Date: Fri, 19 Nov 2021 00:02:35 GMT From: "Bjoern A. Zeeb" <bz@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org Subject: git: 32c2c00e3f90 - stable/13 - net80211: correct length check in ieee80211_ies_expand() Message-ID: <202111190002.1AJ02Z4x072431@gitrepo.freebsd.org>
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The branch stable/13 has been updated by bz: URL: https://cgit.FreeBSD.org/src/commit/?id=32c2c00e3f90d3a01a03ebdf7131c7e300da034c commit 32c2c00e3f90d3a01a03ebdf7131c7e300da034c Author: Bjoern A. Zeeb <bz@FreeBSD.org> AuthorDate: 2021-10-06 18:09:39 +0000 Commit: Bjoern A. Zeeb <bz@FreeBSD.org> CommitDate: 2021-11-19 00:01:25 +0000 net80211: correct length check in ieee80211_ies_expand() In ieee80211_ies_expand() we are looping over Elements (also known as Information Elements or IEs). The comment suggests that we assume well-formedness of the IEs themselves. Checking the buffer length being least 2 (1 byte Element ID and 1 byte Length fields) rather than just 1 before accessing ie[1] is still good practise and can prevent and out-of-bounds read in case the input is not behaving according to the comment. Reported by: (coypu sdf.org) admbugs: 857 (cherry picked from commit 09dd08f167812a5fdb516fc98f14dbb43221432f) --- sys/net80211/ieee80211_node.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/sys/net80211/ieee80211_node.c b/sys/net80211/ieee80211_node.c index 5a9677836dbd..3ddb82343efe 100644 --- a/sys/net80211/ieee80211_node.c +++ b/sys/net80211/ieee80211_node.c @@ -1133,7 +1133,7 @@ ieee80211_ies_expand(struct ieee80211_ies *ies) ie = ies->data; ielen = ies->len; - while (ielen > 0) { + while (ielen > 1) { switch (ie[0]) { case IEEE80211_ELEMID_VENDOR: if (iswpaoui(ie))
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