From bb7081ab93582fd2557160549854200a5fc7b42a Mon Sep 17 00:00:00 2001 From: Eric Paris Date: Wed, 4 Apr 2012 13:46:36 -0400 Subject: [PATCH] SELinux: possible NULL deref in context_struct_to_string It's possible that the caller passed a NULL for scontext. However if this is a defered mapping we might still attempt to call *scontext=kstrdup(). This is bad. Instead just return the len. Signed-off-by: Eric Paris --- security/selinux/ss/services.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c index 1ded0ec7e8c2..9b7e7ed54e7e 100644 --- a/security/selinux/ss/services.c +++ b/security/selinux/ss/services.c @@ -1018,9 +1018,11 @@ static int context_struct_to_string(struct context *context, char **scontext, u3 if (context->len) { *scontext_len = context->len; - *scontext = kstrdup(context->str, GFP_ATOMIC); - if (!(*scontext)) - return -ENOMEM; + if (scontext) { + *scontext = kstrdup(context->str, GFP_ATOMIC); + if (!(*scontext)) + return -ENOMEM; + } return 0; }