wifi: cfg80211: reject duplicate wiphy cipher suite entries

Duplicate entries in wiphy->cipher_suites do not describe any
additional capability, but cfg80211 currently accepts them and leaves
individual consumers to deal with them.

One such consumer is the WEXT compatibility code, which appends a WEP
key length for each WEP cipher entry it sees. Repeated WEP entries can
therefore overflow the fixed iw_range::encoding_size array returned by
SIOCGIWRANGE.

Reject duplicate cipher suite entries in wiphy_register() instead.
This keeps the cipher suite invariant in one place and makes malformed
wiphy descriptions fail early with -EINVAL, rather than relying on a
single cfg80211 user to handle duplicates correctly.

Reported-by: Yifan Wu <yifanwucs@gmail.com>
Reported-by: Juefei Pu <tomapufckgml@gmail.com>
Co-developed-by: Yuan Tan <yuantan098@gmail.com>
Signed-off-by: Yuan Tan <yuantan098@gmail.com>
Suggested-by: Xin Liu <bird@lzu.edu.cn>
Signed-off-by: Yuqi Xu <xuyuqiabc@gmail.com>
Signed-off-by: Ren Wei <n05ec@lzu.edu.cn>
Link: https://patch.msgid.link/20260413123000.1480661-1-n05ec@lzu.edu.cn
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

0 files changed, 0 insertions, 0 deletions