diff options
| author | Eric Biggers <ebiggers@kernel.org> | 2025-08-04 22:47:00 +0000 |
|---|---|---|
| committer | Chuck Lever <chuck.lever@oracle.com> | 2025-09-21 19:24:50 -0400 |
| commit | 9ebcd022a34388bd3c37c6a11c1a9d49d5394eb2 (patch) | |
| tree | e2634c2a9bb7b1e9cd4374744adb2ee427d6b66a | |
| parent | 17695d72d0b192bb471a699483dd6c6c2576c57d (diff) | |
nfsd: Eliminate an allocation in nfs4_make_rec_clidname()
Since MD5 digests are fixed-size, make nfs4_make_rec_clidname() store
the digest in a stack buffer instead of a dynamically allocated buffer.
Use MD5_DIGEST_SIZE instead of a hard-coded value, both in
nfs4_make_rec_clidname() and in the definition of HEXDIR_LEN.
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
| -rw-r--r-- | fs/nfsd/nfs4recover.c | 15 | ||||
| -rw-r--r-- | fs/nfsd/state.h | 4 |
2 files changed, 7 insertions, 12 deletions
diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c index 54f5e5392ef9..e2b9472e5c78 100644 --- a/fs/nfsd/nfs4recover.c +++ b/fs/nfsd/nfs4recover.c @@ -95,7 +95,7 @@ nfs4_reset_creds(const struct cred *original) static int nfs4_make_rec_clidname(char dname[HEXDIR_LEN], const struct xdr_netobj *clname) { - struct xdr_netobj cksum; + u8 digest[MD5_DIGEST_SIZE]; struct crypto_shash *tfm; int status; @@ -107,23 +107,16 @@ nfs4_make_rec_clidname(char dname[HEXDIR_LEN], const struct xdr_netobj *clname) goto out_no_tfm; } - cksum.len = crypto_shash_digestsize(tfm); - cksum.data = kmalloc(cksum.len, GFP_KERNEL); - if (cksum.data == NULL) { - status = -ENOMEM; - goto out; - } - status = crypto_shash_tfm_digest(tfm, clname->data, clname->len, - cksum.data); + digest); if (status) goto out; - sprintf(dname, "%*phN", 16, cksum.data); + static_assert(HEXDIR_LEN == 2 * MD5_DIGEST_SIZE + 1); + sprintf(dname, "%*phN", MD5_DIGEST_SIZE, digest); status = 0; out: - kfree(cksum.data); crypto_free_shash(tfm); out_no_tfm: return status; diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h index b6ac0f37e9cd..1e736f402426 100644 --- a/fs/nfsd/state.h +++ b/fs/nfsd/state.h @@ -35,6 +35,7 @@ #ifndef _NFSD4_STATE_H #define _NFSD4_STATE_H +#include <crypto/md5.h> #include <linux/idr.h> #include <linux/refcount.h> #include <linux/sunrpc/svc_xprt.h> @@ -391,7 +392,8 @@ struct nfsd4_sessionid { u32 reserved; }; -#define HEXDIR_LEN 33 /* hex version of 16 byte md5 of cl_name plus '\0' */ +/* Length of MD5 digest as hex, plus terminating '\0' */ +#define HEXDIR_LEN (2 * MD5_DIGEST_SIZE + 1) /* * State Meaning Where set |