Commit 0cbae9e2 authored by Eric W. Biederman's avatar Eric W. Biederman
Browse files

ucounts: Handle wrapping in is_ucounts_overlimit 

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: 21d1c5e3 ("Reimplement RLIMIT_NPROC on top of ucounts")
Link: https://lkml.kernel.org/r/20220216155832.680775-5-ebiederm@xmission.com


Reviewed-by: default avatarShuah Khan <skhan@linuxfoundation.org>
Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
parent c923a8e7

kernel/ucount.c

+2 −1
Original line number Diff line number Diff line
@@ -350,7 +350,8 @@ bool is_ucounts_overlimit(struct ucounts *ucounts, enum ucount_type type, unsign 
	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]);

	}