 +638,16 @@ static inline bool ieee80211_is_first_frag(__le16 seq_ctrl) return (seq_ctrl & cpu_to_le16(IEEE80211_SCTL_FRAG)) == 0; } +/** + * ieee80211_is_frag - check if a frame is a fragment + * @hdr: 802.11 header of the frame + */ +static inline bool ieee80211_is_frag(struct ieee80211_hdr *hdr) +{ + return ieee80211_has_morefrags(hdr->frame_control) || + hdr->seq_ctrl & cpu_to_le16(IEEE80211_SCTL_FRAG); +} + struct ieee80211s_hdr { u8 flags; u8 ttl; -- cgit v1.2.3