linux-kernel - RE: [PATCH v2 1/5] kprobes: convert kprobe_lookup

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <063D6719AE5E284EB5DD2968C1650D6DCFFD3C07@AcuExch.aculab.com>
Date:   Tue, 18 Apr 2017 12:52:10 +0000
From:   David Laight <David.Laight@...LAB.COM>
To:     "'Naveen N. Rao'" <naveen.n.rao@...ux.vnet.ibm.com>,
        Michael Ellerman <mpe@...erman.id.au>
CC:     "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "linuxppc-dev@...ts.ozlabs.org" <linuxppc-dev@...ts.ozlabs.org>,
        "Masami Hiramatsu" <mhiramat@...nel.org>,
        Ingo Molnar <mingo@...nel.org>
Subject: RE: [PATCH v2 1/5] kprobes: convert kprobe_lookup_name() to a
 function

From: Naveen N. Rao
> Sent: 12 April 2017 11:58
...
> +kprobe_opcode_t *kprobe_lookup_name(const char *name)
> +{
...
> +	char dot_name[MODULE_NAME_LEN + 1 + KSYM_NAME_LEN];
> +	const char *modsym;
> +	bool dot_appended = false;
> +	if ((modsym = strchr(name, ':')) != NULL) {
> +		modsym++;
> +		if (*modsym != '\0' && *modsym != '.') {
> +			/* Convert to <module:.symbol> */
> +			strncpy(dot_name, name, modsym - name);
> +			dot_name[modsym - name] = '.';
> +			dot_name[modsym - name + 1] = '\0';
> +			strncat(dot_name, modsym,
> +				sizeof(dot_name) - (modsym - name) - 2);
> +			dot_appended = true;

If the ':' is 'a way down' name[] then although the strncpy() won't
overrun dot_name[] the rest of the code can.

The strncat() call is particularly borked.

	David