From mboxrd@z Thu Jan  1 00:00:00 1970
From: Christoph Hellwig <hch@infradead.org>
Subject: Re: [PATCH 0/5] kallsyms: make kallsym APIs more safe with scnprintf
Date: Sat, 21 May 2022 23:07:52 -0700
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To: Maninder Singh <maninder1.s@samsung.com>
Cc: keescook@chromium.org, pmladek@suse.com, bcain@quicinc.com, mpe@ellerman.id.au, benh@kernel.crashing.org, paulus@samba.org, hca@linux.ibm.com, gor@linux.ibm.com, agordeev@linux.ibm.com, borntraeger@linux.ibm.com, svens@linux.ibm.com, satishkh@cisco.com, sebaddel@cisco.com, kartilak@cisco.com, jejb@linux.ibm.com, martin.petersen@oracle.com, mcgrof@kernel.org, jason.wessel@windriver.com, daniel.thompson@linaro.org, dianders@chromium.org, naveen.n.rao@linux.ibm.com, anil.s.keshavamurthy@intel.com, davem@davemloft.net, mhiramat@kernel.org, peterz@infradead.org, mingo@redhat.com, will@kernel.org, longman@redhat.com, boqun.feng@gmail.com, rostedt@goodmis.org, senozhatsky@chromium.org, andriy.shevchenko@linux.intel.com, linux@rasmusvillemoes.dk, akpm@linux-foundation.org, arnd@arndb.de

On Fri, May 20, 2022 at 02:06:56PM +0530, Maninder Singh wrote:
> kallsyms functionality depends on KSYM_NAME_LEN directly.
> but if user passed array length lesser than it, sprintf
> can cause issues of buffer overflow attack.
> 
> So changing *sprint* and *lookup* APIs in this patch set
> to have buffer size as an argument and replacing sprintf with
> scnprintf.

This is still a pretty horrible API.  Passing something like
a struct seq_buf seems like the much better API here.  Also with
the amount of arguments and by reference passing it might be worth
to pass them as a structure while you're at it.