From nobody Sat Jul 25 04:18:26 2026 Received: from mailgw.kylinos.cn (mailgw.kylinos.cn [124.126.103.232]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 64BC33672B5; Sat, 18 Jul 2026 16:22:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=124.126.103.232 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784391772; cv=none; b=erZ8QM/uiXiTeeeEo7f6XKmrKtHK9Wc77AnLKZehhkbKkM1LQ9j6vGUldtt+MBZr50MLQ5j+1kPxjXyL2u/w2TBF6M0ITy1l2UvZvRxu45JCmg6BjLFHVXxXpYlhp6RaKTwuJTxsMusJnIobGjoaBmCO+n4ZRAKzR5AEvMz9eSo= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784391772; c=relaxed/simple; bh=yCH+i4+5rsIhK/AHGMnf4EB9Ce18QyrBgeRKof8MdMM=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=Nkj5reIhZK66THpbywY33Ely3hSvOcrDcD41DJasa53qd9+R+D9CT2804ulA1n6VARG5EAxhgb6gd2HIGaEUebDOow3PbVpWYZJgTQVHpjTmxC2HNSBtZ/7LdVjEyjIHuO9XwH+f0m54bs/wETeprSuBHth6bU8gSUXntnKgDT8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kylinos.cn; spf=pass smtp.mailfrom=kylinos.cn; arc=none smtp.client-ip=124.126.103.232 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kylinos.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=kylinos.cn X-UUID: e5627b7082c411f1aa26b74ffac11d73-20260719 X-CTIC-Tags: HR_CC_COUNT, HR_CC_DOMAIN_COUNT, HR_CC_NAME, HR_CC_NO_NAME, HR_CTE_8B HR_CTT_MISS, HR_DATE_H, HR_DATE_WKD, HR_DATE_ZONE, HR_FROM_DIGIT_LEN HR_FROM_NAME, HR_SJ_LANG, HR_SJ_LEN, HR_SJ_LETTER, HR_SJ_NOR_SYM HR_SJ_PHRASE, HR_SJ_PHRASE_LEN, HR_SJ_WS, HR_TO_COUNT, HR_TO_DOMAIN_COUNT HR_TO_NAME, IP_UNTRUSTED, SRC_UNTRUSTED, IP_UNFAMILIAR, SRC_UNFAMILIAR DN_TRUSTED, SRC_TRUSTED, SA_TRUSTED, SA_EXISTED, SN_TRUSTED SN_EXISTED, SPF_NOPASS, DKIM_NOPASS, DMARC_NOPASS, CIE_GOOD_SPF CIE_UNKNOWN, GTI_FG_BS, GTI_RG_INFO, GTI_C_BU, AMN_GOOD ABX_MISS_RDNS X-CID-P-RULE: Release_Ham X-CID-O-INFO: VERSION:1.3.12,REQID:ac7574a2-6cb7-4c4a-af36-49633c7d4801,IP:10, URL:0,TC:0,Content:0,EDM:25,RT:0,SF:0,FILE:0,BULK:0,RULE:Release_Ham,ACTIO N:release,TS:35 X-CID-INFO: VERSION:1.3.12,REQID:ac7574a2-6cb7-4c4a-af36-49633c7d4801,IP:10,UR L:0,TC:0,Content:0,EDM:25,RT:0,SF:0,FILE:0,BULK:0,RULE:Release_Ham,ACTION: release,TS:35 X-CID-META: VersionHash:e7bac3a,CLOUDID:1aa5aa4feb08d70b2bef6259f6400187,BulkI D:2607190022408S6OPDZG,BulkQuantity:0,Recheck:0,SF:10|66|78|102|127|865|89 8,TC:nil,Content:0|15|50,EDM:5,IP:-2,URL:0,File:nil,RT:nil,Bulk:nil,QS:nil ,BEC:nil,COL:0,OSI:0,OSA:0,AV:0,LES:1,SPR:NO,DKR:0,DKP:0,BRR:0,BRE:0,ARC:0 X-CID-BVR: 2,SSN|SDN X-CID-BAS: 2,SSN|SDN,0,_ X-CID-FACTOR: TF_CID_SPAM_SNR X-CID-RHF: D41D8CD98F00B204E9800998ECF8427E X-UUID: e5627b7082c411f1aa26b74ffac11d73-20260719 X-User: liqiang01@kylinos.cn Received: from cvdaxia.localdomain [(104.194.206.225)] by mailgw.kylinos.cn (envelope-from ) (Generic MTA with TLSv1.3 TLS_AES_256_GCM_SHA384 256/256) with ESMTP id 240361366; Sun, 19 Jul 2026 00:22:39 +0800 From: Li Qiang To: Steve French Cc: linux-cifs@vger.kernel.org, samba-technical@lists.samba.org, linux-kernel@vger.kernel.org, Li Qiang Subject: [PATCH] cifs: validate idmap key payload length Date: Sun, 19 Jul 2026 00:22:27 +0800 Message-ID: <20260718162228.193366-1-liqiang01@kylinos.cn> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" The cifs.idmap key type stores its payload length in key->datalen, which is limited to U16_MAX. Accepting a larger key payload truncates the recorded length and can make later users interpret the payload using inconsistent bounds. Reject oversized preparsed payloads before allocating or copying them. This keeps key->datalen consistent with the stored data for both inline and separately allocated idmap payloads. Signed-off-by: Li Qiang --- fs/smb/client/cifsacl.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/smb/client/cifsacl.c b/fs/smb/client/cifsacl.c index 07cf0e578233..d6c38989170f 100644 --- a/fs/smb/client/cifsacl.c +++ b/fs/smb/client/cifsacl.c @@ -68,6 +68,9 @@ cifs_idmap_key_instantiate(struct key *key, struct key_pr= eparsed_payload *prep) { char *payload; =20 + if (prep->datalen > U16_MAX) + return -EINVAL; + /* * If the payload is less than or equal to the size of a pointer, then * an allocation here is wasteful. Just copy the data directly to the --=20 2.43.0