5.10-stable review patch. If anyone has any objections, please let me know.
------------------
From: Chuck Lever chuck.lever@oracle.com
[ Upstream commit 081d53fe0b43c47c36d1832b759bf14edde9cdbb ]
Because the fattr4 is now managed in an xdr_stream, all that is needed is to store the initial position of the stream before decoding the attribute list. Then the actual length of the list is computed using the final stream position, after decoding is complete.
No behavior change is expected.
Signed-off-by: Chuck Lever chuck.lever@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/nfsd/nfs4xdr.c | 34 +++++++++++----------------------- 1 file changed, 11 insertions(+), 23 deletions(-)
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c index 8251b905d5479..de5ac334cb8ab 100644 --- a/fs/nfsd/nfs4xdr.c +++ b/fs/nfsd/nfs4xdr.c @@ -250,7 +250,8 @@ nfsd4_decode_fattr(struct nfsd4_compoundargs *argp, u32 *bmval, struct iattr *iattr, struct nfs4_acl **acl, struct xdr_netobj *label, int *umask) { - int expected_len, len = 0; + unsigned int starting_pos; + u32 attrlist4_count; u32 dummy32; char *buf;
@@ -267,12 +268,12 @@ nfsd4_decode_fattr(struct nfsd4_compoundargs *argp, u32 *bmval, return nfserr_attrnotsupp; }
- READ_BUF(4); - expected_len = be32_to_cpup(p++); + if (xdr_stream_decode_u32(argp->xdr, &attrlist4_count) < 0) + return nfserr_bad_xdr; + starting_pos = xdr_stream_pos(argp->xdr);
if (bmval[0] & FATTR4_WORD0_SIZE) { READ_BUF(8); - len += 8; p = xdr_decode_hyper(p, &iattr->ia_size); iattr->ia_valid |= ATTR_SIZE; } @@ -280,7 +281,7 @@ nfsd4_decode_fattr(struct nfsd4_compoundargs *argp, u32 *bmval, u32 nace; struct nfs4_ace *ace;
- READ_BUF(4); len += 4; + READ_BUF(4); nace = be32_to_cpup(p++);
if (nace > xdr_stream_remaining(argp->xdr) / sizeof(struct nfs4_ace)) @@ -297,13 +298,12 @@ nfsd4_decode_fattr(struct nfsd4_compoundargs *argp, u32 *bmval,
(*acl)->naces = nace; for (ace = (*acl)->aces; ace < (*acl)->aces + nace; ace++) { - READ_BUF(16); len += 16; + READ_BUF(16); ace->type = be32_to_cpup(p++); ace->flag = be32_to_cpup(p++); ace->access_mask = be32_to_cpup(p++); dummy32 = be32_to_cpup(p++); READ_BUF(dummy32); - len += XDR_QUADLEN(dummy32) << 2; READMEM(buf, dummy32); ace->whotype = nfs4_acl_get_whotype(buf, dummy32); status = nfs_ok; @@ -322,17 +322,14 @@ nfsd4_decode_fattr(struct nfsd4_compoundargs *argp, u32 *bmval, *acl = NULL; if (bmval[1] & FATTR4_WORD1_MODE) { READ_BUF(4); - len += 4; iattr->ia_mode = be32_to_cpup(p++); iattr->ia_mode &= (S_IFMT | S_IALLUGO); iattr->ia_valid |= ATTR_MODE; } if (bmval[1] & FATTR4_WORD1_OWNER) { READ_BUF(4); - len += 4; dummy32 = be32_to_cpup(p++); READ_BUF(dummy32); - len += (XDR_QUADLEN(dummy32) << 2); READMEM(buf, dummy32); if ((status = nfsd_map_name_to_uid(argp->rqstp, buf, dummy32, &iattr->ia_uid))) return status; @@ -340,10 +337,8 @@ nfsd4_decode_fattr(struct nfsd4_compoundargs *argp, u32 *bmval, } if (bmval[1] & FATTR4_WORD1_OWNER_GROUP) { READ_BUF(4); - len += 4; dummy32 = be32_to_cpup(p++); READ_BUF(dummy32); - len += (XDR_QUADLEN(dummy32) << 2); READMEM(buf, dummy32); if ((status = nfsd_map_name_to_gid(argp->rqstp, buf, dummy32, &iattr->ia_gid))) return status; @@ -351,11 +346,9 @@ nfsd4_decode_fattr(struct nfsd4_compoundargs *argp, u32 *bmval, } if (bmval[1] & FATTR4_WORD1_TIME_ACCESS_SET) { READ_BUF(4); - len += 4; dummy32 = be32_to_cpup(p++); switch (dummy32) { case NFS4_SET_TO_CLIENT_TIME: - len += 12; status = nfsd4_decode_time(argp, &iattr->ia_atime); if (status) return status; @@ -370,11 +363,9 @@ nfsd4_decode_fattr(struct nfsd4_compoundargs *argp, u32 *bmval, } if (bmval[1] & FATTR4_WORD1_TIME_MODIFY_SET) { READ_BUF(4); - len += 4; dummy32 = be32_to_cpup(p++); switch (dummy32) { case NFS4_SET_TO_CLIENT_TIME: - len += 12; status = nfsd4_decode_time(argp, &iattr->ia_mtime); if (status) return status; @@ -392,18 +383,14 @@ nfsd4_decode_fattr(struct nfsd4_compoundargs *argp, u32 *bmval, if (IS_ENABLED(CONFIG_NFSD_V4_SECURITY_LABEL) && bmval[2] & FATTR4_WORD2_SECURITY_LABEL) { READ_BUF(4); - len += 4; dummy32 = be32_to_cpup(p++); /* lfs: we don't use it */ READ_BUF(4); - len += 4; dummy32 = be32_to_cpup(p++); /* pi: we don't use it either */ READ_BUF(4); - len += 4; dummy32 = be32_to_cpup(p++); READ_BUF(dummy32); if (dummy32 > NFS4_MAXLABELLEN) return nfserr_badlabel; - len += (XDR_QUADLEN(dummy32) << 2); READMEM(buf, dummy32); label->len = dummy32; label->data = svcxdr_dupstr(argp, buf, dummy32); @@ -414,15 +401,16 @@ nfsd4_decode_fattr(struct nfsd4_compoundargs *argp, u32 *bmval, if (!umask) goto xdr_error; READ_BUF(8); - len += 8; dummy32 = be32_to_cpup(p++); iattr->ia_mode = dummy32 & (S_IFMT | S_IALLUGO); dummy32 = be32_to_cpup(p++); *umask = dummy32 & S_IRWXUGO; iattr->ia_valid |= ATTR_MODE; } - if (len != expected_len) - goto xdr_error; + + /* request sanity: did attrlist4 contain the expected number of words? */ + if (attrlist4_count != xdr_stream_pos(argp->xdr) - starting_pos) + return nfserr_bad_xdr;
DECODE_TAIL; }