Messages in this thread | | | From | Austin Kim <> | Date | Thu, 4 Nov 2021 20:41:10 +0900 | Subject | Re: [PATCH] landlock: Initialize kernel stack variables properly |
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2021년 11월 3일 (수) 오후 9:14, Mickaël Salaün <mic@digikod.net>님이 작성: > > Hi Austin, > > On 03/11/2021 08:14, Austin Kim wrote: > > In case kernel stack variables are not initialized properly, there might > > be a little chance of kernel information disclosure. So it is better for > > kernel stack variables to be initialized with null characters. > > > > Signed-off-by: Austin Kim <austindh.kim@gmail.com> > > --- > > security/landlock/syscalls.c | 2 ++ > > 1 file changed, 2 insertions(+) > > > > diff --git a/security/landlock/syscalls.c b/security/landlock/syscalls.c > > index 32396962f04d..50a6f7091428 100644 > > --- a/security/landlock/syscalls.c > > +++ b/security/landlock/syscalls.c > > @@ -320,6 +320,8 @@ SYSCALL_DEFINE4(landlock_add_rule, > > if (rule_type != LANDLOCK_RULE_PATH_BENEATH) > > return -EINVAL; > > > > + memset(&path_beneath_attr, 0, sizeof(path_beneath_attr)); > > + > > This memset is already done with the copy_from_user() call just below. >
It seems that memset() is done inside copy_from_user(). Thanks for feedback.
BR, Austin Kim
> > /* Copies raw user space buffer, only one type for now. */ > > res = copy_from_user(&path_beneath_attr, rule_attr, > > sizeof(path_beneath_attr)); > >
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