diff mbox series

[v2,2/5] treewide: Replace open-coded flex arrays in unions

Message ID 20210826050458.1540622-3-keescook@chromium.org (mailing list archive)
State Not Applicable
Headers show
Series None | expand

Commit Message

Kees Cook Aug. 26, 2021, 5:04 a.m. UTC
In support of enabling -Warray-bounds and -Wzero-length-bounds and
correctly handling run-time memcpy() bounds checking, replace all
open-coded flexible arrays (i.e. 0-element arrays) in unions with the
flex_array() helper macro.

This fixes warnings such as:

fs/hpfs/anode.c: In function 'hpfs_add_sector_to_btree':
fs/hpfs/anode.c:209:27: warning: array subscript 0 is outside the bounds of an interior zero-length array 'struct bplus_internal_node[0]' [-Wzero-length-bounds]
  209 |    anode->btree.u.internal[0].down = cpu_to_le32(a);
      |    ~~~~~~~~~~~~~~~~~~~~~~~^~~
In file included from fs/hpfs/hpfs_fn.h:26,
                 from fs/hpfs/anode.c:10:
fs/hpfs/hpfs.h:412:32: note: while referencing 'internal'
  412 |     struct bplus_internal_node internal[0]; /* (internal) 2-word entries giving
      |                                ^~~~~~~~

drivers/net/can/usb/etas_es58x/es58x_fd.c: In function 'es58x_fd_tx_can_msg':
drivers/net/can/usb/etas_es58x/es58x_fd.c:360:35: warning: array subscript 65535 is outside the bounds of an interior zero-length array 'u8[0]' {aka 'unsigned char[]'} [-Wzero-length-bounds]
  360 |  tx_can_msg = (typeof(tx_can_msg))&es58x_fd_urb_cmd->raw_msg[msg_len];
      |                                   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from drivers/net/can/usb/etas_es58x/es58x_core.h:22,
                 from drivers/net/can/usb/etas_es58x/es58x_fd.c:17:
drivers/net/can/usb/etas_es58x/es58x_fd.h:231:6: note: while referencing 'raw_msg'
  231 |   u8 raw_msg[0];
      |      ^~~~~~~

Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Ayush Sawal <ayush.sawal@chelsio.com>
Cc: Vinay Kumar Yadav <vinay.yadav@chelsio.com>
Cc: Rohit Maheshwari <rohitm@chelsio.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Stanislaw Gruszka <stf_xl@wp.pl>
Cc: Luca Coelho <luciano.coelho@intel.com>
Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Yonghong Song <yhs@fb.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: KP Singh <kpsingh@kernel.org>
Cc: Johannes Berg <johannes.berg@intel.com>
Cc: Mordechay Goodstein <mordechay.goodstein@intel.com>
Cc: Lee Jones <lee.jones@linaro.org>
Cc: Wolfgang Grandegger <wg@grandegger.com>
Cc: Marc Kleine-Budde <mkl@pengutronix.de>
Cc: Arunachalam Santhanam <arunachalam.santhanam@in.bosch.com>
Cc: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Cc: Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>
Cc: linux-crypto@vger.kernel.org
Cc: ath10k@lists.infradead.org
Cc: linux-wireless@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: linux-scsi@vger.kernel.org
Cc: linux-can@vger.kernel.org
Cc: bpf@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 drivers/crypto/chelsio/chcr_crypto.h              | 14 +++++++++-----
 drivers/net/can/usb/etas_es58x/es581_4.h          |  2 +-
 drivers/net/can/usb/etas_es58x/es58x_fd.h         |  2 +-
 drivers/net/wireless/ath/ath10k/htt.h             |  7 +++++--
 drivers/net/wireless/intel/iwlegacy/commands.h    |  6 ++++--
 drivers/net/wireless/intel/iwlwifi/dvm/commands.h |  6 ++++--
 drivers/net/wireless/intel/iwlwifi/fw/api/tx.h    |  6 ++++--
 drivers/scsi/aic94xx/aic94xx_sds.c                |  6 ++++--
 fs/hpfs/hpfs.h                                    |  8 ++++----
 include/linux/filter.h                            |  6 ++++--
 include/scsi/sas.h                                | 12 ++++++++----
 include/uapi/rdma/rdma_user_rxe.h                 |  4 ++--
 include/uapi/sound/asoc.h                         |  4 ++--
 13 files changed, 52 insertions(+), 31 deletions(-)

