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authorSteve French <stfrench@microsoft.com>2020-01-17 04:55:33 +0300
committerSteve French <stfrench@microsoft.com>2020-01-27 04:24:17 +0300
commit643fbceef48e5b22bf8e0905f903e908b5d2ba69 (patch)
tree54a07ac880d8fd9800ddf0e9440c01856f712434 /fs/cifs
parent438471b67963b8267e94beab383b6d6fc41b3481 (diff)
downloadlinux-643fbceef48e5b22bf8e0905f903e908b5d2ba69.tar.xz
smb3: fix default permissions on new files when mounting with modefromsid
When mounting with "modefromsid" mount parm most servers will require that some default permissions are given to users in the ACL on newly created files, files created with the new 'sd context' - when passing in an sd context on create, permissions are not inherited from the parent directory, so in addition to the ACE with the special SID which contains the mode, we also must pass in an ACE allowing users to access the file (GENERIC_ALL for authenticated users seemed like a reasonable default, although later we could allow a mount option or config switch to make it GENERIC_ALL for EVERYONE special sid). CC: Stable <stable@vger.kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-By: Ronnie Sahlberg <lsahlber@redhat.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Diffstat (limited to 'fs/cifs')
-rw-r--r--fs/cifs/cifsacl.c20
-rw-r--r--fs/cifs/cifsproto.h1
-rw-r--r--fs/cifs/smb2pdu.c11
3 files changed, 29 insertions, 3 deletions
diff --git a/fs/cifs/cifsacl.c b/fs/cifs/cifsacl.c
index 96ae72b556ac..fb41e51dd574 100644
--- a/fs/cifs/cifsacl.c
+++ b/fs/cifs/cifsacl.c
@@ -802,6 +802,26 @@ static void parse_dacl(struct cifs_acl *pdacl, char *end_of_acl,
return;
}
+unsigned int setup_authusers_ACE(struct cifs_ace *pntace)
+{
+ int i;
+ unsigned int ace_size = 20;
+
+ pntace->type = ACCESS_ALLOWED_ACE_TYPE;
+ pntace->flags = 0x0;
+ pntace->access_req = cpu_to_le32(GENERIC_ALL);
+ pntace->sid.num_subauth = 1;
+ pntace->sid.revision = 1;
+ for (i = 0; i < NUM_AUTHS; i++)
+ pntace->sid.authority[i] = sid_authusers.authority[i];
+
+ pntace->sid.sub_auth[0] = sid_authusers.sub_auth[0];
+
+ /* size = 1 + 1 + 2 + 4 + 1 + 1 + 6 + (psid->num_subauth*4) */
+ pntace->size = cpu_to_le16(ace_size);
+ return ace_size;
+}
+
/*
* Fill in the special SID based on the mode. See
* http://technet.microsoft.com/en-us/library/hh509017(v=ws.10).aspx
diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index f6f3cc90cd18..948bf3474db1 100644
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -213,6 +213,7 @@ extern struct cifs_ntsd *get_cifs_acl_by_fid(struct cifs_sb_info *,
const struct cifs_fid *, u32 *);
extern int set_cifs_acl(struct cifs_ntsd *, __u32, struct inode *,
const char *, int);
+extern unsigned int setup_authusers_ACE(struct cifs_ace *pace);
extern unsigned int setup_special_mode_ACE(struct cifs_ace *pace, __u64 nmode);
extern void dequeue_mid(struct mid_q_entry *mid, bool malformed);
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index 64d5a36a1901..7edba3e6d5e6 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -2199,13 +2199,14 @@ create_sd_buf(umode_t mode, unsigned int *len)
struct cifs_ace *pace;
unsigned int sdlen, acelen;
- *len = roundup(sizeof(struct crt_sd_ctxt) + sizeof(struct cifs_ace), 8);
+ *len = roundup(sizeof(struct crt_sd_ctxt) + sizeof(struct cifs_ace) * 2,
+ 8);
buf = kzalloc(*len, GFP_KERNEL);
if (buf == NULL)
return buf;
sdlen = sizeof(struct smb3_sd) + sizeof(struct smb3_acl) +
- sizeof(struct cifs_ace);
+ 2 * sizeof(struct cifs_ace);
buf->ccontext.DataOffset = cpu_to_le16(offsetof
(struct crt_sd_ctxt, sd));
@@ -2232,8 +2233,12 @@ create_sd_buf(umode_t mode, unsigned int *len)
/* create one ACE to hold the mode embedded in reserved special SID */
pace = (struct cifs_ace *)(sizeof(struct crt_sd_ctxt) + (char *)buf);
acelen = setup_special_mode_ACE(pace, (__u64)mode);
+ /* and one more ACE to allow access for authenticated users */
+ pace = (struct cifs_ace *)(acelen + (sizeof(struct crt_sd_ctxt) +
+ (char *)buf));
+ acelen += setup_authusers_ACE(pace);
buf->acl.AclSize = cpu_to_le16(sizeof(struct cifs_acl) + acelen);
- buf->acl.AceCount = cpu_to_le16(1);
+ buf->acl.AceCount = cpu_to_le16(2);
return buf;
}