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=1793831914; b=tsdCJA6GzL7bF9SzTU79lyKAs6jHVH5ltu/jEcGX77WDY+TlKvfmjd2Vu3/VXwSDM9W2 Xq+hfLO634YIlLu+06cusJfYr0g41hqH3Z3rNdj4qU96IvtjnipbJyyB5audY1nwd7oww 17E7XNJhrazUN1bGEuWbMygx6D2Nyz0MYtzah+sT5lejgOIgvoiQIE3QaNvbRECso0kw0 qqnzePszAs5r6v23mf+N0y7EVgEH8s0TMV2gujyy7l6G///RR7CRkB9chE5VwiWE0XeXB GHHD7z66biWzdlgKhh/IgMcJVJMfOXVHRhNEG78NYVdwry6LKd4n/voKNaf/grT8fRQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793831914; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=PDmgC7ECxJxZ0edg+CExE+ahDQSZciNvj0q6MYkqlPQ=; b=iUGxKrCE2P9wRSPYKPCxpdrgArgp6YY5eCj40P+v+d7oVsstL4TSV9RtDSYuq/zFrvn+ gL2l8JFkESeFedKVEoQ4Y6rh75yAJcgsZ5SaqlUeI8PCFPaK0H6aMaviyg+omZpaMd1rM dp68y7Eft5hg+QZ7CbNU8uEMAxDFNiakDufwPjDrS4AD6dtaFea9a3u4mZIVy6PonvNry M71Y3yPuikSoMpEr4v2N/vBRQPNqUdcBMSlO7t5PNo15hQSoa164TeTRvV9mYpvWBzAbz jd1CSLFKoGgrPVcyjjSDrNfXmA8ZGHUCWK9MROOt+FDetuDvSQqIX7mxNZY5zVJhXbg== 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="fCJNJVV/"; 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 1290F606A844; Wed, 4 Nov 2026 22:38:33 +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=fCJNJVV/ Received: by smtp.kernel.org (Postfix) with ESMTPSA id 52D091F000C1; Wed, 4 Nov 2026 22:38:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793831913; bh=PDmgC7ECxJxZ0edg+CExE+ahDQSZciNvj0q6MYkqlPQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=fCJNJVV/yfRIauG7D59+yzCfkvDdWowqxXjUToUJvWhP4QLnenK/zC5RWdjNaprU5 ASs2Ktst8aceH9EftWJ06k9ZDz1nmwKQ9ohQCzMfRmTAhjlj3QfZTI0s78R/2Fn160 EQzlYsHeOaZ37FWi6PK0/5v6vlUrHoE17RsSqs2k= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, ChenXiaoSong , Henry Hu , Namjae Jeon , Sasha Levin Subject: [PATCH 6.18 0990/1005] ksmbd: fix invalid pointer dereference when get_inode_acl() fails Date: Wed, 4 Nov 2026 16:12:03 -0500 Message-ID: <20261104211110.767753887@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261104211043.516122098@linuxfoundation.org> References: <20261104211043.516122098@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: patches@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Henry Hu [ Upstream commit 19d180c7baab7126af5848ed87d5f7b5add0cef2 ] When get_inode_acl() fails, it returns an ERR_PTR(), but ksmbd_acls_fattr() stored that pointer in smb_fattr without checking for errors. Later callers then passed the error pointer to security descriptor helpers or posix_acl_release(), resulting in an invalid pointer dereference. This was reproduced on an XFS-backed share when xfs_get_acl() returned ERR_PTR(-ENOMEM). Querying the SMB ACL from a CIFS client triggered the crash: BUG: unable to handle page fault for address: fffffffffffffff8 RIP: smb_acl_sec_desc_scratch_len+0x58/0x90 [ksmbd] Call Trace: smb2_query_info+0x40d/0x17c0 [ksmbd] handle_ksmbd_work+0x1ca/0x770 [ksmbd] Fix this by checking the return values from get_inode_acl() in ksmbd_acls_fattr(). Treat -EOPNOTSUPP as indicating that no ACL is available, and propagate all other errors to the callers. Update smb2_open() and smb2_get_info_sec() to handle these errors. Cc: stable@vger.kernel.org Fixes: e2f34481b24d ("cifsd: add server-side procedures for SMB3") Assisted-by: Codex:gpt-5.6-sol Reviewed-by: ChenXiaoSong Signed-off-by: Henry Hu Signed-off-by: Namjae Jeon [ sashal: retained the non-const mnt_idmap parameter in ksmbd_acls_fattr() ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- fs/smb/server/smb2pdu.c | 42 ++++++++++++++++++++++++++++++++++-------- 1 file changed, 34 insertions(+), 8 deletions(-) --- a/fs/smb/server/smb2pdu.c +++ b/fs/smb/server/smb2pdu.c @@ -2730,10 +2730,11 @@ static int smb2_create_sd_buffer(struct le32_to_cpu(sd_buf->ccontext.DataLength), true, false); } -static void ksmbd_acls_fattr(struct smb_fattr *fattr, - struct mnt_idmap *idmap, - struct inode *inode) +static int ksmbd_acls_fattr(struct smb_fattr *fattr, + struct mnt_idmap *idmap, + struct inode *inode) { + struct posix_acl *acl; vfsuid_t vfsuid = i_uid_into_vfsuid(idmap, inode); vfsgid_t vfsgid = i_gid_into_vfsgid(idmap, inode); @@ -2744,10 +2745,28 @@ static void ksmbd_acls_fattr(struct smb_ fattr->cf_dacls = NULL; if (IS_ENABLED(CONFIG_FS_POSIX_ACL)) { - fattr->cf_acls = get_inode_acl(inode, ACL_TYPE_ACCESS); - if (S_ISDIR(inode->i_mode)) - fattr->cf_dacls = get_inode_acl(inode, ACL_TYPE_DEFAULT); + acl = get_inode_acl(inode, ACL_TYPE_ACCESS); + if (IS_ERR(acl)) { + if (acl != ERR_PTR(-EOPNOTSUPP)) + return PTR_ERR(acl); + acl = NULL; + } + fattr->cf_acls = acl; + + if (S_ISDIR(inode->i_mode)) { + acl = get_inode_acl(inode, ACL_TYPE_DEFAULT); + if (IS_ERR(acl)) { + if (acl != ERR_PTR(-EOPNOTSUPP)) { + posix_acl_release(fattr->cf_acls); + return PTR_ERR(acl); + } + acl = NULL; + } + fattr->cf_dacls = acl; + } } + + return 0; } enum { @@ -3482,7 +3501,10 @@ int smb2_open(struct ksmbd_work *work) int pntsd_size; size_t scratch_len; - ksmbd_acls_fattr(&fattr, idmap, inode); + rc = ksmbd_acls_fattr(&fattr, idmap, inode); + if (rc) + goto err_out; + scratch_len = smb_acl_sec_desc_scratch_len(&fattr, NULL, 0, OWNER_SECINFO | GROUP_SECINFO | @@ -5953,7 +5975,11 @@ static int smb2_get_info_sec(struct ksmb idmap = file_mnt_idmap(fp->filp); inode = file_inode(fp->filp); - ksmbd_acls_fattr(&fattr, idmap, inode); + rc = ksmbd_acls_fattr(&fattr, idmap, inode); + if (rc) { + ksmbd_fd_put(work, fp); + return rc; + } if (test_share_config_flag(work->tcon->share_conf, KSMBD_SHARE_FLAG_ACL_XATTR))