wifi: mac80211: avoid trimming injected FCS twice

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When packet sockets use PACKET_QDISC_BYPASS, mac80211 can parse the
radiotap header while selecting the queue and again before transmit.

If the header includes an FCS, both parses trim the skb. Validate the FCS
on both parses, but trim it only before transmit. This keeps queue
selection read-only and avoids trimming shared skb data twice.

Fixes: cb17ed29a7 ("mac80211: parse radiotap header when selecting Tx queue")
Signed-off-by: Mariano Baragiola <mbaragiola@linux.com>
Link: https://patch.msgid.link/20260817233521.2747027-1-mbaragiola@linux.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

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Mariano Baragiola 2026-08-17 20:35:21 -03:00 • committed by Johannes Berg

parent 01c15a8b93

commit 9d1365e96a

3 changed files with 7 additions and 5 deletions

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3

include/net/mac80211.h

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2

net/mac80211/iface.c

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7

net/mac80211/tx.c

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