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| author | J. Bruce Fields <bfields@redhat.com> | 2012-12-04 18:25:10 -0500 |
|---|---|---|
| committer | J. Bruce Fields <bfields@redhat.com> | 2012-12-17 21:55:21 -0500 |
| commit | d5f50b0c290431c65377c4afa1c764e2c3fe5305 (patch) | |
| tree | 9d08b4a0a8a1aed35de43ec55cd0a94fbab2e015 | |
| parent | 9b3234b9220aae5387b60bc35a424ab6748b2b59 (diff) | |
| download | op-kernel-dev-d5f50b0c290431c65377c4afa1c764e2c3fe5305.zip op-kernel-dev-d5f50b0c290431c65377c4afa1c764e2c3fe5305.tar.gz | |
nfsd4: fix oops on unusual readlike compound
If the argument and reply together exceed the maximum payload size, then
a reply with a read-like operation can overlow the rq_pages array.
Cc: stable@kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
| -rw-r--r-- | fs/nfsd/nfs4xdr.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c index 3bf8a9d..d7a3be5 100644 --- a/fs/nfsd/nfs4xdr.c +++ b/fs/nfsd/nfs4xdr.c @@ -2925,11 +2925,16 @@ nfsd4_encode_read(struct nfsd4_compoundres *resp, __be32 nfserr, len = maxcount; v = 0; while (len > 0) { - pn = resp->rqstp->rq_resused++; + pn = resp->rqstp->rq_resused; + if (!resp->rqstp->rq_respages[pn]) { /* ran out of pages */ + maxcount -= len; + break; + } resp->rqstp->rq_vec[v].iov_base = page_address(resp->rqstp->rq_respages[pn]); resp->rqstp->rq_vec[v].iov_len = len < PAGE_SIZE ? len : PAGE_SIZE; + resp->rqstp->rq_resused++; v++; len -= PAGE_SIZE; } @@ -2975,6 +2980,8 @@ nfsd4_encode_readlink(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd return nfserr; if (resp->xbuf->page_len) return nfserr_resource; + if (!resp->rqstp->rq_respages[resp->rqstp->rq_resused]) + return nfserr_resource; page = page_address(resp->rqstp->rq_respages[resp->rqstp->rq_resused++]); @@ -3024,6 +3031,8 @@ nfsd4_encode_readdir(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4 return nfserr; if (resp->xbuf->page_len) return nfserr_resource; + if (!resp->rqstp->rq_respages[resp->rqstp->rq_resused]) + return nfserr_resource; RESERVE_SPACE(NFS4_VERIFIER_SIZE); savep = p; |
