From mboxrd@z Thu Jan 1 00:00:00 1970 From: Haitao Huang Subject: [PATCH v3 18/28] cgroup/misc: Fix an overflow Date: Wed, 12 Jul 2023 16:01:52 -0700 Message-ID: <20230712230202.47929-19-haitao.huang@linux.intel.com> References: <20230712230202.47929-1-haitao.huang@linux.intel.com> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1689202937; x=1720738937; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=gtPme0IuXCAV4jbp0xb73aBMQFtTiscdTlcYYwDyGg8=; b=LU/fwLB0h47yZrs3fFKLbojxHgRpYrQ6iIvzDpxHqSnhwm5C1Bb8lLs3 ZZ6eclaF+n5kv3WCCBcwpdZ6Bbk/iqdD9EfLa77GTJO+z9mNYI+HXbDjw Y85VOTZTDQegwUXEfgzDNOdIbhgoO/gOSGk9uKinxNZv1aKMEMqUMzaWh hGKMsgb9vB9RX1YA2Nsepz7A34ZIoWfQXbWMU+jLkSuXjDid1mudOwH+y JVcIWZvhc9ffHBl1yLv1/kt7JjkPJ6DpegqdUBLCCM/KmrxWFJNudHqC9 o+PNaBrus11gnGpxuGjD4b4J7cOq/j/q9dX6kGwTfYHJNt7hAV1lC+qxO A==; In-Reply-To: <20230712230202.47929-1-haitao.huang-VuQAYsv1563Yd54FQh9/CA@public.gmane.org> List-ID: Content-Type: text/plain; charset="us-ascii" To: jarkko-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, dave.hansen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org, tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-sgx-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Zefan Li , Johannes Weiner Cc: kai.huang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, reinette.chatre-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, zhiquan1.li-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, kristen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org Overflow may happen in misc_cg_try_charge if new_usage becomes above INT_MAX, for example, on platforms with large SGX EPC sizes. Change type of new_usage to long from int and check overflow. Signed-off-by: Haitao Huang --- kernel/cgroup/misc.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/kernel/cgroup/misc.c b/kernel/cgroup/misc.c index fe3e8a0eb7ed..ff9f900981a3 100644 --- a/kernel/cgroup/misc.c +++ b/kernel/cgroup/misc.c @@ -143,7 +143,7 @@ int misc_cg_try_charge(enum misc_res_type type, struct misc_cg *cg, struct misc_cg *i, *j; int ret; struct misc_res *res; - int new_usage; + long new_usage; if (!(valid_type(type) && cg && READ_ONCE(misc_res_capacity[type]))) return -EINVAL; @@ -153,10 +153,10 @@ int misc_cg_try_charge(enum misc_res_type type, struct misc_cg *cg, for (i = cg; i; i = parent_misc(i)) { res = &i->res[type]; - new_usage = atomic_long_add_return(amount, &res->usage); if (new_usage > READ_ONCE(res->max) || - new_usage > READ_ONCE(misc_res_capacity[type])) { + new_usage > READ_ONCE(misc_res_capacity[type]) || + new_usage < 0) { ret = -EBUSY; goto err_charge; } -- 2.25.1