Comments

Marc Kleine-Budde Aug. 26, 2021, 6:24 a.m. UTC | #1
On 25.08.2021 22:04:55, Kees Cook wrote:
> In support of enabling -Warray-bounds and -Wzero-length-bounds and
> correctly handling run-time memcpy() bounds checking, replace all
> open-coded flexible arrays (i.e. 0-element arrays) in unions with the
> flex_array() helper macro.
> 
> This fixes warnings such as:
> 
> fs/hpfs/anode.c: In function 'hpfs_add_sector_to_btree':
> fs/hpfs/anode.c:209:27: warning: array subscript 0 is outside the bounds of an interior zero-length array 'struct bplus_internal_node[0]' [-Wzero-length-bounds]
>   209 |    anode->btree.u.internal[0].down = cpu_to_le32(a);
>       |    ~~~~~~~~~~~~~~~~~~~~~~~^~~
> In file included from fs/hpfs/hpfs_fn.h:26,
>                  from fs/hpfs/anode.c:10:
> fs/hpfs/hpfs.h:412:32: note: while referencing 'internal'
>   412 |     struct bplus_internal_node internal[0]; /* (internal) 2-word entries giving
>       |                                ^~~~~~~~
> 
> drivers/net/can/usb/etas_es58x/es58x_fd.c: In function 'es58x_fd_tx_can_msg':
> drivers/net/can/usb/etas_es58x/es58x_fd.c:360:35: warning: array subscript 65535 is outside the bounds of an interior zero-length array 'u8[0]' {aka 'unsigned char[]'} [-Wzero-length-bounds]
>   360 |  tx_can_msg = (typeof(tx_can_msg))&es58x_fd_urb_cmd->raw_msg[msg_len];
>       |                                   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> In file included from drivers/net/can/usb/etas_es58x/es58x_core.h:22,
>                  from drivers/net/can/usb/etas_es58x/es58x_fd.c:17:
> drivers/net/can/usb/etas_es58x/es58x_fd.h:231:6: note: while referencing 'raw_msg'
>   231 |   u8 raw_msg[0];
>       |      ^~~~~~~
> 
> Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Ayush Sawal <ayush.sawal@chelsio.com>
> Cc: Vinay Kumar Yadav <vinay.yadav@chelsio.com>
> Cc: Rohit Maheshwari <rohitm@chelsio.com>
> Cc: Herbert Xu <herbert@gondor.apana.org.au>
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: Kalle Valo <kvalo@codeaurora.org>
> Cc: Jakub Kicinski <kuba@kernel.org>
> Cc: Stanislaw Gruszka <stf_xl@wp.pl>
> Cc: Luca Coelho <luciano.coelho@intel.com>
> Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
> Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
> Cc: Alexei Starovoitov <ast@kernel.org>
> Cc: Daniel Borkmann <daniel@iogearbox.net>
> Cc: Andrii Nakryiko <andrii@kernel.org>
> Cc: Martin KaFai Lau <kafai@fb.com>
> Cc: Song Liu <songliubraving@fb.com>
> Cc: Yonghong Song <yhs@fb.com>
> Cc: John Fastabend <john.fastabend@gmail.com>
> Cc: KP Singh <kpsingh@kernel.org>
> Cc: Johannes Berg <johannes.berg@intel.com>
> Cc: Mordechay Goodstein <mordechay.goodstein@intel.com>
> Cc: Lee Jones <lee.jones@linaro.org>
> Cc: Wolfgang Grandegger <wg@grandegger.com>
> Cc: Marc Kleine-Budde <mkl@pengutronix.de>
> Cc: Arunachalam Santhanam <arunachalam.santhanam@in.bosch.com>
> Cc: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
> Cc: Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>
> Cc: linux-crypto@vger.kernel.org
> Cc: ath10k@lists.infradead.org
> Cc: linux-wireless@vger.kernel.org
> Cc: netdev@vger.kernel.org
> Cc: linux-scsi@vger.kernel.org
> Cc: linux-can@vger.kernel.org
> Cc: bpf@vger.kernel.org
> Signed-off-by: Kees Cook <keescook@chromium.org>
> ---
>  drivers/net/can/usb/etas_es58x/es581_4.h          |  2 +-
>  drivers/net/can/usb/etas_es58x/es58x_fd.h         |  2 +-

