[PATCH 2/2] block/file-posix: fix wps checking in raw_co_prw

[Sam Li <faithilikerun@gmail.com>]

If the write operation fails and the wps is NULL, then accessing it will
lead to data corruption.

Solving the issue by adding a nullptr checking in get_zones_wp() where
the wps is used.

This issue is found by Peter Maydell using the Coverity Tool (CID
1512459).

Signed-off-by: Sam Li <faithilikerun@gmail.com>
---
 block/file-posix.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/block/file-posix.c b/block/file-posix.c
index 0d9d179a35..620942bf40 100644
--- a/block/file-posix.c
+++ b/block/file-posix.c
@@ -1340,6 +1340,10 @@ static int get_zones_wp(BlockDriverState *bs, int fd, int64_t offset,
     rep_size = sizeof(struct blk_zone_report) + nrz * sizeof(struct blk_zone);
     g_autofree struct blk_zone_report *rep = NULL;
 
+    if (!wps) {
+        return -1;
+    }
+
     rep = g_malloc(rep_size);
     blkz = (struct blk_zone *)(rep + 1);
     while (n < nrz) {
-- 
2.40.1