| 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
| ||
|
Message-ID: <CAEAWyHfcviAwhjFPY11na8cKSAeD830DRcgetFvPJ2OCJE1MnQ@mail.gmail.com>
Date: Wed, 16 Apr 2025 20:15:36 -0700
From: Harshitha Ramamurthy <hramamurthy@...gle.com>
To: Kees Cook <kees@...nel.org>
Cc: Jakub Kicinski <kuba@...nel.org>, Andrew Lunn <andrew+netdev@...n.ch>,
"David S. Miller" <davem@...emloft.net>, Eric Dumazet <edumazet@...gle.com>,
Paolo Abeni <pabeni@...hat.com>, Claudiu Manoil <claudiu.manoil@....com>,
Vladimir Oltean <vladimir.oltean@....com>, Wei Fang <wei.fang@....com>,
Clark Wang <xiaoning.wang@....com>, Jeroen de Borst <jeroendb@...gle.com>,
Ido Schimmel <idosch@...dia.com>, Petr Machata <petrm@...dia.com>,
Maxime Coquelin <mcoquelin.stm32@...il.com>, Alexandre Torgue <alexandre.torgue@...s.st.com>,
Simon Horman <horms@...nel.org>, Geoff Levand <geoff@...radead.org>,
Wolfram Sang <wsa+renesas@...g-engineering.com>,
Alexander Lobakin <aleksander.lobakin@...el.com>,
Praveen Kaligineedi <pkaligineedi@...gle.com>, Willem de Bruijn <willemb@...gle.com>,
Joshua Washington <joshwash@...gle.com>, Furong Xu <0x1207@...il.com>,
"Russell King (Oracle)" <rmk+kernel@...linux.org.uk>, Jisheng Zhang <jszhang@...nel.org>,
Petr Tesarik <petr@...arici.cz>, netdev@...r.kernel.org, imx@...ts.linux.dev,
linux-stm32@...md-mailman.stormreply.com,
linux-arm-kernel@...ts.infradead.org,
Richard Cochran <richardcochran@...il.com>, Jacob Keller <jacob.e.keller@...el.com>,
Shannon Nelson <shannon.nelson@....com>, Ziwei Xiao <ziweixiao@...gle.com>,
Shailend Chand <shailend@...gle.com>, Choong Yong Liang <yong.liang.choong@...ux.intel.com>,
Andrew Halaney <ahalaney@...hat.com>, Kory Maincent <kory.maincent@...tlin.com>,
linux-kernel@...r.kernel.org, linux-hardening@...r.kernel.org
Subject: Re: [PATCH] net: ethtool: Adjust exactly ETH_GSTRING_LEN-long stats
to use memcpy
On Tue, Apr 15, 2025 at 6:02 PM Kees Cook <kees@...nel.org> wrote:
>
> Many drivers populate the stats buffer using C-String based APIs (e.g.
> ethtool_sprintf() and ethtool_puts()), usually when building up the
> list of stats individually (i.e. with a for() loop). This, however,
> requires that the source strings be populated in such a way as to have
> a terminating NUL byte in the source.
>
> Other drivers populate the stats buffer directly using one big memcpy()
> of an entire array of strings. No NUL termination is needed here, as the
> bytes are being directly passed through. Yet others will build up the
> stats buffer individually, but also use memcpy(). This, too, does not
> need NUL termination of the source strings.
>
> However, there are cases where the strings that populate the
> source stats strings are exactly ETH_GSTRING_LEN long, and GCC
> 15's -Wunterminated-string-initialization option complains that the
> trailing NUL byte has been truncated. This situation is fine only if the
> driver is using the memcpy() approach. If the C-String APIs are used,
> the destination string name will have its final byte truncated by the
> required trailing NUL byte applied by the C-string API.
>
> For drivers that are already using memcpy() but have initializers that
> truncate the NUL terminator, mark their source strings as __nonstring to
> silence the GCC warnings.
>
> For drivers that have initializers that truncate the NUL terminator and
> are using the C-String APIs, switch to memcpy() to avoid destination
> string truncation and mark their source strings as __nonstring to silence
> the GCC warnings. (Also introduce ethtool_cpy() as a helper to make this
> an easy replacement).