For the can drivers:

Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>

BTW: Is there opportunity for conversion, too?

| drivers/net/can/peak_canfd/peak_pciefd_main.c:146:32: warning: array of flexible structures

regards,
Marc
Vincent MAILHOL Aug. 26, 2021, 7:36 a.m. UTC | #2
On Thu. 26 Aug 2021 at 14:04, Kees Cook <keescook@chromium.org> wrote:
> In support of enabling -Warray-bounds and -Wzero-length-bounds and
> correctly handling run-time memcpy() bounds checking, replace all
> open-coded flexible arrays (i.e. 0-element arrays) in unions with the
> flex_array() helper macro.

Nitpick: the commit description says flex_array() but the code is
actually DECLARE_FLEX_ARRAY() or __DECLARE_FLEX_ARRAY().

> This fixes warnings such as:
>
> fs/hpfs/anode.c: In function 'hpfs_add_sector_to_btree':
> fs/hpfs/anode.c:209:27: warning: array subscript 0 is outside the bounds of an interior zero-length array 'struct bplus_internal_node[0]' [-Wzero-length-bounds]
>   209 |    anode->btree.u.internal[0].down = cpu_to_le32(a);
>       |    ~~~~~~~~~~~~~~~~~~~~~~~^~~
> In file included from fs/hpfs/hpfs_fn.h:26,
>                  from fs/hpfs/anode.c:10:
> fs/hpfs/hpfs.h:412:32: note: while referencing 'internal'
>   412 |     struct bplus_internal_node internal[0]; /* (internal) 2-word entries giving
>       |                                ^~~~~~~~
>
> drivers/net/can/usb/etas_es58x/es58x_fd.c: In function 'es58x_fd_tx_can_msg':
> drivers/net/can/usb/etas_es58x/es58x_fd.c:360:35: warning: array subscript 65535 is outside the bounds of an interior zero-length array 'u8[0]' {aka 'unsigned char[]'} [-Wzero-length-bounds]
>   360 |  tx_can_msg = (typeof(tx_can_msg))&es58x_fd_urb_cmd->raw_msg[msg_len];
>       |                                   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> In file included from drivers/net/can/usb/etas_es58x/es58x_core.h:22,
>                  from drivers/net/can/usb/etas_es58x/es58x_fd.c:17:
> drivers/net/can/usb/etas_es58x/es58x_fd.h:231:6: note: while referencing 'raw_msg'
>   231 |   u8 raw_msg[0];
>       |      ^~~~~~~
>
> Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Ayush Sawal <ayush.sawal@chelsio.com>
> Cc: Vinay Kumar Yadav <vinay.yadav@chelsio.com>
> Cc: Rohit Maheshwari <rohitm@chelsio.com>
> Cc: Herbert Xu <herbert@gondor.apana.org.au>
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: Kalle Valo <kvalo@codeaurora.org>
> Cc: Jakub Kicinski <kuba@kernel.org>
> Cc: Stanislaw Gruszka <stf_xl@wp.pl>
> Cc: Luca Coelho <luciano.coelho@intel.com>
> Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
> Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
> Cc: Alexei Starovoitov <ast@kernel.org>
> Cc: Daniel Borkmann <daniel@iogearbox.net>
> Cc: Andrii Nakryiko <andrii@kernel.org>
> Cc: Martin KaFai Lau <kafai@fb.com>
> Cc: Song Liu <songliubraving@fb.com>
> Cc: Yonghong Song <yhs@fb.com>
> Cc: John Fastabend <john.fastabend@gmail.com>
> Cc: KP Singh <kpsingh@kernel.org>
> Cc: Johannes Berg <johannes.berg@intel.com>
> Cc: Mordechay Goodstein <mordechay.goodstein@intel.com>
> Cc: Lee Jones <lee.jones@linaro.org>
> Cc: Wolfgang Grandegger <wg@grandegger.com>
> Cc: Marc Kleine-Budde <mkl@pengutronix.de>
> Cc: Arunachalam Santhanam <arunachalam.santhanam@in.bosch.com>
> Cc: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
> Cc: Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>
> Cc: linux-crypto@vger.kernel.org
> Cc: ath10k@lists.infradead.org
> Cc: linux-wireless@vger.kernel.org
> Cc: netdev@vger.kernel.org
> Cc: linux-scsi@vger.kernel.org
> Cc: linux-can@vger.kernel.org
> Cc: bpf@vger.kernel.org
> Signed-off-by: Kees Cook <keescook@chromium.org>
