5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Deepanshu Kartikey [ Upstream commit a2f5286ca4f304d3fd469f01b96b518608912a5c ] The KASAN allocation trace shows that a malformed IE buffer is stored via SIOCSIWGENIE (cfg80211_wext_siwgenie()) without any validation. The crash trace shows that a subsequent SIOCSIWESSID triggers a connection attempt which calls cfg80211_sme_get_conn_ies() to process the stored IE buffer, causing: - An out-of-bounds read in skip_ie() which reads ies[pos+1] (the length byte) past the end of the 1-byte buffer. - An integer underflow in the memcpy size argument when offs returned by ieee80211_ie_split() exceeds ies_len, causing unsigned subtraction to wrap to SIZE_MAX and triggering a fortify panic. Fix this by validating the IE buffer in cfg80211_wext_siwgenie() before storing it. Reported-by: syzbot+cc867e537e4bd36f69bb@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=cc867e537e4bd36f69bb Signed-off-by: Deepanshu Kartikey Link: https://patch.msgid.link/20260725142028.32560-1-kartikey406@gmail.com [drop unnecessary ie_len check, update commit message] Signed-off-by: Johannes Berg Signed-off-by: Sasha Levin --- net/wireless/wext-sme.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/net/wireless/wext-sme.c b/net/wireless/wext-sme.c index 193a18a531423..1919290d1208d 100644 --- a/net/wireless/wext-sme.c +++ b/net/wireless/wext-sme.c @@ -333,6 +333,15 @@ int cfg80211_wext_siwgenie(struct net_device *dev, goto out; if (ie_len) { + const struct element *elem; + + for_each_element(elem, extra, ie_len) { + /* nothing */ + } + + if (!for_each_element_completed(elem, extra, ie_len)) + return -EINVAL; + ie = kmemdup(extra, ie_len, GFP_KERNEL); if (!ie) { err = -ENOMEM; -- 2.53.0