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Subject[PATCH 4.14 048/164] CIFS: refactor crypto shash/sdesc allocation&free
Date
4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Aurelien Aptel <aaptel@suse.com>

commit 82fb82be05585426405667dd5f0510aa953ba439 upstream.

shash and sdesc and always allocated and freed together.
* abstract this in new functions cifs_alloc_hash() and cifs_free_hash().
* make smb2/3 crypto allocation independent from each other.

Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
fs/cifs/cifsencrypt.c | 78 ++++--------------------------------------------
fs/cifs/cifsproto.h | 5 +++
fs/cifs/link.c | 25 +++------------
fs/cifs/misc.c | 54 +++++++++++++++++++++++++++++++++
fs/cifs/smb2transport.c | 75 +++++++++-------------------------------------
fs/cifs/smbencrypt.c | 25 +++------------
6 files changed, 91 insertions(+), 171 deletions(-)

--- a/fs/cifs/cifsencrypt.c
+++ b/fs/cifs/cifsencrypt.c
@@ -36,37 +36,6 @@
#include <crypto/skcipher.h>
#include <crypto/aead.h>

-static int
-cifs_crypto_shash_md5_allocate(struct TCP_Server_Info *server)
-{
- int rc;
- unsigned int size;
-
- if (server->secmech.sdescmd5 != NULL)
- return 0; /* already allocated */
-
- server->secmech.md5 = crypto_alloc_shash("md5", 0, 0);
- if (IS_ERR(server->secmech.md5)) {
- cifs_dbg(VFS, "could not allocate crypto md5\n");
- rc = PTR_ERR(server->secmech.md5);
- server->secmech.md5 = NULL;
- return rc;
- }
-
- size = sizeof(struct shash_desc) +
- crypto_shash_descsize(server->secmech.md5);
- server->secmech.sdescmd5 = kmalloc(size, GFP_KERNEL);
- if (!server->secmech.sdescmd5) {
- crypto_free_shash(server->secmech.md5);
- server->secmech.md5 = NULL;
- return -ENOMEM;
- }
- server->secmech.sdescmd5->shash.tfm = server->secmech.md5;
- server->secmech.sdescmd5->shash.flags = 0x0;
-
- return 0;
-}
-
int __cifs_calc_signature(struct smb_rqst *rqst,
struct TCP_Server_Info *server, char *signature,
struct shash_desc *shash)
@@ -132,13 +101,10 @@ static int cifs_calc_signature(struct sm
if (!rqst->rq_iov || !signature || !server)
return -EINVAL;

- if (!server->secmech.sdescmd5) {
- rc = cifs_crypto_shash_md5_allocate(server);
- if (rc) {
- cifs_dbg(VFS, "%s: Can't alloc md5 crypto\n", __func__);
- return -1;
- }
- }
+ rc = cifs_alloc_hash("md5", &server->secmech.md5,
+ &server->secmech.sdescmd5);
+ if (rc)
+ return -1;

rc = crypto_shash_init(&server->secmech.sdescmd5->shash);
if (rc) {
@@ -663,37 +629,6 @@ CalcNTLMv2_response(const struct cifs_se
return rc;
}

-static int crypto_hmacmd5_alloc(struct TCP_Server_Info *server)
-{
- int rc;
- unsigned int size;
-
- /* check if already allocated */
- if (server->secmech.sdeschmacmd5)
- return 0;
-
- server->secmech.hmacmd5 = crypto_alloc_shash("hmac(md5)", 0, 0);
- if (IS_ERR(server->secmech.hmacmd5)) {
- cifs_dbg(VFS, "could not allocate crypto hmacmd5\n");
- rc = PTR_ERR(server->secmech.hmacmd5);
- server->secmech.hmacmd5 = NULL;
- return rc;
- }
-
- size = sizeof(struct shash_desc) +
- crypto_shash_descsize(server->secmech.hmacmd5);
- server->secmech.sdeschmacmd5 = kmalloc(size, GFP_KERNEL);
- if (!server->secmech.sdeschmacmd5) {
- crypto_free_shash(server->secmech.hmacmd5);
- server->secmech.hmacmd5 = NULL;
- return -ENOMEM;
- }
- server->secmech.sdeschmacmd5->shash.tfm = server->secmech.hmacmd5;
- server->secmech.sdeschmacmd5->shash.flags = 0x0;
-
- return 0;
-}
-
int
setup_ntlmv2_rsp(struct cifs_ses *ses, const struct nls_table *nls_cp)
{
@@ -757,9 +692,10 @@ setup_ntlmv2_rsp(struct cifs_ses *ses, c

mutex_lock(&ses->server->srv_mutex);

- rc = crypto_hmacmd5_alloc(ses->server);
+ rc = cifs_alloc_hash("hmac(md5)",
+ &ses->server->secmech.hmacmd5,
+ &ses->server->secmech.sdeschmacmd5);
if (rc) {
- cifs_dbg(VFS, "could not crypto alloc hmacmd5 rc %d\n", rc);
goto unlock;
}

