From: Greg Kroah-Hartman gregkh@linuxfoundation.org
stable inclusion from stable-v4.19.271 commit d3ee91e50a6b3c5a45398e3dcb912a8a264f575c category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I6DPF8 CVE: NA
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commit 739790605705ddcf18f21782b9c99ad7d53a8c11 upstream.
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: Jordy Zomer jordyzomer@google.com Tested-by: Jordy Zomer jordyzomer@google.com Suggested-by: Linus Torvalds torvalds@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Yongqiang Liu liuyongqiang13@huawei.com --- kernel/sys.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/kernel/sys.c b/kernel/sys.c index faef6e6b635f..b088b71732b7 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -1530,6 +1530,8 @@ int do_prlimit(struct task_struct *tsk, unsigned int resource,
if (resource >= RLIM_NLIMITS) return -EINVAL; + resource = array_index_nospec(resource, RLIM_NLIMITS); + if (new_rlim) { if (new_rlim->rlim_cur > new_rlim->rlim_max) return -EINVAL;