> ---
>  drivers/crypto/chelsio/chcr_crypto.h              | 14 +++++++++-----
>  drivers/net/can/usb/etas_es58x/es581_4.h          |  2 +-
>  drivers/net/can/usb/etas_es58x/es58x_fd.h         |  2 +-
>  drivers/net/wireless/ath/ath10k/htt.h             |  7 +++++--
>  drivers/net/wireless/intel/iwlegacy/commands.h    |  6 ++++--
>  drivers/net/wireless/intel/iwlwifi/dvm/commands.h |  6 ++++--
>  drivers/net/wireless/intel/iwlwifi/fw/api/tx.h    |  6 ++++--
>  drivers/scsi/aic94xx/aic94xx_sds.c                |  6 ++++--
>  fs/hpfs/hpfs.h                                    |  8 ++++----
>  include/linux/filter.h                            |  6 ++++--
>  include/scsi/sas.h                                | 12 ++++++++----
>  include/uapi/rdma/rdma_user_rxe.h                 |  4 ++--
>  include/uapi/sound/asoc.h                         |  4 ++--
>  13 files changed, 52 insertions(+), 31 deletions(-)
>
> diff --git a/drivers/crypto/chelsio/chcr_crypto.h b/drivers/crypto/chelsio/chcr_crypto.h
> index e89f9e0094b4..c7816c83e324 100644
> --- a/drivers/crypto/chelsio/chcr_crypto.h
> +++ b/drivers/crypto/chelsio/chcr_crypto.h
> @@ -222,8 +222,10 @@ struct chcr_authenc_ctx {
>  };
>
>  struct __aead_ctx {
> -       struct chcr_gcm_ctx gcm[0];
> -       struct chcr_authenc_ctx authenc[];
> +       union {
> +               DECLARE_FLEX_ARRAY(struct chcr_gcm_ctx, gcm);
> +               DECLARE_FLEX_ARRAY(struct chcr_authenc_ctx, authenc);
> +       };
>  };
>
>  struct chcr_aead_ctx {
> @@ -245,9 +247,11 @@ struct hmac_ctx {
>  };
>
>  struct __crypto_ctx {
> -       struct hmac_ctx hmacctx[0];
> -       struct ablk_ctx ablkctx[0];
> -       struct chcr_aead_ctx aeadctx[];
> +       union {
> +               DECLARE_FLEX_ARRAY(struct hmac_ctx, hmacctx);
> +               DECLARE_FLEX_ARRAY(struct ablk_ctx, ablkctx);
> +               DECLARE_FLEX_ARRAY(struct chcr_aead_ctx, aeadctx);
> +       };
>  };
>
>  struct chcr_context {
> diff --git a/drivers/net/can/usb/etas_es58x/es581_4.h b/drivers/net/can/usb/etas_es58x/es581_4.h
> index 4bc60a6df697..667ecb77168c 100644
> --- a/drivers/net/can/usb/etas_es58x/es581_4.h
> +++ b/drivers/net/can/usb/etas_es58x/es581_4.h
> @@ -192,7 +192,7 @@ struct es581_4_urb_cmd {
>                 struct es581_4_rx_cmd_ret rx_cmd_ret;
>                 __le64 timestamp;
>                 u8 rx_cmd_ret_u8;
> -               u8 raw_msg[0];
> +               DECLARE_FLEX_ARRAY(u8, raw_msg);
>         } __packed;
>
>         __le16 reserved_for_crc16_do_not_use;
> diff --git a/drivers/net/can/usb/etas_es58x/es58x_fd.h b/drivers/net/can/usb/etas_es58x/es58x_fd.h
> index ee18a87e40c0..e33003f96e5e 100644
> --- a/drivers/net/can/usb/etas_es58x/es58x_fd.h
> +++ b/drivers/net/can/usb/etas_es58x/es58x_fd.h
> @@ -228,7 +228,7 @@ struct es58x_fd_urb_cmd {
>                 struct es58x_fd_tx_ack_msg tx_ack_msg;
>                 __le64 timestamp;
>                 __le32 rx_cmd_ret_le32;
> -               u8 raw_msg[0];
> +               DECLARE_FLEX_ARRAY(u8, raw_msg);
>         } __packed;
>
>         __le16 reserved_for_crc16_do_not_use;
> diff --git a/drivers/net/wireless/ath/ath10k/htt.h b/drivers/net/wireless/ath/ath10k/htt.h
> index ec689e3ce48a..a6de08d3bf4a 100644
> --- a/drivers/net/wireless/ath/ath10k/htt.h
> +++ b/drivers/net/wireless/ath/ath10k/htt.h
> @@ -1674,8 +1674,11 @@ struct htt_tx_fetch_ind {
>         __le32 token;
>         __le16 num_resp_ids;
>         __le16 num_records;
> -       __le32 resp_ids[0]; /* ath10k_htt_get_tx_fetch_ind_resp_ids() */
> -       struct htt_tx_fetch_record records[];
> +       union {
> +               /* ath10k_htt_get_tx_fetch_ind_resp_ids() */
