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 <[email protected]>
Closes: https://lore.kernel.org/lkml/[email protected]/
Fixes: 1f52d7b62285 ("net: wwan: iosm: Enable M.2 7360 WWAN card support")
Cc: M Chetan Kumar <[email protected]>
Cc: Bagas Sanjaya <[email protected]>
Cc: Intel Corporation <[email protected]>
Cc: Loic Poulain <[email protected]>
Cc: Sergey Ryazanov <[email protected]>
Cc: Johannes Berg <[email protected]>
Cc: "David S. Miller" <[email protected]>
Cc: Eric Dumazet <[email protected]>
Cc: Jakub Kicinski <[email protected]>
Cc: Paolo Abeni <[email protected]>
Cc: "Gustavo A. R. Silva" <[email protected]>
Cc: [email protected]
Signed-off-by: Kees Cook <[email protected]>
---
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
On Tue, Jun 20, 2023 at 12:42:38PM -0700, Kees Cook wrote:
> 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 <[email protected]>
> Closes: https://lore.kernel.org/lkml/[email protected]/
> Fixes: 1f52d7b62285 ("net: wwan: iosm: Enable M.2 7360 WWAN card support")
> Cc: M Chetan Kumar <[email protected]>
> Cc: Bagas Sanjaya <[email protected]>
> Cc: Intel Corporation <[email protected]>
> Cc: Loic Poulain <[email protected]>
> Cc: Sergey Ryazanov <[email protected]>
> Cc: Johannes Berg <[email protected]>
> Cc: "David S. Miller" <[email protected]>
> Cc: Eric Dumazet <[email protected]>
> Cc: Jakub Kicinski <[email protected]>
> Cc: Paolo Abeni <[email protected]>
> Cc: "Gustavo A. R. Silva" <[email protected]>
> Cc: [email protected]
> Signed-off-by: Kees Cook <[email protected]>
Reviewed-by: Gustavo A. R. Silva <[email protected]>
Thank god they used offsetof(struct mux_adth, dg) everywhere. :P
--
Gustavo
> ---
> 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
>
On Tue, Jun 20, 2023 at 12:42:38PM -0700, Kees Cook wrote:
> 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 <[email protected]>
> Closes: https://lore.kernel.org/lkml/[email protected]/
> Fixes: 1f52d7b62285 ("net: wwan: iosm: Enable M.2 7360 WWAN card support")
> Cc: M Chetan Kumar <[email protected]>
> Cc: Bagas Sanjaya <[email protected]>
> Cc: Intel Corporation <[email protected]>
> Cc: Loic Poulain <[email protected]>
> Cc: Sergey Ryazanov <[email protected]>
> Cc: Johannes Berg <[email protected]>
> Cc: "David S. Miller" <[email protected]>
> Cc: Eric Dumazet <[email protected]>
> Cc: Jakub Kicinski <[email protected]>
> Cc: Paolo Abeni <[email protected]>
> Cc: "Gustavo A. R. Silva" <[email protected]>
> Cc: [email protected]
> Signed-off-by: Kees Cook <[email protected]>
> ---
> 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(-)
Reviewed-by: Simon Horman <[email protected]>
Hello:
This patch was applied to netdev/net.git (main)
by Paolo Abeni <[email protected]>:
On Tue, 20 Jun 2023 12:42:38 -0700 you wrote:
> 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
> */
>
> [...]
Here is the summary with links:
- net: wwan: iosm: Convert single instance struct member to flexible array
https://git.kernel.org/netdev/net/c/dec24b3b3394
You are awesome, thank you!
--
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