diff options
Diffstat (limited to 'freed-ora/tags/f27/4.15.9-300.fc27.gnu/CVE-2017-7645.patch')
| -rw-r--r-- | freed-ora/tags/f27/4.15.9-300.fc27.gnu/CVE-2017-7645.patch | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/freed-ora/tags/f27/4.15.9-300.fc27.gnu/CVE-2017-7645.patch b/freed-ora/tags/f27/4.15.9-300.fc27.gnu/CVE-2017-7645.patch new file mode 100644 index 000000000..0be019cc3 --- /dev/null +++ b/freed-ora/tags/f27/4.15.9-300.fc27.gnu/CVE-2017-7645.patch @@ -0,0 +1,180 @@ +From: "J. Bruce Fields" <bfields@redhat.com> +Date: 2017-04-14 15:04:40 +Subject: [PATCH] nfsd: check for oversized NFSv2/v3 arguments + +A client can append random data to the end of an NFSv2 or NFSv3 RPC call +without our complaining; we'll just stop parsing at the end of the +expected data and ignore the rest. + +Encoded arguments and replies are stored together in an array of pages, +and if a call is too large it could leave inadequate space for the +reply. This is normally OK because NFS RPC's typically have either +short arguments and long replies (like READ) or long arguments and short +replies (like WRITE). But a client that sends an incorrectly long reply +can violate those assumptions. This was observed to cause crashes. + +So, insist that the argument not be any longer than we expect. + +Also, several operations increment rq_next_page in the decode routine +before checking the argument size, which can leave rq_next_page pointing +well past the end of the page array, causing trouble later in +svc_free_pages. + +As followup we may also want to rewrite the encoding routines to check +more carefully that they aren't running off the end of the page array. + +Reported-by: Tuomas Haanpää <thaan@synopsys.com> +Reported-by: Ari Kauppi <ari@synopsys.com> +Cc: stable@vger.kernel.org +Signed-off-by: J. Bruce Fields <bfields@redhat.com> +--- + fs/nfsd/nfs3xdr.c | 23 +++++++++++++++++------ + fs/nfsd/nfsxdr.c | 13 ++++++++++--- + include/linux/sunrpc/svc.h | 3 +-- + 3 files changed, 28 insertions(+), 11 deletions(-) + +diff --git a/fs/nfsd/nfs3xdr.c b/fs/nfsd/nfs3xdr.c +index dba2ff8eaa68..be66bcadfaea 100644 +--- a/fs/nfsd/nfs3xdr.c ++++ b/fs/nfsd/nfs3xdr.c +@@ -334,8 +334,11 @@ nfs3svc_decode_readargs(struct svc_rqst *rqstp, __be32 *p, + if (!p) + return 0; + p = xdr_decode_hyper(p, &args->offset); +- + args->count = ntohl(*p++); ++ ++ if (!xdr_argsize_check(rqstp, p)) ++ return 0; ++ + len = min(args->count, max_blocksize); + + /* set up the kvec */ +@@ -349,7 +352,7 @@ nfs3svc_decode_readargs(struct svc_rqst *rqstp, __be32 *p, + v++; + } + args->vlen = v; +- return xdr_argsize_check(rqstp, p); ++ return 1; + } + + int +@@ -536,9 +539,11 @@ nfs3svc_decode_readlinkargs(struct svc_rqst *rqstp, __be32 *p, + p = decode_fh(p, &args->fh); + if (!p) + return 0; ++ if (!xdr_argsize_check(rqstp, p)) ++ return 0; + args->buffer = page_address(*(rqstp->rq_next_page++)); + +- return xdr_argsize_check(rqstp, p); ++ return 1; + } + + int +@@ -564,10 +569,14 @@ nfs3svc_decode_readdirargs(struct svc_rqst *rqstp, __be32 *p, + args->verf = p; p += 2; + args->dircount = ~0; + args->count = ntohl(*p++); ++ ++ if (!xdr_argsize_check(rqstp, p)) ++ return 0; ++ + args->count = min_t(u32, args->count, PAGE_SIZE); + args->buffer = page_address(*(rqstp->rq_next_page++)); + +- return xdr_argsize_check(rqstp, p); ++ return 1; + } + + int +@@ -585,6 +594,9 @@ nfs3svc_decode_readdirplusargs(struct svc_rqst *rqstp, __be32 *p, + args->dircount = ntohl(*p++); + args->count = ntohl(*p++); + ++ if (!xdr_argsize_check(rqstp, p)) ++ return 0; ++ + len = args->count = min(args->count, max_blocksize); + while (len > 0) { + struct page *p = *(rqstp->rq_next_page++); +@@ -592,8 +604,7 @@ nfs3svc_decode_readdirplusargs(struct svc_rqst *rqstp, __be32 *p, + args->buffer = page_address(p); + len -= PAGE_SIZE; + } +- +- return xdr_argsize_check(rqstp, p); ++ return 1; + } + + int +diff --git a/fs/nfsd/nfsxdr.c b/fs/nfsd/nfsxdr.c +index 41b468a6a90f..79268369f7b3 100644 +--- a/fs/nfsd/nfsxdr.c ++++ b/fs/nfsd/nfsxdr.c +@@ -257,6 +257,9 @@ nfssvc_decode_readargs(struct svc_rqst *rqstp, __be32 *p, + len = args->count = ntohl(*p++); + p++; /* totalcount - unused */ + ++ if (!xdr_argsize_check(rqstp, p)) ++ return 0; ++ + len = min_t(unsigned int, len, NFSSVC_MAXBLKSIZE_V2); + + /* set up somewhere to store response. +@@ -272,7 +275,7 @@ nfssvc_decode_readargs(struct svc_rqst *rqstp, __be32 *p, + v++; + } + args->vlen = v; +- return xdr_argsize_check(rqstp, p); ++ return 1; + } + + int +@@ -360,9 +363,11 @@ nfssvc_decode_readlinkargs(struct svc_rqst *rqstp, __be32 *p, struct nfsd_readli + p = decode_fh(p, &args->fh); + if (!p) + return 0; ++ if (!xdr_argsize_check(rqstp, p)) ++ return 0; + args->buffer = page_address(*(rqstp->rq_next_page++)); + +- return xdr_argsize_check(rqstp, p); ++ return 1; + } + + int +@@ -400,9 +405,11 @@ nfssvc_decode_readdirargs(struct svc_rqst *rqstp, __be32 *p, + args->cookie = ntohl(*p++); + args->count = ntohl(*p++); + args->count = min_t(u32, args->count, PAGE_SIZE); ++ if (!xdr_argsize_check(rqstp, p)) ++ return 0; + args->buffer = page_address(*(rqstp->rq_next_page++)); + +- return xdr_argsize_check(rqstp, p); ++ return 1; + } + + /* +diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h +index e770abeed32d..6ef19cf658b4 100644 +--- a/include/linux/sunrpc/svc.h ++++ b/include/linux/sunrpc/svc.h +@@ -336,8 +336,7 @@ xdr_argsize_check(struct svc_rqst *rqstp, __be32 *p) + { + char *cp = (char *)p; + struct kvec *vec = &rqstp->rq_arg.head[0]; +- return cp >= (char*)vec->iov_base +- && cp <= (char*)vec->iov_base + vec->iov_len; ++ return cp == (char *)vec->iov_base + vec->iov_len; + } + + static inline int +-- +2.9.3 + +-- +To unsubscribe from this list: send the line "unsubscribe linux-nfs" in +the body of a message to majordomo@vger.kernel.org +More majordomo info at http://vger.kernel.org/majordomo-info.html |
