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authorJ. Bruce Fields <bfields@redhat.com>2016-03-18 11:31:17 -0400
committerJ. Bruce Fields <bfields@redhat.com>2016-03-22 14:39:35 -0400
commit4b15da44e742871206582f6aa2997b009648f02f (patch)
treee69e230a2db6740a6bc44fd479df3f692429a0c0
parent10c4de10b2624ab9d83bd8e708d39a1867302a6a (diff)
nfsd: better layoutupdate bounds-checking
You could add any multiple of 2^32/PNFS_SCSI_RANGE_SIZE to nr_iomaps and still pass this check. You'd probably still fail the following kcalloc, but best to be paranoid since this is from-the-wire data. Signed-off-by: J. Bruce Fields <bfields@redhat.com>
-rw-r--r--fs/nfsd/blocklayoutxdr.c12
1 files changed, 8 insertions, 4 deletions
diff --git a/fs/nfsd/blocklayoutxdr.c b/fs/nfsd/blocklayoutxdr.c
index ca1883668810..6c3b316f932e 100644
--- a/fs/nfsd/blocklayoutxdr.c
+++ b/fs/nfsd/blocklayoutxdr.c
@@ -105,18 +105,22 @@ nfsd4_block_decode_layoutupdate(__be32 *p, u32 len, struct iomap **iomapp,
u32 block_size)
{
struct iomap *iomaps;
- u32 nr_iomaps, expected, i;
+ u32 nr_iomaps, i;
if (len < sizeof(u32)) {
dprintk("%s: extent array too small: %u\n", __func__, len);
return -EINVAL;
}
+ len -= sizeof(u32);
+ if (len % PNFS_BLOCK_EXTENT_SIZE) {
+ dprintk("%s: extent array invalid: %u\n", __func__, len);
+ return -EINVAL;
+ }
nr_iomaps = be32_to_cpup(p++);
- expected = sizeof(__be32) + nr_iomaps * PNFS_BLOCK_EXTENT_SIZE;
- if (len != expected) {
+ if (nr_iomaps != len / PNFS_BLOCK_EXTENT_SIZE) {
dprintk("%s: extent array size mismatch: %u/%u\n",
- __func__, len, expected);
+ __func__, len, nr_iomaps);
return -EINVAL;
}