From: Eric W. Biederman ebiederm@xmission.com
commit 0cbae9e24fa7d6c6e9f828562f084da82217a0c5 upstream.
While examining is_ucounts_overlimit and reading the various messages I realized that is_ucounts_overlimit fails to deal with counts that may have wrapped.
Being wrapped should be a transitory state for counts and they should never be wrapped for long, but it can happen so handle it.
Cc: stable@vger.kernel.org Fixes: 21d1c5e386bc ("Reimplement RLIMIT_NPROC on top of ucounts") Link: https://lkml.kernel.org/r/20220216155832.680775-5-ebiederm@xmission.com Reviewed-by: Shuah Khan skhan@linuxfoundation.org Signed-off-by: "Eric W. Biederman" ebiederm@xmission.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- kernel/ucount.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/kernel/ucount.c +++ b/kernel/ucount.c @@ -350,7 +350,8 @@ bool is_ucounts_overlimit(struct ucounts if (rlimit > LONG_MAX) max = LONG_MAX; for (iter = ucounts; iter; iter = iter->ns->ucounts) { - if (get_ucounts_value(iter, type) > max) + long val = get_ucounts_value(iter, type); + if (val < 0 || val > max) return true; max = READ_ONCE(iter->ns->ucount_max[type]); }