From: Kees Cook <keescook@chromium.org>
To: M Chetan Kumar <m.chetan.kumar@intel.com>
Cc: Kees Cook <keescook@chromium.org>,
Florian Klink <flokli@flokli.de>,
Bagas Sanjaya <bagasdotme@gmail.com>,
Intel Corporation <linuxwwan@intel.com>,
Loic Poulain <loic.poulain@linaro.org>,
Sergey Ryazanov <ryazanov.s.a@gmail.com>,
Johannes Berg <johannes@sipsolutions.net>,
"David S. Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
"Gustavo A. R. Silva" <gustavoars@kernel.org>,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-hardening@vger.kernel.org
Subject: [PATCH] net: wwan: iosm: Convert single instance struct member to flexible array
Date: Tue, 20 Jun 2023 12:42:38 -0700 [thread overview]
Message-ID: <20230620194234.never.023-kees@kernel.org> (raw)
struct mux_adth actually ends with multiple struct mux_adth_dg members.
This is seen both in the comments about the member:
/**
* struct mux_adth - Structure of the Aggregated Datagram Table Header.
...
* @dg: datagramm table with variable length
*/
and in the preparation for populating it:
adth_dg_size = offsetof(struct mux_adth, dg) +
ul_adb->dg_count[i] * sizeof(*dg);
...
adth_dg_size -= offsetof(struct mux_adth, dg);
memcpy(&adth->dg, ul_adb->dg[i], adth_dg_size);
This was reported as a run-time false positive warning:
memcpy: detected field-spanning write (size 16) of single field "&adth->dg" at drivers/net/wwan/iosm/iosm_ipc_mux_codec.c:852 (size 8)
Adjust the struct mux_adth definition and associated sizeof() math; no binary
output differences are observed in the resulting object file.
Reported-by: Florian Klink <flokli@flokli.de>
Closes: https://lore.kernel.org/lkml/dbfa25f5-64c8-5574-4f5d-0151ba95d232@gmail.com/
Fixes: 1f52d7b62285 ("net: wwan: iosm: Enable M.2 7360 WWAN card support")
Cc: M Chetan Kumar <m.chetan.kumar@intel.com>
Cc: Bagas Sanjaya <bagasdotme@gmail.com>
Cc: Intel Corporation <linuxwwan@intel.com>
Cc: Loic Poulain <loic.poulain@linaro.org>
Cc: Sergey Ryazanov <ryazanov.s.a@gmail.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
drivers/net/wwan/iosm/iosm_ipc_mux_codec.c | 15 ++++++---------
drivers/net/wwan/iosm/iosm_ipc_mux_codec.h | 2 +-
2 files changed, 7 insertions(+), 10 deletions(-)
diff --git a/drivers/net/wwan/iosm/iosm_ipc_mux_codec.c b/drivers/net/wwan/iosm/iosm_ipc_mux_codec.c
index d6b166fc5c0e..bff46f7ca59f 100644
--- a/drivers/net/wwan/iosm/iosm_ipc_mux_codec.c
+++ b/drivers/net/wwan/iosm/iosm_ipc_mux_codec.c
@@ -626,14 +626,12 @@ static void mux_dl_adb_decode(struct iosm_mux *ipc_mux,
if (adth->signature != cpu_to_le32(IOSM_AGGR_MUX_SIG_ADTH))
goto adb_decode_err;
- if (le16_to_cpu(adth->table_length) < (sizeof(struct mux_adth) -
- sizeof(struct mux_adth_dg)))
+ if (le16_to_cpu(adth->table_length) < sizeof(struct mux_adth))
goto adb_decode_err;
/* Calculate the number of datagrams. */
nr_of_dg = (le16_to_cpu(adth->table_length) -
- sizeof(struct mux_adth) +
- sizeof(struct mux_adth_dg)) /
+ sizeof(struct mux_adth)) /
sizeof(struct mux_adth_dg);
/* Is the datagram table empty ? */
@@ -649,7 +647,7 @@ static void mux_dl_adb_decode(struct iosm_mux *ipc_mux,
}
/* New aggregated datagram table. */
- dg = &adth->dg;
+ dg = adth->dg;
if (mux_dl_process_dg(ipc_mux, adbh, dg, skb, if_id,
nr_of_dg) < 0)
goto adb_decode_err;
@@ -849,7 +847,7 @@ static void ipc_mux_ul_encode_adth(struct iosm_mux *ipc_mux,
adth->if_id = i;
adth->table_length = cpu_to_le16(adth_dg_size);
adth_dg_size -= offsetof(struct mux_adth, dg);
- memcpy(&adth->dg, ul_adb->dg[i], adth_dg_size);
+ memcpy(adth->dg, ul_adb->dg[i], adth_dg_size);
ul_adb->if_cnt++;
}
@@ -1426,14 +1424,13 @@ static int ipc_mux_get_payload_from_adb(struct iosm_mux *ipc_mux,
if (adth->signature == cpu_to_le32(IOSM_AGGR_MUX_SIG_ADTH)) {
nr_of_dg = (le16_to_cpu(adth->table_length) -
- sizeof(struct mux_adth) +
- sizeof(struct mux_adth_dg)) /
+ sizeof(struct mux_adth)) /
sizeof(struct mux_adth_dg);
if (nr_of_dg <= 0)
return payload_size;
- dg = &adth->dg;
+ dg = adth->dg;
for (i = 0; i < nr_of_dg; i++, dg++) {
if (le32_to_cpu(dg->datagram_index) <
diff --git a/drivers/net/wwan/iosm/iosm_ipc_mux_codec.h b/drivers/net/wwan/iosm/iosm_ipc_mux_codec.h
index 5d4e3b89542c..f8df88f816c4 100644
--- a/drivers/net/wwan/iosm/iosm_ipc_mux_codec.h
+++ b/drivers/net/wwan/iosm/iosm_ipc_mux_codec.h
@@ -161,7 +161,7 @@ struct mux_adth {
u8 opt_ipv4v6;
__le32 next_table_index;
__le32 reserved2;
- struct mux_adth_dg dg;
+ struct mux_adth_dg dg[];
};
/**
--
2.34.1
next reply other threads:[~2023-06-20 19:42 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-20 19:42 Kees Cook [this message]
2023-06-20 21:17 ` [PATCH] net: wwan: iosm: Convert single instance struct member to flexible array Gustavo A. R. Silva
2023-06-21 14:49 ` Simon Horman
2023-06-22 9:40 ` patchwork-bot+netdevbpf
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