2016-07-14 04:02:05

by Kinglong Mee

[permalink] [raw]
Subject: [PATCH] nfs/blocklayout: Check max uuids and devices before decoding

Avoid nfs return uuids/devices larger than maximum.

Signed-off-by: Kinglong Mee <[email protected]>
---
fs/nfs/blocklayout/dev.c | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/fs/nfs/blocklayout/dev.c b/fs/nfs/blocklayout/dev.c
index 3021015..6d71b67 100644
--- a/fs/nfs/blocklayout/dev.c
+++ b/fs/nfs/blocklayout/dev.c
@@ -65,8 +65,8 @@ nfs4_block_decode_volume(struct xdr_stream *xdr, struct pnfs_block_volume *b)
if (!p)
return -EIO;
b->simple.nr_sigs = be32_to_cpup(p++);
- if (!b->simple.nr_sigs) {
- dprintk("no signature\n");
+ if (!b->simple.nr_sigs || b->simple.nr_sigs > PNFS_BLOCK_MAX_UUIDS) {
+ dprintk("Bad signature count: %d\n", b->simple.nr_sigs);
return -EIO;
}

@@ -105,7 +105,12 @@ nfs4_block_decode_volume(struct xdr_stream *xdr, struct pnfs_block_volume *b)
p = xdr_inline_decode(xdr, 4);
if (!p)
return -EIO;
+
b->concat.volumes_count = be32_to_cpup(p++);
+ if (b->concat.volumes_count > PNFS_BLOCK_MAX_DEVICES) {
+ dprintk("Too many volumes: %d\n", b->concat.volumes_count);
+ return -EIO;
+ }

p = xdr_inline_decode(xdr, b->concat.volumes_count * 4);
if (!p)
@@ -117,8 +122,13 @@ nfs4_block_decode_volume(struct xdr_stream *xdr, struct pnfs_block_volume *b)
p = xdr_inline_decode(xdr, 8 + 4);
if (!p)
return -EIO;
+
p = xdr_decode_hyper(p, &b->stripe.chunk_size);
b->stripe.volumes_count = be32_to_cpup(p++);
+ if (b->stripe.volumes_count > PNFS_BLOCK_MAX_DEVICES) {
+ dprintk("Too many volumes: %d\n", b->stripe.volumes_count);
+ return -EIO;
+ }

p = xdr_inline_decode(xdr, b->stripe.volumes_count * 4);
if (!p)
--
2.7.4