[PATCH] kobject_uevent: Fix OOB access within zap_modalias_env()

[Zijun Hu]

zap_modalias_env() wrongly calculates size of memory block
to move, so maybe cause OOB memory access issue, fixed by
correcting size to memmove.

Fixes: 9b3fa47d4a76 ("kobject: fix suppressing modalias in uevents delivered over netlink")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Zijun Hu <quic_zijuhu@xxxxxxxxxxx>
---
 lib/kobject_uevent.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c
index 03b427e2707e..f153b4f9d4d9 100644
--- a/lib/kobject_uevent.c
+++ b/lib/kobject_uevent.c
@@ -434,7 +434,7 @@ static void zap_modalias_env(struct kobj_uevent_env *env)
 
 		if (i != env->envp_idx - 1) {
 			memmove(env->envp[i], env->envp[i + 1],
-				env->buflen - len);
+				env->buf + env->buflen - env->envp[i + 1]);
 
 			for (j = i; j < env->envp_idx - 1; j++)
 				env->envp[j] = env->envp[j + 1] - len;
-- 
2.7.4