Messages in this thread | | | Subject | Re: [PATCH] landlock: Initialize kernel stack variables properly | From | Mickaël Salaün <> | Date | Wed, 3 Nov 2021 13:17:19 +0100 |
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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.
> /* 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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