From: Gvozden Neskovic <neskovic@gmail.com>
Date: Thu, 4 Aug 2016 14:23:35 +0000 (+0200)
Subject: zdb: fencepost error at zdb_cb.zcb_embedded_histogram[][]
X-Git-Tag: zfs-0.7.0-rc1~30
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=f0c26069bdf4ec675c840f0932fcfe7d4036d06f;p=zfs

zdb: fencepost error at zdb_cb.zcb_embedded_histogram[][]

Erroneous access detected by gcc UndefinedBehaviorSanitizer:
`zdb.c:2424:7: runtime error: index 112 out of bounds for type 'uint64_t [112]'`

Fix: increase histogram size by 1 to accommodate all possible sizes.

Signed-off-by: Gvozden Neskovic <neskovic@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #4934
Issue #4883
---

diff --git a/cmd/zdb/zdb.c b/cmd/zdb/zdb.c
index 5a196c452..6a076e65d 100644
--- a/cmd/zdb/zdb.c
+++ b/cmd/zdb/zdb.c
@@ -2354,7 +2354,7 @@ typedef struct zdb_cb {
 	uint64_t	zcb_dedup_blocks;
 	uint64_t	zcb_embedded_blocks[NUM_BP_EMBEDDED_TYPES];
 	uint64_t	zcb_embedded_histogram[NUM_BP_EMBEDDED_TYPES]
-	    [BPE_PAYLOAD_SIZE];
+	    [BPE_PAYLOAD_SIZE + 1];
 	uint64_t	zcb_start;
 	uint64_t	zcb_lastprint;
 	uint64_t	zcb_totalasize;