[patch 7/8] dm verity fec: Check result of init_rs()

[Thomas Gleixner]

The allocation of the reed solomon control structure can fail, but
fec_alloc_bufs() ignores that and subsequent operations in dm verity use
the potential NULL pointer unconditionally.

Add a proper check and abort if init_rs() fails.

Signed-off-by: Thomas Gleixner <t...@linutronix.de>
---
 drivers/md/dm-verity-fec.c |    7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

--- a/drivers/md/dm-verity-fec.c
+++ b/drivers/md/dm-verity-fec.c
@@ -308,8 +308,13 @@ static int fec_alloc_bufs(struct dm_veri
 {
        unsigned n;
 
-       if (!fio->rs)
+       if (!fio->rs) {
                fio->rs = mempool_alloc(v->fec->rs_pool, GFP_NOIO);
+               if (!fio->rs) {
+                       DMERR("failed to allocate RS control structure");
+                       return -ENOMEM;
+               }
+       }
 
        fec_for_each_prealloc_buffer(n) {
                if (fio->bufs[n])