Commit 73979060 authored by Greg Kroah-Hartman's avatar Greg Kroah-Hartman

prlimit: do_prlimit needs to have a speculation check

do_prlimit() adds the user-controlled resource value to a pointer that
will subsequently be dereferenced.  In order to help prevent this
codepath from being used as a spectre "gadget" a barrier needs to be
added after checking the range.
Reported-by: default avatarJordy Zomer <jordyzomer@google.com>
Tested-by: default avatarJordy Zomer <jordyzomer@google.com>
Suggested-by: default avatarLinus Torvalds <torvalds@linuxfoundation.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 9be182da
...@@ -1442,6 +1442,8 @@ static int do_prlimit(struct task_struct *tsk, unsigned int resource, ...@@ -1442,6 +1442,8 @@ static int do_prlimit(struct task_struct *tsk, unsigned int resource,
if (resource >= RLIM_NLIMITS) if (resource >= RLIM_NLIMITS)
return -EINVAL; return -EINVAL;
resource = array_index_nospec(resource, RLIM_NLIMITS);
if (new_rlim) { if (new_rlim) {
if (new_rlim->rlim_cur > new_rlim->rlim_max) if (new_rlim->rlim_cur > new_rlim->rlim_max)
return -EINVAL; return -EINVAL;
......
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