From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793701230; b=mXR4HLt/+8g2e6gI72ztviorISWkvpxP1VQNiOd7N5xWHwXJQ2m5y41XGGNBnzG9Dmci wbRJzO5mRkiZd5SEksGcnu2h0BH6QYoD+mCFr0bQs0qOca6Ct///YPHH2YBnSaeXV5vbA OrKElwdGn0tHDA6mHGsuiAE0ofTqKfzbATlT94q1SX/zM8fw85IUVdInhac1q3NJbxBMI wG1qVXV2BPuu1EME4zH3m+OY3Uv1E8UUkSGQLWZMYtNI0JmFq4H74O/LfJSEg1XxCf92X aroz9imcPxONUbL4LQx5mHxOBt5NafCcZpEqSTslD7lw1Zvb18hIOEI+wL9n2Pjc+TA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793701230; h=Received:DKIM-Signature:Subject:To:Cc:From:Date:Message-ID: MIME-Version:Content-Type:Content-Transfer-Encoding; bh=2EJXCi/VgyF8v15fNbxqBC+vrmADEe8DYdYs8VcIOrk=; b=nf0+9CwnXt8KfGhs5T4q7k1VC/pV6tYB0/qMBXoD22rY82GW+Zmu7M9Su2rOTsT99bPP l3l4UMkrRISBI7uVMu4+NodbE1DYhHO2QOD6n7kdWGVpXlHN+Fj8CZUdLg04VHLwSN9ym y6K4hRN1NpGKMp83Cxas12MdTmgXz3p4ztLllc+WFR+Ym1n8QkiD+S6cRg1cLxxJaoQsx xB84NTkXrU88MbH8mr8gdltAMFY6T/LkguRhHDTBX71VBmoIIDqZG3FSBQVTz6xAKzS2m Q8IjpRlzt+1u4xhIafEWbOsZg8b43reIjA5RG/HHN95KbrVb5FiUhhdAMEoQvs6erOA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=U5tcOg9Q; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9E100606BFBF for ; Tue, 3 Nov 2026 10:20:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=U5tcOg9Q Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3659F1F00A1A; Tue, 3 Nov 2026 10:20:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793701229; bh=2EJXCi/VgyF8v15fNbxqBC+vrmADEe8DYdYs8VcIOrk=; h=Subject:To:Cc:From:Date; b=U5tcOg9QHVll3EXwzCit0oM1H6EjsBde8XL+pkUEP+ORHrWAGX7FSxAKo6/8wdcBu UfX19Ebipja9ntnVxQ+YP/m8fhZgx04U7WhMr88kpCwRbMZalrlvc2seBROW9xQ43W +q25khIIB6c1dFemkjQz8C465iKCVJlbqUoEYm7E= Subject: FAILED: patch "[PATCH] ksmbd: validate security descriptor offsets before pointer" failed to apply to 5.15-stable tree To: linkinjeon@kernel.org,ratnaker.gautam@kuleuven.be Cc: From: Date: Tue, 03 Nov 2026 11:20:19 +0100 Message-ID: <2026110319-apple-willow-5e9e@gregkh> X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x 3474e1a304fbf9f7c996b24adcd519e031227a90 # git commit -s git send-email --to '' --in-reply-to '2026110319-apple-willow-5e9e@gregkh' --subject-prefix 'PATCH 5.15.y' 'HEAD^..' Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 3474e1a304fbf9f7c996b24adcd519e031227a90 Mon Sep 17 00:00:00 2001 From: Namjae Jeon Date: Sat, 17 Oct 2026 09:44:48 +0900 Subject: [PATCH] ksmbd: validate security descriptor offsets before pointer arithmetic parse_sec_desc() constructs SID and DACL pointers by adding untrusted 32-bit offsets to the security descriptor before checking their bounds. The existing checks reject offsets into the descriptor header, but do not reject offsets beyond the descriptor's length. On a 32-bit kernel, a large offset can wrap the pointer before the descriptor. The end-only checks in parse_sid() and parse_dacl() can then accept it, allowing an authenticated SMB2 SET_INFO request to access memory outside the security descriptor and fault the kernel. Check each nonzero offset against