wifi: mac80211: count only matching reservations in reserved switch

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ieee80211_vif_use_reserved_switch() validates a replacement by counting
assigned links on ctx->replace_ctx and treating reservations too
broadly. A link can still be assigned to the old channel context while
holding a reservation that belongs to a different replacement
operation.

That can make the current replacement appear complete too early. If
another link finalizes first, the function can free the
WILL_BE_REPLACED chanctx while the unmatched link and driver still use
it, leading to a use-after-free in later beacon generation.

Require an in-place reservation to point at the current replacement
context, and require the reserved and assigned contexts to be the
matching replacement pair, before counting or moving the link.

Fixes: 5bcae31d9c ("mac80211: implement multi-vif in-place reservations")
Cc: stable@vger.kernel.org
Reported-by: Vega <vega@nebusec.ai>
Signed-off-by: Zhiling Zou <zhilinz@nebusec.ai>
Link: https://patch.msgid.link/4b6c4b8648ab1920c38a40be32c0b1a2797b4ac6.1785726007.git.zhilinz@nebusec.ai
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

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Zhiling Zou 2026-08-03 11:28:22 +08:00 • committed by Johannes Berg

parent b5a051f6b8

commit 437f3727b4

1 changed files with 23 additions and 7 deletions

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net/mac80211/chan.c

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