[PATCH 5.5 17/46] padata: fix uninitialized return value in padata_replace()

[Greg Kroah-Hartman]

From: Daniel Jordan <daniel.m.jordan@xxxxxxxxxx>

[ Upstream commit 41ccdbfd5427bbbf3ed58b16750113b38fad1780 ]

According to Geert's report[0],

  kernel/padata.c: warning: 'err' may be used uninitialized in this
    function [-Wuninitialized]:  => 539:2

Warning is seen only with older compilers on certain archs.  The
runtime effect is potentially returning garbage down the stack when
padata's cpumasks are modified before any pcrypt requests have run.

Simplest fix is to initialize err to the success value.

[0] http://lkml.kernel.org/r/20200210135506.11536-1-geert@xxxxxxxxxxxxxx

Reported-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
Fixes: bbefa1dd6a6d ("crypto: pcrypt - Avoid deadlock by using per-instance padata queues")
Signed-off-by: Daniel Jordan <daniel.m.jordan@xxxxxxxxxx>
Cc: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Cc: Steffen Klassert <steffen.klassert@xxxxxxxxxxx>
Cc: linux-crypto@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 kernel/padata.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/padata.c b/kernel/padata.c
index fda7a7039422d..7bd37dd9ec55b 100644
--- a/kernel/padata.c
+++ b/kernel/padata.c
@@ -516,7 +516,7 @@ static int padata_replace(struct padata_instance *pinst)
 {
 	int notification_mask = 0;
 	struct padata_shell *ps;
-	int err;
+	int err = 0;
 
 	pinst->flags |= PADATA_RESET;
 
-- 
2.20.1