From: Haitao Huang <haitao.huang@linux.intel.com>
To: tj@kernel.org, jarkko@kernel.org, dave.hansen@linux.intel.com,
linux-kernel@vger.kernel.org, linux-sgx@vger.kernel.org,
cgroups@vger.kernel.org, Zefan Li <lizefan.x@bytedance.com>,
Johannes Weiner <hannes@cmpxchg.org>
Cc: vipinsh@google.com, kai.huang@intel.com,
reinette.chatre@intel.com, zhiquan1.li@intel.com,
kristen@linux.intel.com
Subject: [PATCH 1/2] cgroup/misc: Fix an overflow
Date: Mon, 17 Jul 2023 18:08:44 -0700 [thread overview]
Message-ID: <20230718010845.35197-1-haitao.huang@linux.intel.com> (raw)
In-Reply-To: <ZLWmdBfcuPUBtk1K@slm.duckdns.org>
The variable 'new_usage' in misc_cg_try_charge() may overflow if it
becomes above INT_MAX. This was observed when I implement the new SGX
EPC cgroup[1] as a misc cgroup and test on a platform with large SGX EPC
sizes.
Change type of new_usage to long from int and check overflow.
Fixes: a72232eabdfc ("cgroup: Add misc cgroup controller")
Signed-off-by: Haitao Huang <haitao.huang@linux.intel.com>
[1] https://lore.kernel.org/linux-sgx/20230712230202.47929-1-haitao.huang@linux.intel.com/
---
kernel/cgroup/misc.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/kernel/cgroup/misc.c b/kernel/cgroup/misc.c
index fe3e8a0eb7ed..b127607837c6 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;
@@ -156,7 +156,8 @@ int misc_cg_try_charge(enum misc_res_type type, struct misc_cg *cg,
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
next prev parent reply other threads:[~2023-07-18 1:09 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-17 18:47 [PATCH] cgroup/misc: Fix an overflow Haitao Huang
2023-07-17 18:51 ` Tejun Heo
2023-07-17 18:55 ` Jarkko Sakkinen
2023-07-17 18:57 ` Tejun Heo
2023-07-17 19:01 ` Haitao Huang
2023-07-17 20:19 ` Haitao Huang
2023-07-17 20:37 ` Tejun Heo
2023-07-18 1:08 ` Haitao Huang [this message]
2023-07-18 1:08 ` [PATCH 2/2] cgroup/misc: Change counters to be explicit 64bit types Haitao Huang
2023-07-18 22:52 ` Tejun Heo
2023-07-21 2:48 ` Haitao Huang
2023-07-21 12:02 ` [PATCH] cgroup/misc: Store atomic64_t reads to u64 Haitao Huang
2023-07-21 18:10 ` Tejun Heo
2023-07-18 1:11 ` [PATCH] cgroup/misc: Fix an overflow Haitao Huang
2023-07-18 15:41 ` Jarkko Sakkinen
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