--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -538,4 +538,9 @@ enum securityEnum cifs_select_sectype(st
struct cifs_aio_ctx *cifs_aio_ctx_alloc(void);
void cifs_aio_ctx_release(struct kref *refcount);
int setup_aio_ctx_iter(struct cifs_aio_ctx *ctx, struct iov_iter *iter, int rw);
+
+int cifs_alloc_hash(const char *name, struct crypto_shash **shash,
+ struct sdesc **sdesc);
+void cifs_free_hash(struct crypto_shash **shash, struct sdesc **sdesc);
+
#endif /* _CIFSPROTO_H */
--- a/fs/cifs/link.c
+++ b/fs/cifs/link.c
@@ -50,25 +50,12 @@ static int
symlink_hash(unsigned int link_len, const char *link_str, u8 *md5_hash)
{
int rc;
- unsigned int size;
- struct crypto_shash *md5;
- struct sdesc *sdescmd5;
+ struct crypto_shash *md5 = NULL;
+ struct sdesc *sdescmd5 = NULL;

- md5 = crypto_alloc_shash("md5", 0, 0);
- if (IS_ERR(md5)) {
- rc = PTR_ERR(md5);
- cifs_dbg(VFS, "%s: Crypto md5 allocation error %d\n",
- __func__, rc);
- return rc;
- }
- size = sizeof(struct shash_desc) + crypto_shash_descsize(md5);
- sdescmd5 = kmalloc(size, GFP_KERNEL);
- if (!sdescmd5) {
- rc = -ENOMEM;
+ rc = cifs_alloc_hash("md5", &md5, &sdescmd5);
+ if (rc)
goto symlink_hash_err;
- }
- sdescmd5->shash.tfm = md5;
- sdescmd5->shash.flags = 0x0;

rc = crypto_shash_init(&sdescmd5->shash);
if (rc) {
@@ -85,9 +72,7 @@ symlink_hash(unsigned int link_len, cons
cifs_dbg(VFS, "%s: Could not generate md5 hash\n", __func__);

symlink_hash_err:
- crypto_free_shash(md5);
- kfree(sdescmd5);
-
+ cifs_free_hash(&md5, &sdescmd5);
return rc;
}

--- a/fs/cifs/misc.c
+++ b/fs/cifs/misc.c
@@ -848,3 +848,57 @@ setup_aio_ctx_iter(struct cifs_aio_ctx *
iov_iter_bvec(&ctx->iter, ITER_BVEC | rw, ctx->bv, npages, ctx->len);
return 0;
}
+
+/**
+ * cifs_alloc_hash - allocate hash and hash context together
+ *
+ * The caller has to make sure @sdesc is initialized to either NULL or
+ * a valid context. Both can be freed via cifs_free_hash().
+ */
+int
+cifs_alloc_hash(const char *name,
+ struct crypto_shash **shash, struct sdesc **sdesc)
+{
+ int rc = 0;
+ size_t size;
+
+ if (*sdesc != NULL)
+ return 0;
+
+ *shash = crypto_alloc_shash(name, 0, 0);
+ if (IS_ERR(*shash)) {
+ cifs_dbg(VFS, "could not allocate crypto %s\n", name);
+ rc = PTR_ERR(*shash);
+ *shash = NULL;
+ *sdesc = NULL;
+ return rc;
+ }
+
+ size = sizeof(struct shash_desc) + crypto_shash_descsize(*shash);
+ *sdesc = kmalloc(size, GFP_KERNEL);
+ if (*sdesc == NULL) {
+ cifs_dbg(VFS, "no memory left to allocate crypto %s\n", name);
+ crypto_free_shash(*shash);
+ *shash = NULL;
+ return -ENOMEM;
+ }
+
+ (*sdesc)->shash.tfm = *shash;
+ (*sdesc)->shash.flags = 0x0;
+ return 0;
+}
+
+/**
+ * cifs_free_hash - free hash and hash context together
+ *
+ * Freeing a NULL hash or context is safe.
+ */
+void
+cifs_free_hash(struct crypto_shash **shash, struct sdesc **sdesc)
+{
+ kfree(*sdesc);
+ *sdesc = NULL;
+ if (*shash)
+ crypto_free_shash(*shash);
+ *shash = NULL;
+}
--- a/fs/cifs/smb2transport.c
+++ b/fs/cifs/smb2transport.c
@@ -43,76 +43,31 @@
static int
smb2_crypto_shash_allocate(struct TCP_Server_Info *server)
{
- int rc;
- unsigned int size;
-
- if (server->secmech.sdeschmacsha256 != NULL)
- return 0; /* already allocated */
-
- server->secmech.hmacsha256 = crypto_alloc_shash("hmac(sha256)", 0, 0);
- if (IS_ERR(server->secmech.hmacsha256)) {
- cifs_dbg(VFS, "could not allocate crypto hmacsha256\n");
- rc = PTR_ERR(server->secmech.hmacsha256);
- server->secmech.hmacsha256 = NULL;
- return rc;
- }
-
- size = sizeof(struct shash_desc) +
- crypto_shash_descsize(server->secmech.hmacsha256);
- server->secmech.sdeschmacsha256 = kmalloc(size, GFP_KERNEL);
- if (!server->secmech.sdeschmacsha256) {
- crypto_free_shash(server->secmech.hmacsha256);
- server->secmech.hmacsha256 = NULL;
- return -ENOMEM;
- }
- server->secmech.sdeschmacsha256->shash.tfm = server->secmech.hmacsha256;
- server->secmech.sdeschmacsha256->shash.flags = 0x0;
-
- return 0;
+ return cifs_alloc_hash("hmac(sha256)",
+ &server->secmech.hmacsha256,
+ &server->secmech.sdeschmacsha256);
}

