From: Xiaoming Ni <nixiaoming@huawei.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: <linux-kernel@vger.kernel.org>, <mcgrof@kernel.org>,
<keescook@chromium.org>, <yzaikin@google.com>,
<adobriyan@gmail.com>, <linux-fsdevel@vger.kernel.org>,
<vbabka@suse.cz>, <mhocko@suse.com>, <andy.shevchenko@gmail.com>,
<wangle6@huawei.com>
Subject: Re: [PATCH v3] proc_sysctl: fix oops caused by incorrect command parameters.
Date: Tue, 12 Jan 2021 14:24:05 +0800 [thread overview]
Message-ID: <89d1369e-f0a8-66f2-c0ea-3aac3a55e2c1@huawei.com> (raw)
In-Reply-To: <20210111203340.98dd3c8fa675b709bcf6d49e@linux-foundation.org>
On 2021/1/12 12:33, Andrew Morton wrote:
> On Tue, 12 Jan 2021 11:31:55 +0800 Xiaoming Ni <nixiaoming@huawei.com> wrote:
>
>> The process_sysctl_arg() does not check whether val is empty before
>> invoking strlen(val). If the command line parameter () is incorrectly
>> configured and val is empty, oops is triggered.
>>
>> --- a/fs/proc/proc_sysctl.c
>> +++ b/fs/proc/proc_sysctl.c
>> @@ -1770,6 +1770,9 @@ static int process_sysctl_arg(char *param, char *val,
>> return 0;
>> }
>>
>> + if (!val)
>> + return -EINVAL;
>> +
>
> I think v2 (return 0) was preferable. Because all the other error-out
> cases in process_sysctl_arg() also do a `return 0'.
https://lore.kernel.org/lkml/bc098af4-c0cd-212e-d09d-46d617d0acab@huawei.com/
patch4:
+++ b/fs/proc/proc_sysctl.c
@@ -1757,6 +1757,9 @@ static int process_sysctl_arg(char *param,
char *val,
loff_t pos = 0;
ssize_t wret;
+ if (!val)
+ return 0;
+
if (strncmp(param, "sysctl", sizeof("sysctl") - 1) == 0) {
param += sizeof("sysctl") - 1;
Is this the version you're talking about?
>
> If we're going to do a separate "patch: make process_sysctl_arg()
> return an errno instead of 0" then fine, we can discuss that. But it's
> conceptually a different work from fixing this situation.
> .
>
However, are the logs generated by process_sysctl_arg() clearer and more
accurate than parse_args()? Should the logs generated by
process_sysctl_arg() be deleted?
Thanks
Xiaoming Ni
next prev parent reply other threads:[~2021-01-12 6:25 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-12 3:31 [PATCH v3] proc_sysctl: fix oops caused by incorrect command parameters Xiaoming Ni
2021-01-12 4:33 ` Andrew Morton
2021-01-12 6:24 ` Xiaoming Ni [this message]
2021-01-12 6:28 ` Andrew Morton
2021-01-12 7:24 ` Michal Hocko
2021-01-12 11:42 ` Vlastimil Babka
2021-01-17 2:59 ` Xiaoming Ni
2021-01-18 10:50 ` Vlastimil Babka
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