padata: fix uninitialized return value in padata_replace()

[ Upstream commit e9d34c2a76dbbd6dfebf9008fc3354c828ffc977 ]

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@linux-m68k.org

Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Fixes: c7884cb49aa4 ("crypto: pcrypt - Avoid deadlock by using per-instance padata queues")
Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: linux-crypto@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/kernel/padata.c b/kernel/padata.c
index fda7a7039422d8c7781d8420ded685339ce3124e..7bd37dd9ec55bae47a202f3611a1cb9738b9ddd9 100644 (file)
--- 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;