>
> Specifically the following warnings were investigated and addressed:
>
> ../drivers/net/ethernet/chelsio/cxgb/cxgb2.c:364:9: warning: initializer-string for array of 'char' truncates NUL terminator but destination lacks 'nonstring' attribute (33 chars into 32 available) [-Wunterminated-string-initialization]
> 364 | "TxFramesAbortedDueToXSCollisions",
> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> ../drivers/net/ethernet/freescale/enetc/enetc_ethtool.c:165:33: warning: initializer-string for array of 'char' truncates NUL terminator but destination lacks 'nonstring' attribute (33 chars into 32 available) [-Wunterminated-string-initialization]
> 165 | { ENETC_PM_R1523X(0), "MAC rx 1523 to max-octet packets" },
> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> ../drivers/net/ethernet/freescale/enetc/enetc_ethtool.c:190:33: warning: initializer-string for array of 'char' truncates NUL terminator but destination lacks 'nonstring' attribute (33 chars into 32 available) [-Wunterminated-string-initialization]
> 190 | { ENETC_PM_T1523X(0), "MAC tx 1523 to max-octet packets" },
> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> ../drivers/net/ethernet/google/gve/gve_ethtool.c:76:9: warning: initializer-string for array of 'char' truncates NUL terminator but destination lacks 'nonstring' attribute (33 chars into 32 available) [-Wunterminated-string-initialization]
> 76 | "adminq_dcfg_device_resources_cnt", "adminq_set_driver_parameter_cnt",
> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> ../drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c:117:53: warning: initializer-string for array of 'char' truncates NUL terminator but destination lacks 'nonstring' attribute (33 chars into 32 available) [-Wunterminated-string-initialization]
> 117 | STMMAC_STAT(ptp_rx_msg_type_pdelay_follow_up),
> | ^
> ../drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c:46:12: note: in definition of macro 'STMMAC_STAT'
> 46 | { #m, sizeof_field(struct stmmac_extra_stats, m), \
> | ^
> ../drivers/net/ethernet/mellanox/mlxsw/spectrum_ethtool.c:328:24: warning: initializer-string for array of 'char' truncates NUL terminator but destination lacks 'nonstring' attribute (33 chars into 32 available) [-Wunterminated-string-initialization]
> 328 | .str = "a_mac_control_frames_transmitted",
> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> ../drivers/net/ethernet/mellanox/mlxsw/spectrum_ethtool.c:340:24: warning: initializer-string for array of 'char' truncates NUL terminator but destination lacks 'nonstring' attribute (33 chars into 32 available) [-Wunterminated-string-initialization]
> 340 | .str = "a_pause_mac_ctrl_frames_received",
> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> Signed-off-by: Kees Cook <kees@...nel.org>
Thanks for the patch! For the gve part:
Reviewed-by: Harshitha Ramamurthy <hramamurthy@...gle.com>
> ---
> Cc: Jakub Kicinski <kuba@...nel.org>
> Cc: Andrew Lunn <andrew+netdev@...n.ch>
> Cc: "David S. Miller" <davem@...emloft.net>
> Cc: Eric Dumazet <edumazet@...gle.com>
> Cc: Paolo Abeni <pabeni@...hat.com>
> Cc: Claudiu Manoil <claudiu.manoil@....com>
> Cc: Vladimir Oltean <vladimir.oltean@....com>
> Cc: Wei Fang <wei.fang@....com>
> Cc: Clark Wang <xiaoning.wang@....com>
> Cc: Jeroen de Borst <jeroendb@...gle.com>
> Cc: Harshitha Ramamurthy <hramamurthy@...gle.com>
> Cc: Ido Schimmel <idosch@...dia.com>
> Cc: Petr Machata <petrm@...dia.com>
> Cc: Maxime Coquelin <mcoquelin.stm32@...il.com>
> Cc: Alexandre Torgue <alexandre.torgue@...s.st.com>
> Cc: Simon Horman <horms@...nel.org>
> Cc: Geoff Levand <geoff@...radead.org>
> Cc: Wolfram Sang <wsa+renesas@...g-engineering.com>
> Cc: Alexander Lobakin <aleksander.lobakin@...el.com>
> Cc: Praveen Kaligineedi <pkaligineedi@...gle.com>
> Cc: Willem de Bruijn <willemb@...gle.com>
> Cc: Joshua Washington <joshwash@...gle.com>
> Cc: Furong Xu <0x1207@...il.com>
> Cc: "Russell King (Oracle)" <rmk+kernel@...linux.org.uk>
> Cc: Jisheng Zhang <jszhang@...nel.org>
> Cc: Petr Tesarik <petr@...arici.cz>
> Cc: netdev@...r.kernel.org
> Cc: imx@...ts.linux.dev
> Cc: linux-stm32@...md-mailman.stormreply.com
> Cc: linux-arm-kernel@...ts.infradead.org
> ---
> drivers/net/ethernet/chelsio/cxgb/cxgb2.c | 2 +-
> drivers/net/ethernet/freescale/enetc/enetc_ethtool.c | 4 ++--
> drivers/net/ethernet/google/gve/gve_ethtool.c | 4 ++--
> .../net/ethernet/mellanox/mlxsw/spectrum_ethtool.c | 2 +-
> drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c | 2 +-
> include/linux/ethtool.h | 11 +++++++++++
> 6 files changed, 18 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/net/ethernet/chelsio/cxgb/cxgb2.c b/drivers/net/ethernet/chelsio/cxgb/cxgb2.c
> index 3b7068832f95..4a0e2d2eb60a 100644
> --- a/drivers/net/ethernet/chelsio/cxgb/cxgb2.c
> +++ b/drivers/net/ethernet/chelsio/cxgb/cxgb2.c
> @@ -351,7 +351,7 @@ static void set_msglevel(struct net_device *dev, u32 val)
> adapter->msg_enable = val;
> }
>
> -static const char stats_strings[][ETH_GSTRING_LEN] = {
> +static const char stats_strings[][ETH_GSTRING_LEN] __nonstring_array = {
> "TxOctetsOK",
> "TxOctetsBad",
> "TxUnicastFramesOK",
> diff --git a/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c b/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c
> index ece3ae28ba82..f47c8b6cc511 100644
> --- a/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c
> +++ b/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c
> @@ -141,7 +141,7 @@ static const struct {
>
> static const struct {
> int reg;
> - char name[ETH_GSTRING_LEN];
> + char name[ETH_GSTRING_LEN] __nonstring;
> } enetc_port_counters[] = {
> { ENETC_PM_REOCT(0), "MAC rx ethernet octets" },
> { ENETC_PM_RALN(0), "MAC rx alignment errors" },
> @@ -264,7 +264,7 @@ static void enetc_get_strings(struct net_device *ndev, u32 stringset, u8 *data)
> break;
>
> for (i = 0; i < ARRAY_SIZE(enetc_port_counters); i++)
> - ethtool_puts(&data, enetc_port_counters[i].name);
> + ethtool_cpy(&data, enetc_port_counters[i].name);
>
> break;
> }
> diff --git a/drivers/net/ethernet/google/gve/gve_ethtool.c b/drivers/net/ethernet/google/gve/gve_ethtool.c
> index eae1a7595a69..3c1da0cf3f61 100644
> --- a/drivers/net/ethernet/google/gve/gve_ethtool.c
> +++ b/drivers/net/ethernet/google/gve/gve_ethtool.c
> @@ -67,7 +67,7 @@ static const char gve_gstrings_tx_stats[][ETH_GSTRING_LEN] = {
> "tx_xsk_sent[%u]", "tx_xdp_xmit[%u]", "tx_xdp_xmit_errors[%u]"
> };
>
> -static const char gve_gstrings_adminq_stats[][ETH_GSTRING_LEN] = {
> +static const char gve_gstrings_adminq_stats[][ETH_GSTRING_LEN] __nonstring_array = {
> "adminq_prod_cnt", "adminq_cmd_fail", "adminq_timeouts",
> "adminq_describe_device_cnt", "adminq_cfg_device_resources_cnt",
> "adminq_register_page_list_cnt", "adminq_unregister_page_list_cnt",
> @@ -113,7 +113,7 @@ static void gve_get_strings(struct net_device *netdev, u32 stringset, u8 *data)
> i);
>
> for (i = 0; i < ARRAY_SIZE(gve_gstrings_adminq_stats); i++)
> - ethtool_puts(&s, gve_gstrings_adminq_stats[i]);
> + ethtool_cpy(&s, gve_gstrings_adminq_stats[i]);
>
> break;
>
> diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_ethtool.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_ethtool.c
> index 3f64cdbabfa3..0a8fb9c842d3 100644
> --- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_ethtool.c
> +++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_ethtool.c
> @@ -262,7 +262,7 @@ static int mlxsw_sp_port_set_pauseparam(struct net_device *dev,
> }
>
> struct mlxsw_sp_port_hw_stats {
> - char str[ETH_GSTRING_LEN];
> + char str[ETH_GSTRING_LEN] __nonstring;
> u64 (*getter)(const char *payload);
> bool cells_bytes;
> };
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c
> index 918a32f8fda8..844f7d516a40 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c
> @@ -37,7 +37,7 @@
> #define ETHTOOL_DMA_OFFSET 55
>
> struct stmmac_stats {
> - char stat_string[ETH_GSTRING_LEN];
> + char stat_string[ETH_GSTRING_LEN] __nonstring;
> int sizeof_stat;
> int stat_offset;
> };
> diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h
> index 013d25858642..7edb5f5e7134 100644
> --- a/include/linux/ethtool.h
> +++ b/include/linux/ethtool.h
> @@ -1330,6 +1330,17 @@ extern __printf(2, 3) void ethtool_sprintf(u8 **data, const char *fmt, ...);
> */
> extern void ethtool_puts(u8 **data, const char *str);
>
> +/**
> + * ethtool_cpy - Write possibly-not-NUL-terminated string to ethtool string data
> + * @data: Pointer to a pointer to the start of string to write into
> + * @str: NUL-byte padded char array of size ETH_GSTRING_LEN to copy from
> + */
> +#define ethtool_cpy(data, str) do { \
> + BUILD_BUG_ON(sizeof(str) != ETH_GSTRING_LEN); \
> + memcpy(*(data), str, ETH_GSTRING_LEN); \
> + *(data) += ETH_GSTRING_LEN; \
> +} while (0)
> +
> /* Link mode to forced speed capabilities maps */
> struct ethtool_forced_speed_map {
> u32 speed;
> --
> 2.34.1
>
Powered by blists - more mailing lists