static int
smb3_crypto_shash_allocate(struct TCP_Server_Info *server)
{
- unsigned int size;
+ struct cifs_secmech *p = &server->secmech;
int rc;

- if (server->secmech.sdesccmacaes != NULL)
- return 0; /* already allocated */
-
- rc = smb2_crypto_shash_allocate(server);
+ rc = cifs_alloc_hash("hmac(sha256)",
+ &p->hmacsha256,
+ &p->sdeschmacsha256);
if (rc)
- return rc;
-
- server->secmech.cmacaes = crypto_alloc_shash("cmac(aes)", 0, 0);
- if (IS_ERR(server->secmech.cmacaes)) {
- cifs_dbg(VFS, "could not allocate crypto cmac-aes");
- kfree(server->secmech.sdeschmacsha256);
- server->secmech.sdeschmacsha256 = NULL;
- crypto_free_shash(server->secmech.hmacsha256);
- server->secmech.hmacsha256 = NULL;
- rc = PTR_ERR(server->secmech.cmacaes);
- server->secmech.cmacaes = NULL;
- return rc;
- }
+ goto err;

- size = sizeof(struct shash_desc) +
- crypto_shash_descsize(server->secmech.cmacaes);
- server->secmech.sdesccmacaes = kmalloc(size, GFP_KERNEL);
- if (!server->secmech.sdesccmacaes) {
- cifs_dbg(VFS, "%s: Can't alloc cmacaes\n", __func__);
- kfree(server->secmech.sdeschmacsha256);
- server->secmech.sdeschmacsha256 = NULL;
- crypto_free_shash(server->secmech.hmacsha256);
- crypto_free_shash(server->secmech.cmacaes);
- server->secmech.hmacsha256 = NULL;
- server->secmech.cmacaes = NULL;
- return -ENOMEM;
- }
- server->secmech.sdesccmacaes->shash.tfm = server->secmech.cmacaes;
- server->secmech.sdesccmacaes->shash.flags = 0x0;
+ rc = cifs_alloc_hash("cmac(aes)", &p->cmacaes, &p->sdesccmacaes);
+ if (rc)
+ goto err;

return 0;
+err:
+ cifs_free_hash(&p->hmacsha256, &p->sdeschmacsha256);
+ return rc;
}

static struct cifs_ses *
@@ -457,7 +412,7 @@ smb3_calc_signature(struct smb_rqst *rqs
cifs_dbg(VFS, "%s: Could not init cmac aes\n", __func__);
return rc;
}
-
+
rc = __cifs_calc_signature(rqst, server, sigptr,
&server->secmech.sdesccmacaes->shash);

--- a/fs/cifs/smbencrypt.c
+++ b/fs/cifs/smbencrypt.c
@@ -121,25 +121,12 @@ int
mdfour(unsigned char *md4_hash, unsigned char *link_str, int link_len)
{
int rc;
- unsigned int size;
- struct crypto_shash *md4;
- struct sdesc *sdescmd4;
+ struct crypto_shash *md4 = NULL;
+ struct sdesc *sdescmd4 = NULL;

- md4 = crypto_alloc_shash("md4", 0, 0);
- if (IS_ERR(md4)) {
- rc = PTR_ERR(md4);
- cifs_dbg(VFS, "%s: Crypto md4 allocation error %d\n",
- __func__, rc);
- return rc;
- }
- size = sizeof(struct shash_desc) + crypto_shash_descsize(md4);
- sdescmd4 = kmalloc(size, GFP_KERNEL);
- if (!sdescmd4) {
- rc = -ENOMEM;
+ rc = cifs_alloc_hash("md4", &md4, &sdescmd4);
+ if (rc)
goto mdfour_err;
- }
- sdescmd4->shash.tfm = md4;
- sdescmd4->shash.flags = 0x0;

rc = crypto_shash_init(&sdescmd4->shash);
if (rc) {
@@ -156,9 +143,7 @@ mdfour(unsigned char *md4_hash, unsigned
cifs_dbg(VFS, "%s: Could not generate md4 hash\n", __func__);

mdfour_err:
- crypto_free_shash(md4);
- kfree(sdescmd4);
-
+ cifs_free_hash(&md4, &sdescmd4);
return rc;
}


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