> +               DECLARE_FLEX_ARRAY(__le32, resp_ids);
> +               DECLARE_FLEX_ARRAY(struct htt_tx_fetch_record, records);
> +       };
>  } __packed;
>
>  static inline void *
> diff --git a/drivers/net/wireless/intel/iwlegacy/commands.h b/drivers/net/wireless/intel/iwlegacy/commands.h
> index 89c6671b32bc..4a97310f8fee 100644
> --- a/drivers/net/wireless/intel/iwlegacy/commands.h
> +++ b/drivers/net/wireless/intel/iwlegacy/commands.h
> @@ -1408,8 +1408,10 @@ struct il3945_tx_cmd {
>          * MAC header goes here, followed by 2 bytes padding if MAC header
>          * length is 26 or 30 bytes, followed by payload data
>          */
> -       u8 payload[0];
> -       struct ieee80211_hdr hdr[];
> +       union {
> +               DECLARE_FLEX_ARRAY(u8, payload);
> +               DECLARE_FLEX_ARRAY(struct ieee80211_hdr, hdr);
> +       };
>  } __packed;
>
>  /*
> diff --git a/drivers/net/wireless/intel/iwlwifi/dvm/commands.h b/drivers/net/wireless/intel/iwlwifi/dvm/commands.h
> index 235c7a2e3483..75a4b8e26232 100644
> --- a/drivers/net/wireless/intel/iwlwifi/dvm/commands.h
> +++ b/drivers/net/wireless/intel/iwlwifi/dvm/commands.h
> @@ -1251,8 +1251,10 @@ struct iwl_tx_cmd {
>          * MAC header goes here, followed by 2 bytes padding if MAC header
>          * length is 26 or 30 bytes, followed by payload data
>          */
> -       u8 payload[0];
> -       struct ieee80211_hdr hdr[];
> +       union {
> +               DECLARE_FLEX_ARRAY(u8, payload);
> +               DECLARE_FLEX_ARRAY(struct ieee80211_hdr, hdr);
> +       };
>  } __packed;
>
>  /*
> diff --git a/drivers/net/wireless/intel/iwlwifi/fw/api/tx.h b/drivers/net/wireless/intel/iwlwifi/fw/api/tx.h
> index 24e4a82a55da..66c5487e857e 100644
> --- a/drivers/net/wireless/intel/iwlwifi/fw/api/tx.h
> +++ b/drivers/net/wireless/intel/iwlwifi/fw/api/tx.h
> @@ -713,8 +713,10 @@ struct iwl_mvm_compressed_ba_notif {
>         __le32 tx_rate;
>         __le16 tfd_cnt;
>         __le16 ra_tid_cnt;
> -       struct iwl_mvm_compressed_ba_ratid ra_tid[0];
> -       struct iwl_mvm_compressed_ba_tfd tfd[];
> +       union {
> +               DECLARE_FLEX_ARRAY(struct iwl_mvm_compressed_ba_ratid, ra_tid);
> +               DECLARE_FLEX_ARRAY(struct iwl_mvm_compressed_ba_tfd, tfd);
> +       };
>  } __packed; /* COMPRESSED_BA_RES_API_S_VER_4 */
>
>  /**
> diff --git a/drivers/scsi/aic94xx/aic94xx_sds.c b/drivers/scsi/aic94xx/aic94xx_sds.c
> index 46815e65f7a4..5def83c88f13 100644
> --- a/drivers/scsi/aic94xx/aic94xx_sds.c
> +++ b/drivers/scsi/aic94xx/aic94xx_sds.c
> @@ -517,8 +517,10 @@ struct asd_ms_conn_map {
>         u8    num_nodes;
>         u8    usage_model_id;
>         u32   _resvd;
> -       struct asd_ms_conn_desc conn_desc[0];
> -       struct asd_ms_node_desc node_desc[];
> +       union {
> +               DECLARE_FLEX_ARRAY(struct asd_ms_conn_desc, conn_desc);
> +               DECLARE_FLEX_ARRAY(struct asd_ms_node_desc, node_desc);
> +       };
>  } __attribute__ ((packed));
>
>  struct asd_ctrla_phy_entry {
> diff --git a/fs/hpfs/hpfs.h b/fs/hpfs/hpfs.h
> index d92c4af3e1b4..281dec8f636b 100644
> --- a/fs/hpfs/hpfs.h
> +++ b/fs/hpfs/hpfs.h
> @@ -409,10 +409,10 @@ struct bplus_header
>    __le16 first_free;                   /* offset from start of header to
>                                            first free node in array */
>    union {
> -    struct bplus_internal_node internal[0]; /* (internal) 2-word entries giving
> -                                              subtree pointers */
> -    struct bplus_leaf_node external[0];            /* (external) 3-word entries giving
> -                                              sector runs */
