staging: vchiq_arm: Avoid NULL ptr deref in vchiq_dump_platform_instances

BugLink: https://bugs.launchpad.net/bugs/1969107
[ Upstream commit aa899e686d442c63d50f4d369cc02dbbf0941cb0 ]

vchiq_get_state() can return a NULL pointer. So handle this cases and
avoid a NULL pointer derefence in vchiq_dump_platform_instances.

Reviewed-by: Nicolas Saenz Julienne <nsaenz@kernel.org>
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Link: https://lore.kernel.org/r/1642968143-19281-17-git-send-email-stefan.wahren@i2se.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
(cherry picked from commit 176df12b38c70b0a45e6392a0ee5bc83489dfc29)
Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>

diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
index ea9a53bdb417416d5112d35c51a8df31f2eabd3f..099359fc0115271afd4c239fa1f0004d94ab4dbe 100644 (file)
--- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
+++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
@@ -1189,6 +1189,9 @@ int vchiq_dump_platform_instances(void *dump_context)
        int len;
        int i;
 
+       if (!state)
+               return -ENOTCONN;
+
        /*
         * There is no list of instances, so instead scan all services,
         * marking those that have been dumped.