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[3.16.y-ckt,126/185] crush: fix a bug in tree bucket decode

Message ID 1436951580-15977-127-git-send-email-luis.henriques@canonical.com
State New
Headers show

Commit Message

Luis Henriques July 15, 2015, 9:12 a.m. UTC 
3.16.7-ckt15 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Ilya Dryomov <idryomov@gmail.com>

commit 82cd003a77173c91b9acad8033fb7931dac8d751 upstream.

struct crush_bucket_tree::num_nodes is u8, so ceph_decode_8_safe()
should be used.  -Wconversion catches this, but I guess it went
unnoticed in all the noise it spews.  The actual problem (at least for
common crushmaps) isn't the u32 -> u8 truncation though - it's the
advancement by 4 bytes instead of 1 in the crushmap buffer.

Fixes: http://tracker.ceph.com/issues/2759

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Josh Durgin <jdurgin@redhat.com>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
---
 net/ceph/osdmap.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
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Patch

diff --git a/net/ceph/osdmap.c b/net/ceph/osdmap.c
index c547e46084d3..5740f71b609d 100644
--- a/net/ceph/osdmap.c
+++ b/net/ceph/osdmap.c
@@ -89,7 +89,7 @@  static int crush_decode_tree_bucket(void **p, void *end,
 {
 	int j;
 	dout("crush_decode_tree_bucket %p to %p\n", *p, end);
-	ceph_decode_32_safe(p, end, b->num_nodes, bad);
+	ceph_decode_8_safe(p, end, b->num_nodes, bad);
 	b->node_weights = kcalloc(b->num_nodes, sizeof(u32), GFP_NOFS);
 	if (b->node_weights == NULL)
 		return -ENOMEM;