From: Benjamin Block <bblock@linux.ibm.com>
To: Romain Perier <romain.perier@gmail.com>
Cc: Kees Cook <keescook@chromium.org>,
kernel-hardening@lists.openwall.com,
Steffen Maier <maier@linux.ibm.com>,
linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 13/20] scsi: zfcp: Manual replacement of the deprecated strlcpy() with return values
Date: Mon, 22 Feb 2021 17:04:29 +0100 [thread overview]
Message-ID: <YDPWDU7iVTY7aY2h@t480-pf1aa2c2.linux.ibm.com> (raw)
In-Reply-To: <20210222151231.22572-14-romain.perier@gmail.com>
On Mon, Feb 22, 2021 at 04:12:24PM +0100, Romain Perier wrote:
> The strlcpy() reads the entire source buffer first, it is dangerous if
> the source buffer lenght is unbounded or possibility non NULL-terminated.
> It can lead to linear read overflows, crashes, etc...
>
> As recommended in the deprecated interfaces [1], it should be replaced
> by strscpy.
>
> This commit replaces all calls to strlcpy that handle the return values
> by the corresponding strscpy calls with new handling of the return
> values (as it is quite different between the two functions).
>
> [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
>
> Signed-off-by: Romain Perier <romain.perier@gmail.com>
> ---
> drivers/s390/scsi/zfcp_fc.c | 8 +++++---
> 1 file changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/s390/scsi/zfcp_fc.c b/drivers/s390/scsi/zfcp_fc.c
> index d24cafe02708..8a65241011b9 100644
> --- a/drivers/s390/scsi/zfcp_fc.c
> +++ b/drivers/s390/scsi/zfcp_fc.c
> @@ -877,14 +877,16 @@ static void zfcp_fc_rspn(struct zfcp_adapter *adapter,
> struct zfcp_fsf_ct_els *ct_els = &fc_req->ct_els;
> struct zfcp_fc_rspn_req *rspn_req = &fc_req->u.rspn.req;
> struct fc_ct_hdr *rspn_rsp = &fc_req->u.rspn.rsp;
> - int ret, len;
> + int ret;
> + ssize_t len;
>
> zfcp_fc_ct_ns_init(&rspn_req->ct_hdr, FC_NS_RSPN_ID,
> FC_SYMBOLIC_NAME_SIZE);
> hton24(rspn_req->rspn.fr_fid.fp_fid, fc_host_port_id(shost));
> - len = strlcpy(rspn_req->rspn.fr_name, fc_host_symbolic_name(shost),
> + len = strscpy(rspn_req->rspn.fr_name, fc_host_symbolic_name(shost),
> FC_SYMBOLIC_NAME_SIZE);
> - rspn_req->rspn.fr_name_len = len;
> + if (len != -E2BIG)
> + rspn_req->rspn.fr_name_len = len;
That is a bug. Leaving `rspn.fr_name_len` uninitialized defeats the
purpose of sending a RSPN.
How about:
if (len == -E2BIG)
rspn_req->rspn.fr_name_len = FC_SYMBOLIC_NAME_SIZE - 1;
else
rspn_req->rspn.fr_name_len = len;
>
> sg_init_one(&fc_req->sg_req, rspn_req, sizeof(*rspn_req));
> sg_init_one(&fc_req->sg_rsp, rspn_rsp, sizeof(*rspn_rsp));
>
--
Best Regards, Benjamin Block / Linux on IBM Z Kernel Development / IBM Systems
IBM Deutschland Research & Development GmbH / https://www.ibm.com/privacy
Vorsitz. AufsR.: Gregor Pillen / Geschäftsführung: Dirk Wittkopp
Sitz der Gesellschaft: Böblingen / Registergericht: AmtsG Stuttgart, HRB 243294
next prev parent reply other threads:[~2021-02-22 16:13 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-22 15:12 [PATCH 00/20] Manual replacement of all strlcpy in favor of strscpy Romain Perier
2021-02-22 15:12 ` [PATCH 01/20] cgroup: Manual replacement of the deprecated strlcpy() with return values Romain Perier
2021-02-23 16:13 ` Michal Koutný
2021-02-22 15:12 ` [PATCH 02/20] crypto: " Romain Perier
2021-03-04 4:37 ` Herbert Xu
2021-02-22 15:12 ` [PATCH 03/20] devlink: " Romain Perier
2021-02-23 0:56 ` Jakub Kicinski
2021-02-22 15:12 ` [PATCH 04/20] dma-buf: " Romain Perier
2021-02-22 15:12 ` [PATCH 05/20] kobject: " Romain Perier
2021-02-22 15:12 ` [PATCH 06/20] ima: " Romain Perier
2021-03-02 13:29 ` Mimi Zohar
2021-02-22 15:12 ` [PATCH 07/20] SUNRPC: " Romain Perier
2021-03-01 18:25 ` Chuck Lever
2021-02-22 15:12 ` [PATCH 08/20] kernfs: " Romain Perier
2021-02-22 15:12 ` [PATCH 09/20] m68k/atari: " Romain Perier
2021-02-22 15:12 ` [PATCH 10/20] module: " Romain Perier
2021-02-22 15:12 ` [PATCH 11/20] hwmon: " Romain Perier
2021-02-22 15:46 ` Guenter Roeck
2021-02-28 11:50 ` Joe Perches
2021-02-22 15:12 ` [PATCH 12/20] s390/hmcdrv: " Romain Perier
2021-02-22 15:12 ` [PATCH 13/20] scsi: zfcp: " Romain Perier
2021-02-22 16:04 ` Benjamin Block [this message]
2021-02-22 15:12 ` [PATCH 14/20] target: " Romain Perier
2021-02-22 16:00 ` Bodo Stroesser
2021-02-22 18:09 ` kernel test robot
2021-02-22 15:12 ` [PATCH 15/20] ALSA: usb-audio: " Romain Perier
2021-02-22 15:39 ` Takashi Iwai
2021-02-22 15:12 ` [PATCH 16/20] tracing/probe: " Romain Perier
2021-02-22 17:49 ` Steven Rostedt
2021-02-22 15:12 ` [PATCH 17/20] vt: " Romain Perier
2021-02-26 9:49 ` Jiri Slaby
2021-02-22 15:12 ` [PATCH 18/20] usb: gadget: f_midi: " Romain Perier
2021-02-22 15:12 ` [PATCH 19/20] usbip: usbip_host: " Romain Perier
2021-02-22 16:21 ` Shuah Khan
2021-02-28 9:03 ` Sergei Shtylyov
2021-02-22 15:12 ` [PATCH 20/20] s390/watchdog: " Romain Perier
2021-02-22 15:55 ` Guenter Roeck
2021-02-22 16:36 ` [PATCH 00/20] Manual replacement of all strlcpy in favor of strscpy Shuah Khan
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