Messages in this thread | | | Subject | Re: [PATCH v3] proc_sysctl: fix oops caused by incorrect command parameters. | From | Xiaoming Ni <> | Date | Tue, 12 Jan 2021 14:24:05 +0800 |
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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
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