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Address review: init_user_ns in nfs4proc
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Instead of rolling our own mapping, instead use the existing upstream
functions to do this.
- nfs_map_name_to_uid
- nfs_map_group_to_gid
- nfs_map_uid_to_name
- nfs_map_gid_to_group
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@bmeagherix
bmeagherix committed Dec 1, 2023
1 parent a252ff8 commit 74a2e72
Showing 1 changed file with 33 additions and 60 deletions.
93 changes: 33 additions & 60 deletions fs/nfs/nfs4proc.c
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Original file line number Diff line number Diff line change
Expand Up @@ -73,9 +73,6 @@

#if CONFIG_TRUENAS
#include "../nfs_common/nfs41acl_xdr.h"

/* 0xFFFFFFFFFFFFFFFF == 18446744073709551615, len('18446744073709551615') == 20 */
#define U64_STRBUF_SIZE 21
#endif /* CONFIG_TRUENAS */

#define NFSDBG_FACILITY NFSDBG_PROC
Expand Down Expand Up @@ -7835,12 +7832,12 @@ static int nfs4_acl_get_whotype(char *p, u32 len)
* Return the number of bytes (including the leading nbytes and
* any padding necessary)
*/
static int nfs4_ace_encode_who(struct nfs4_ace *ace, char *buf)
static int nfs4_ace_encode_who(struct nfs_server *server, struct nfs4_ace *ace, char *buf)
{
u32 *p = (u32 *)buf;
int count = -EINVAL;
const char *pstr = NULL;
char idbuf[U64_STRBUF_SIZE]; /* Future-proof in case uid_t / gid_t change size */
char idbuf[IDMAP_NAMESZ];
int total_bytes, pad_count;

/*
Expand All @@ -7851,16 +7848,10 @@ static int nfs4_ace_encode_who(struct nfs4_ace *ace, char *buf)
* pstr will point into s2t_map.
*/
if (ace->whotype == NFS4_ACL_WHO_NAMED) {
if (ace->flag & NFS4_ACE_IDENTIFIER_GROUP) {
gid_t gid = from_kgid_munged(&init_user_ns, ace->who_gid);

snprintf(idbuf, sizeof(idbuf), "%lu", (unsigned long)gid);
} else {
uid_t uid = from_kuid_munged(&init_user_ns, ace->who_uid);

snprintf(idbuf, sizeof(idbuf), "%lu", (unsigned long)uid);
}
count = strlen(idbuf);
if (ace->flag & NFS4_ACE_IDENTIFIER_GROUP)
count = nfs_map_gid_to_group(server, ace->who_gid, idbuf, IDMAP_NAMESZ);
else
count = nfs_map_uid_to_name(server, ace->who_uid, idbuf, IDMAP_NAMESZ);
} else {
int i;

Expand Down Expand Up @@ -7903,34 +7894,12 @@ static int nfs4_ace_encode_who(struct nfs4_ace *ace, char *buf)
return total_bytes;
}

/*
* Convert the specified (numeric) name into a unsigned long ID.
*
* Do this rather than u32 in an effort to future-proof.
*
* Returns true on success.
*/
static bool numeric_name_to_id(const char *name, u32 namelen, unsigned long *id)
{
int ret;
char buf[U64_STRBUF_SIZE];

if (id && (namelen + 1 > sizeof(buf)))
/* no id buffer or too long to represent a 64-bit id: */
return false;
/* Just to make sure it's null-terminated: */
memcpy(buf, name, namelen);
buf[namelen] = '\0';
ret = kstrtoul(buf, 10, id);
return ret == 0;
}

/*
* Decode the XDR data supplied in data parameter into an ACE.
*
* Upon success 0 is returned, and the data parameter is advanced.
*/
static int nfs4_decode_nfsace4(void **data, struct nfs4_ace *ace)
static int nfs4_decode_nfsace4(struct nfs_server *server, void **data, struct nfs4_ace *ace)
{
u32 *p = *data;
u32 length;
Expand All @@ -7956,31 +7925,32 @@ static int nfs4_decode_nfsace4(void **data, struct nfs4_ace *ace)
ace->whotype = nfs4_acl_get_whotype((char *)p, length);

if (ace->whotype == NFS4_ACL_WHO_NAMED) {
/*
* We're just going to support numeric IDs here.
* (it's very expensive to do otherwise)
*/
unsigned long id = -1;

