From: Zev Weiss <zev@bewilderbeest.net>
To: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>
Cc: openbmc@lists.ozlabs.org,
Jason M Biils <jason.m.bills@linux.intel.com>,
James Feist <james.feist@linux.intel.com>
Subject: Re: [PATCH 1/2] peci: fix error-handling in peci_dev_ioctl()
Date: Mon, 28 Sep 2020 14:09:53 -0500 [thread overview]
Message-ID: <20200928190953.3wnfph2pwysrvequ@hatter.bewilderbeest.net> (raw)
In-Reply-To: <d64f8001-a13e-45e5-53cc-96da50614ec7@linux.intel.com>
On Mon, Sep 28, 2020 at 02:03:12PM CDT, Jae Hyun Yoo wrote:
>Hello Zev,
>
>On 9/26/2020 2:27 PM, Zev Weiss wrote:
>>peci_get_xfer_msg() returns NULL on failure, not an ERR_PTR. Also
>>avoid calling kfree() on an ERR_PTR.
>>
>>Signed-off-by: Zev Weiss <zev@bewilderbeest.net>
>>---
>> drivers/peci/peci-dev.c | 7 ++++---
>> 1 file changed, 4 insertions(+), 3 deletions(-)
>>
>>diff --git a/drivers/peci/peci-dev.c b/drivers/peci/peci-dev.c
>>index e0fe09467a80..84e90af81ccc 100644
>>--- a/drivers/peci/peci-dev.c
>>+++ b/drivers/peci/peci-dev.c
>>@@ -122,8 +122,8 @@ static long peci_dev_ioctl(struct file *file, uint iocmd, ulong arg)
>> }
>> xmsg = peci_get_xfer_msg(uxmsg.tx_len, uxmsg.rx_len);
>>- if (IS_ERR(xmsg)) {
>>- ret = PTR_ERR(xmsg);
>>+ if (!xmsg) {
>>+ ret = -ENOMEM;
>
>Yes, it's a right fix. Thanks!
>
>> break;
>> }
>>@@ -162,7 +162,8 @@ static long peci_dev_ioctl(struct file *file, uint iocmd, ulong arg)
>> }
>> peci_put_xfer_msg(xmsg);
>>- kfree(msg);
>>+ if (!IS_ERR(msg))
>>+ kfree(msg);
>
>Not needed. kfree itself has null pointer checking inside.
>
Certainly, but the condition in question here isn't whether it's NULL,
but whether it's an ERR_PTR (which as far as I can tell kfree() does not
check for). As is, there's an error path that leads to passing a
non-NULL but also non-kfree-safe ERR_PTR (the memdup_user() return
value).
Zev
next prev parent reply other threads:[~2020-09-28 19:11 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-26 21:27 [PATCH 0/2] PECI patchset tweaks Zev Weiss
2020-09-26 21:27 ` [PATCH 1/2] peci: fix error-handling in peci_dev_ioctl() Zev Weiss
2020-09-28 19:03 ` Jae Hyun Yoo
2020-09-28 19:09 ` Zev Weiss [this message]
2020-09-28 19:37 ` Jae Hyun Yoo
2020-09-29 5:55 ` Joel Stanley
2020-09-26 21:27 ` [PATCH 2/2] peci-cputemp: label CPU cores from zero instead of one Zev Weiss
2020-09-28 19:08 ` Jae Hyun Yoo
2020-09-28 19:54 ` Zev Weiss
2020-09-28 20:21 ` Jae Hyun Yoo
2020-09-28 21:09 ` Zev Weiss
2020-09-28 21:32 ` Jae Hyun Yoo
2020-09-28 22:02 ` Zev Weiss
2020-09-28 22:20 ` Jae Hyun Yoo
2020-09-29 6:00 ` Joel Stanley
2020-10-06 18:01 ` Jae Hyun Yoo
2020-10-07 5:39 ` Joel Stanley
2020-09-28 19:01 ` [PATCH 0/2] PECI patchset tweaks Jae Hyun Yoo
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