[PATCH 4.16 054/196] CIFS: refactor crypto shash/sdesc allocation&free

4.16-stable review patch. If anyone has any objections, please let me know.

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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 @@ -542,4 +542,9 @@ 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; }