> +       /* (internal) 2-word entries giving subtree pointers */
> +       DECLARE_FLEX_ARRAY(struct bplus_internal_node, internal);
> +       /* (external) 3-word entries giving sector runs */
> +       DECLARE_FLEX_ARRAY(struct bplus_leaf_node, external);
>    } u;
>  };
>
> diff --git a/include/linux/filter.h b/include/linux/filter.h
> index 472f97074da0..5ca52bfa5868 100644
> --- a/include/linux/filter.h
> +++ b/include/linux/filter.h
> @@ -572,8 +572,10 @@ struct bpf_prog {
>         struct bpf_prog_aux     *aux;           /* Auxiliary fields */
>         struct sock_fprog_kern  *orig_prog;     /* Original BPF program */
>         /* Instructions for interpreter */
> -       struct sock_filter      insns[0];
> -       struct bpf_insn         insnsi[];
> +       union {
> +               DECLARE_FLEX_ARRAY(struct sock_filter, insns);
> +               DECLARE_FLEX_ARRAY(struct bpf_insn, insnsi);
> +       };
>  };
>
>  struct sk_filter {
> diff --git a/include/scsi/sas.h b/include/scsi/sas.h
> index 4726c1bbec65..64154c1fed02 100644
> --- a/include/scsi/sas.h
> +++ b/include/scsi/sas.h
> @@ -323,8 +323,10 @@ struct ssp_response_iu {
>         __be32 sense_data_len;
>         __be32 response_data_len;
>
> -       u8     resp_data[0];
> -       u8     sense_data[];
> +       union {
> +               DECLARE_FLEX_ARRAY(u8, resp_data);
> +               DECLARE_FLEX_ARRAY(u8, sense_data);
> +       };
>  } __attribute__ ((packed));
>
>  struct ssp_command_iu {
> @@ -554,8 +556,10 @@ struct ssp_response_iu {
>         __be32 sense_data_len;
>         __be32 response_data_len;
>
> -       u8     resp_data[0];
> -       u8     sense_data[];
> +       union {
> +               DECLARE_FLEX_ARRAY(u8, resp_data);
> +               DECLARE_FLEX_ARRAY(u8, sense_data);
> +       };
>  } __attribute__ ((packed));
>
>  struct ssp_command_iu {
> diff --git a/include/uapi/rdma/rdma_user_rxe.h b/include/uapi/rdma/rdma_user_rxe.h
> index e283c2220aba..040752c99ec9 100644
> --- a/include/uapi/rdma/rdma_user_rxe.h
> +++ b/include/uapi/rdma/rdma_user_rxe.h
> @@ -141,8 +141,8 @@ struct rxe_dma_info {
>         __u32                   sge_offset;
>         __u32                   reserved;
>         union {
> -               __u8            inline_data[0];
> -               struct rxe_sge  sge[0];
> +               __DECLARE_FLEX_ARRAY(u8, inline_data);
> +               __DECLARE_FLEX_ARRAY(struct rxe_sge, sge);
>         };
>  };
>
> diff --git a/include/uapi/sound/asoc.h b/include/uapi/sound/asoc.h
> index da61398b1f8f..053949287ce8 100644
> --- a/include/uapi/sound/asoc.h
> +++ b/include/uapi/sound/asoc.h
> @@ -240,8 +240,8 @@ struct snd_soc_tplg_vendor_array {
>  struct snd_soc_tplg_private {
>         __le32 size;    /* in bytes of private data */
>         union {
> -               char data[0];
> -               struct snd_soc_tplg_vendor_array array[0];
> +               __DECLARE_FLEX_ARRAY(char, data);
> +               __DECLARE_FLEX_ARRAY(struct snd_soc_tplg_vendor_array, array);
>         };
>  } __attribute__((packed));
>
> --
> 2.30.2
>
Kees Cook Aug. 26, 2021, 3:39 p.m. UTC | #3
On August 26, 2021 12:36:27 AM PDT, Vincent MAILHOL <mailhol.vincent@wanadoo.fr> wrote:
>On Thu. 26 Aug 2021 at 14:04, Kees Cook <keescook@chromium.org> wrote:
>> In support of enabling -Warray-bounds and -Wzero-length-bounds and
>> correctly handling run-time memcpy() bounds checking, replace all
>> open-coded flexible arrays (i.e. 0-element arrays) in unions with the
>> flex_array() helper macro.
>
>Nitpick: the commit description says flex_array() but the code is
>actually DECLARE_FLEX_ARRAY() or __DECLARE_FLEX_ARRAY().

