From mboxrd@z Thu Jan 1 00:00:00 1970 From: Richard Guy Briggs Subject: Re: [PATCH v5 1/3] mm: Create utility function for accessing a tasks commandline value Date: Tue, 11 Feb 2014 11:29:44 -0500 Message-ID: <20140211162944.GK18807@madcap2.tricolour.ca> References: <1391710528-23481-1-git-send-email-wroberts@tresys.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <1391710528-23481-1-git-send-email-wroberts@tresys.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-audit-bounces@redhat.com Errors-To: linux-audit-bounces@redhat.com To: William Roberts Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, William Roberts , linux-audit@redhat.com, viro@zeniv.linux.org.uk, akpm@linux-foundation.org List-Id: linux-mm.kvack.org On 14/02/06, William Roberts wrote: > introduce get_cmdline() for retreiving the value of a processes > proc/self/cmdline value. > > Acked-by: David Rientjes > Acked-by: Stephen Smalley Acked-by: Richard Guy Briggs > Signed-off-by: William Roberts > --- > include/linux/mm.h | 1 + > mm/util.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 49 insertions(+) > > diff --git a/include/linux/mm.h b/include/linux/mm.h > index f28f46e..db89a94 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -1175,6 +1175,7 @@ void account_page_writeback(struct page *page); > int set_page_dirty(struct page *page); > int set_page_dirty_lock(struct page *page); > int clear_page_dirty_for_io(struct page *page); > +int get_cmdline(struct task_struct *task, char *buffer, int buflen); > > /* Is the vma a continuation of the stack vma above it? */ > static inline int vma_growsdown(struct vm_area_struct *vma, unsigned long addr) > diff --git a/mm/util.c b/mm/util.c > index a24aa22..8122710 100644 > --- a/mm/util.c > +++ b/mm/util.c > @@ -445,6 +445,54 @@ unsigned long vm_commit_limit(void) > return allowed; > } > > +/** > + * get_cmdline() - copy the cmdline value to a buffer. > + * @task: the task whose cmdline value to copy. > + * @buffer: the buffer to copy to. > + * @buflen: the length of the buffer. Larger cmdline values are truncated > + * to this length. > + * Returns the size of the cmdline field copied. Note that the copy does > + * not guarantee an ending NULL byte. > + */ > +int get_cmdline(struct task_struct *task, char *buffer, int buflen) > +{ > + int res = 0; > + unsigned int len; > + struct mm_struct *mm = get_task_mm(task); > + if (!mm) > + goto out; > + if (!mm->arg_end) > + goto out_mm; /* Shh! No looking before we're done */ > + > + len = mm->arg_end - mm->arg_start; > + > + if (len > buflen) > + len = buflen; > + > + res = access_process_vm(task, mm->arg_start, buffer, len, 0); > + > + /* > + * If the nul at the end of args has been overwritten, then > + * assume application is using setproctitle(3). > + */ > + if (res > 0 && buffer[res-1] != '\0' && len < buflen) { > + len = strnlen(buffer, res); > + if (len < res) { > + res = len; > + } else { > + len = mm->env_end - mm->env_start; > + if (len > buflen - res) > + len = buflen - res; > + res += access_process_vm(task, mm->env_start, > + buffer+res, len, 0); > + res = strnlen(buffer, res); > + } > + } > +out_mm: > + mmput(mm); > +out: > + return res; > +} > > /* Tracepoints definitions. */ > EXPORT_TRACEPOINT_SYMBOL(kmalloc); > -- > 1.7.9.5 > - RGB -- Richard Guy Briggs Senior Software Engineer, Kernel Security, AMER ENG Base Operating Systems, Red Hat Remote, Ottawa, Canada Voice: +1.647.777.2635, Internal: (81) 32635, Alt: +1.613.693.0684x3545