[PATCH 03/12] pseries/plpks: validate input to plpks_signed_update_var()

[Srish Srinivasan]

plpks_signed_update_var() dereferences the supplied PLPKS variable pointer
without validating it. A NULL argument could therefore result in a NULL
pointer dereference.

Reject a NULL pointer argument with -EINVAL.

Fixes: 899d9b8fee66 ("powerpc/pseries: Implement signed update for PLPKS objects")
Cc: stable@xxxxxxxxxxxxxxx # 6.3
Signed-off-by: Srish Srinivasan <ssrish@xxxxxxxxxxxxx>
Tested-by: R Nageswara Sastry <rnsastry@xxxxxxxxxxxxx>
---
 arch/powerpc/platforms/pseries/plpks.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/powerpc/platforms/pseries/plpks.c b/arch/powerpc/platforms/pseries/plpks.c
index ccf5765a907b..e3ae2cd78247 100644
--- a/arch/powerpc/platforms/pseries/plpks.c
+++ b/arch/powerpc/platforms/pseries/plpks.c
@@ -637,6 +637,9 @@ int plpks_signed_update_var(struct plpks_var *var, u64 flags)
 	u64 continuetoken = 0;
 	u64 timeout = 0;
 
+	if (!var)
+		return -EINVAL;
+
 	if (!var->data || var->datalen <= 0 || var->namelen > PLPKS_MAX_NAME_SIZE)
 		return -EINVAL;
 
-- 
2.52.0