Ah yes, thanks! I had renamed the macro but missed these references. Now fixed!

-Kees
Kees Cook Aug. 27, 2021, 4:08 p.m. UTC | #4
On Thu, Aug 26, 2021 at 08:24:52AM +0200, Marc Kleine-Budde wrote:
> On 25.08.2021 22:04:55, Kees Cook wrote:
> > In support of enabling -Warray-bounds and -Wzero-length-bounds and
> > correctly handling run-time memcpy() bounds checking, replace all
> > open-coded flexible arrays (i.e. 0-element arrays) in unions with the
> > flex_array() helper macro.
> > 
> > This fixes warnings such as:
> > 
> > fs/hpfs/anode.c: In function 'hpfs_add_sector_to_btree':
> > fs/hpfs/anode.c:209:27: warning: array subscript 0 is outside the bounds of an interior zero-length array 'struct bplus_internal_node[0]' [-Wzero-length-bounds]
> >   209 |    anode->btree.u.internal[0].down = cpu_to_le32(a);
> >       |    ~~~~~~~~~~~~~~~~~~~~~~~^~~
> > In file included from fs/hpfs/hpfs_fn.h:26,
> >                  from fs/hpfs/anode.c:10:
> > fs/hpfs/hpfs.h:412:32: note: while referencing 'internal'
> >   412 |     struct bplus_internal_node internal[0]; /* (internal) 2-word entries giving
> >       |                                ^~~~~~~~
> > 
> > drivers/net/can/usb/etas_es58x/es58x_fd.c: In function 'es58x_fd_tx_can_msg':
> > drivers/net/can/usb/etas_es58x/es58x_fd.c:360:35: warning: array subscript 65535 is outside the bounds of an interior zero-length array 'u8[0]' {aka 'unsigned char[]'} [-Wzero-length-bounds]
> >   360 |  tx_can_msg = (typeof(tx_can_msg))&es58x_fd_urb_cmd->raw_msg[msg_len];
> >       |                                   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > In file included from drivers/net/can/usb/etas_es58x/es58x_core.h:22,
> >                  from drivers/net/can/usb/etas_es58x/es58x_fd.c:17:
> > drivers/net/can/usb/etas_es58x/es58x_fd.h:231:6: note: while referencing 'raw_msg'
> >   231 |   u8 raw_msg[0];
> >       |      ^~~~~~~
> > 
> > Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org>
> > Cc: Arnd Bergmann <arnd@arndb.de>
> > Cc: Ayush Sawal <ayush.sawal@chelsio.com>
> > Cc: Vinay Kumar Yadav <vinay.yadav@chelsio.com>
> > Cc: Rohit Maheshwari <rohitm@chelsio.com>
> > Cc: Herbert Xu <herbert@gondor.apana.org.au>
> > Cc: "David S. Miller" <davem@davemloft.net>
> > Cc: Kalle Valo <kvalo@codeaurora.org>
> > Cc: Jakub Kicinski <kuba@kernel.org>
> > Cc: Stanislaw Gruszka <stf_xl@wp.pl>
> > Cc: Luca Coelho <luciano.coelho@intel.com>
> > Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
> > Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
> > Cc: Alexei Starovoitov <ast@kernel.org>
> > Cc: Daniel Borkmann <daniel@iogearbox.net>
> > Cc: Andrii Nakryiko <andrii@kernel.org>
> > Cc: Martin KaFai Lau <kafai@fb.com>
> > Cc: Song Liu <songliubraving@fb.com>
> > Cc: Yonghong Song <yhs@fb.com>
> > Cc: John Fastabend <john.fastabend@gmail.com>
> > Cc: KP Singh <kpsingh@kernel.org>
> > Cc: Johannes Berg <johannes.berg@intel.com>
> > Cc: Mordechay Goodstein <mordechay.goodstein@intel.com>
> > Cc: Lee Jones <lee.jones@linaro.org>
> > Cc: Wolfgang Grandegger <wg@grandegger.com>
> > Cc: Marc Kleine-Budde <mkl@pengutronix.de>
> > Cc: Arunachalam Santhanam <arunachalam.santhanam@in.bosch.com>
> > Cc: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
> > Cc: Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>
> > Cc: linux-crypto@vger.kernel.org
> > Cc: ath10k@lists.infradead.org
> > Cc: linux-wireless@vger.kernel.org
> > Cc: netdev@vger.kernel.org
> > Cc: linux-scsi@vger.kernel.org
> > Cc: linux-can@vger.kernel.org
> > Cc: bpf@vger.kernel.org
> > Signed-off-by: Kees Cook <keescook@chromium.org>
> > ---
> >  drivers/net/can/usb/etas_es58x/es581_4.h          |  2 +-
> >  drivers/net/can/usb/etas_es58x/es58x_fd.h         |  2 +-
> 
> For the can drivers:
> 
> Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>