acl_len before constructing its pointer. Initialize the optional owner and group SID pointers to NULL so an omitted SID remains absent when parsing the DACL. Fixes: 0626e6641f6b ("cifsd: add server handler for central processing and tranport layers") Cc: stable@vger.kernel.org Reported-by: Ratnaker Gautam Signed-off-by: Namjae Jeon diff --git a/fs/smb/server/smbacl.c b/fs/smb/server/smbacl.c index 96428df33b43..f3b1efd8e85a 100644 --- a/fs/smb/server/smbacl.c +++ b/fs/smb/server/smbacl.c @@ -900,7 +900,7 @@ int parse_sec_desc(const struct mnt_idmap *idmap, struct smb_ntsd *pntsd, int acl_len, struct smb_fattr *fattr) { int rc = 0; - struct smb_sid *owner_sid_ptr, *group_sid_ptr; + struct smb_sid *owner_sid_ptr = NULL, *group_sid_ptr = NULL; struct smb_acl *dacl_ptr; /* no need for SACL ptr */ char *end_of_acl = ((char *)pntsd) + acl_len; __u32 dacloffset; @@ -912,12 +912,7 @@ int parse_sec_desc(const struct mnt_idmap *idmap, struct smb_ntsd *pntsd, if (acl_len < sizeof(struct smb_ntsd)) return -EINVAL; - owner_sid_ptr = (struct smb_sid *)((char *)pntsd + - le32_to_cpu(pntsd->osidoffset)); - group_sid_ptr = (struct smb_sid *)((char *)pntsd + - le32_to_cpu(pntsd->gsidoffset)); dacloffset = le32_to_cpu(pntsd->dacloffset); - dacl_ptr = (struct smb_acl *)((char *)pntsd + dacloffset); ksmbd_debug(SMB, "revision %d type 0x%x ooffset 0x%x goffset 0x%x sacloffset 0x%x dacloffset 0x%x\n", pntsd->revision, pntsd->type, le32_to_cpu(pntsd->osidoffset), @@ -933,9 +928,12 @@ int parse_sec_desc(const struct mnt_idmap *idmap, struct smb_ntsd *pntsd, pntsd->type = cpu_to_le16(DACL_PRESENT); if (pntsd->osidoffset) { - if (le32_to_cpu(pntsd->osidoffset) < sizeof(struct smb_ntsd)) + if (le32_to_cpu(pntsd->osidoffset) < sizeof(struct smb_ntsd) || + le32_to_cpu(pntsd->osidoffset) >= acl_len) return -EINVAL; + owner_sid_ptr = (struct smb_sid *)((char *)pntsd + + le32_to_cpu(pntsd->osidoffset)); rc = parse_sid(owner_sid_ptr, end_of_acl); if (rc) { pr_err("%s: Error %d parsing Owner SID\n", __func__, rc); @@ -951,9 +949,12 @@ int parse_sec_desc(const struct mnt_idmap *idmap, struct smb_ntsd *pntsd, } if (pntsd->gsidoffset) { - if (le32_to_cpu(pntsd->gsidoffset) < sizeof(struct smb_ntsd)) + if (le32_to_cpu(pntsd->gsidoffset) < sizeof(struct smb_ntsd) || + le32_to_cpu(pntsd->gsidoffset) >= acl_len) return -EINVAL; + group_sid_ptr = (struct smb_sid *)((char *)pntsd + + le32_to_cpu(pntsd->gsidoffset)); rc = parse_sid(group_sid_ptr, end_of_acl); if (rc) { pr_err("%s: Error %d mapping Owner SID to gid\n", @@ -975,9 +976,10 @@ int parse_sec_desc(const struct mnt_idmap *idmap, struct smb_ntsd *pntsd, pntsd->type |= cpu_to_le16(DACL_PROTECTED); if (dacloffset) { - if (dacloffset < sizeof(struct smb_ntsd)) + if (dacloffset < sizeof(struct smb_ntsd) || dacloffset >= acl_len) return -EINVAL; + dacl_ptr = (struct smb_acl *)((char *)pntsd + dacloffset); rc = parse_dacl(idmap, dacl_ptr, end_of_acl, owner_sid_ptr, group_sid_ptr, fattr); if (rc)