Messages in this thread | | | From | William Roberts <> | Subject | RE: [RFC][PATCH 3/3] audit: Audit proc cmdline value | Date | Mon, 6 Jan 2014 17:26:15 +0000 |
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-----Original Message----- From: Mateusz Guzik [mailto:mguzik@redhat.com] Sent: Monday, January 06, 2014 9:09 AM To: William Roberts Cc: linux-audit@redhat.com; linux-mm@kvack.org; linux-kernel@vger.kernel.org; rgb@redhat.com; viro@zeniv.linux.org.uk; akpm@linux-foundation.org; sds@tycho.nsa.gov; William Roberts Subject: Re: [RFC][PATCH 3/3] audit: Audit proc cmdline value
I can't comment on the concept, but have one nit.
On Mon, Jan 06, 2014 at 07:30:30AM -0800, William Roberts wrote: > +static void audit_log_cmdline(struct audit_buffer *ab, struct task_struct *tsk, > + struct audit_context *context) > +{ > + int res; > + char *buf; > + char *msg = "(null)"; > + audit_log_format(ab, " cmdline="); > + > + /* Not cached */ > + if (!context->cmdline) { > + buf = kmalloc(PATH_MAX, GFP_KERNEL); > + if (!buf) > + goto out; > + res = get_cmdline(tsk, buf, PATH_MAX); > + /* Ensure NULL terminated */ > + if (buf[res-1] != '\0') > + buf[res-1] = '\0';
This accesses memory below the buffer if get_cmdline returned 0, which I believe will be the case when someone jokingly unmaps the area (all maybe when it is swapped out but can't be swapped in due to I/O errors). [William Roberts] Sorry for the weird inline posting (Thanks MS Outlook of doom). Anyways, this isn’t a nit. This is a major issue that should be dealt with. Thanks.
Also since you are just putting 0 in there anyway I don't see much point in testing for it.
> + context->cmdline = buf; > + } > + msg = context->cmdline; > +out: > + audit_log_untrustedstring(ab, msg); > +} > +
-- Mateusz Guzik
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