if (numeric_name_to_id((const char *)p, length, &id)) {
if (ace->flag & NFS4_ACE_IDENTIFIER_GROUP) {
ace->who_gid = make_kgid(&init_user_ns, id);
if (ace->flag & NFS4_ACE_IDENTIFIER_GROUP) {
if (length <= 0 || nfs_map_group_to_gid(server, (const char *)p, length,
&ace->who_gid) != 0) {
pr_err("NFS: %s Failed to obtain who_gid: %.*s", __func__,
length, (char *)p);
error = -EINVAL;
} else {
if (!gid_valid(ace->who_gid)) {
pr_err("NFS: %s Invalid who_gid: %.*s", __func__,
length, (char *)p);
error = -EINVAL;
}
}
} else {
if (length <= 0 || nfs_map_name_to_uid(server, (const char *)p, length,
&ace->who_uid) != 0) {
pr_err("NFS: %s Failed to obtain who_uid: %.*s", __func__,
length, (char *)p);
error = -EINVAL;
} else {
ace->who_uid = make_kuid(&init_user_ns, id);
if (!uid_valid(ace->who_uid)) {
if (!gid_valid(ace->who_gid)) {
pr_err("NFS: %s Invalid who_uid: %.*s", __func__,
length, (char *)p);
error = -EINVAL;
}
}
} else {
pr_err("NFS: %s Non-numeric who: %.*s", __func__, length, (char *)p);
error = -EINVAL;
}
}
/*
Expand All @@ -8006,8 +7976,8 @@ static int nfs4_decode_nfsace4(void **data, struct nfs4_ace *ace)
*
* This is similar to nfsd4_decode_acl
*/
static int nfs4_aclbuf_decode(void *buf, size_t buflen, enum nfs4_acl_type type,
struct nfs4_acl **pacl)
static int nfs4_aclbuf_decode(struct nfs_server *server, void *buf, size_t buflen,
enum nfs4_acl_type type, struct nfs4_acl **pacl)
{
u32 acl_flag, count;
u32 *p = buf;
Expand Down Expand Up @@ -8038,7 +8008,7 @@ static int nfs4_aclbuf_decode(void *buf, size_t buflen, enum nfs4_acl_type type,
if ((void *)p >= (buf + buflen))
status = -EINVAL;
else
status = nfs4_decode_nfsace4((void **)&p, ace);
status = nfs4_decode_nfsace4(server, (void **)&p, ace);
if (status) {
kfree(acl);
return status;
Expand All @@ -8055,12 +8025,14 @@ static int nfs4_aclbuf_decode(void *buf, size_t buflen, enum nfs4_acl_type type,
* Returns 0 on success, and populates the buf and buflen parameters. The
* buf must be freed by the caller.
*/
static int nfs4_encode_acl_to_buf(struct nfs4_acl *acl, void **buf, size_t *buflen)
static int nfs4_encode_acl_to_buf(struct inode *inode, struct nfs4_acl *acl,
void **buf, size_t *buflen)
{
int byte_count = 0;
struct nfs4_ace *ace;
void *xdrbuf;
u32 *p;
struct nfs_server *server = NFS_SERVER(inode);

/*
* First count how many bytes we will need.
Expand All @@ -8070,7 +8042,7 @@ static int nfs4_encode_acl_to_buf(struct nfs4_acl *acl, void **buf, size_t *bufl
int who_bytes;

byte_count += 12; /* ace type, flag, access_mask */
who_bytes = nfs4_ace_encode_who(ace, NULL);
who_bytes = nfs4_ace_encode_who(server, ace, NULL);
if (who_bytes < 0) {
pr_err("NFS: %s Failed to determine bytes for ACE (%d)", __func__,
who_bytes);
Expand All @@ -8094,7 +8066,7 @@ static int nfs4_encode_acl_to_buf(struct nfs4_acl *acl, void **buf, size_t *bufl
*p++ = htonl(ace->type);
*p++ = htonl(ace->flag);
*p++ = htonl(ace->access_mask);
bytes = nfs4_ace_encode_who(ace, (char *)p);
bytes = nfs4_ace_encode_who(server, ace, (char *)p);
p += (bytes >> 2); /* >> 2 because pointer to u32 */
}

Expand Down Expand Up @@ -8154,7 +8126,7 @@ static int nfs4_xattr_set_nfs4_acl_xdr(const struct xattr_handler *handler,
goto acl_out;

/* Encode struct nfs4_acl to DACL XDR */
error = nfs4_encode_acl_to_buf(acl, &xdrbuf, &xdrbuflen);
error = nfs4_encode_acl_to_buf(inode, acl, &xdrbuf, &xdrbuflen);
if (error)
goto acl_out;

Expand All @@ -8177,6 +8149,7 @@ static int nfs4_xattr_get_nfs4_acl_xdr(const struct xattr_handler *handler,
int ret = 0;
ssize_t dacl_size, acl_size;
void *dacl_buf = NULL;
struct nfs_server *server = NFS_SERVER(inode);

/*
* In order to present this view (system.nfs4_acl_xdr) of our ZFS ACL
Expand Down Expand Up @@ -8221,7 +8194,7 @@ static int nfs4_xattr_get_nfs4_acl_xdr(const struct xattr_handler *handler,
*/
struct nfs4_acl *acl = NULL;

acl_size = nfs4_aclbuf_decode(dacl_buf, dacl_size, NFS4ACL_DACL, &acl);
acl_size = nfs4_aclbuf_decode(server, dacl_buf, dacl_size, NFS4ACL_DACL, &acl);
if (acl_size < 0) {
pr_err("NFS: %s Failed to decode DACL: %zu", __func__, acl_size);
ret = -EINVAL;
Expand Down

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