Thanks!

> BTW: Is there opportunity for conversion, too?
> 
> | drivers/net/can/peak_canfd/peak_pciefd_main.c:146:32: warning: array of flexible structures

Oh, hrmpf. This isn't a sane use of flex arrays:


struct __packed pucan_rx_msg {
	...
	__le32	can_id;
	u8	d[];
};

struct pciefd_rx_dma {
        __le32 irq_status;
        __le32 sys_time_low;
        __le32 sys_time_high;
        struct pucan_rx_msg msg[];
} __packed __aligned(4);

I think that needs to be handled separately. How are you building to get
that warning, by the way? I haven't seen that in my builds...
Kees Cook Aug. 27, 2021, 4:17 p.m. UTC | #5
On Thu, Aug 26, 2021 at 08:24:52AM +0200, Marc Kleine-Budde wrote:
> [...]
> BTW: Is there opportunity for conversion, too?
> 
> | drivers/net/can/peak_canfd/peak_pciefd_main.c:146:32: warning: array of flexible structures

Untested potential solution:

diff --git a/drivers/net/can/peak_canfd/peak_pciefd_main.c b/drivers/net/can/peak_canfd/peak_pciefd_main.c
index 1df3c4b54f03..efa2b5a52bd7 100644
--- a/drivers/net/can/peak_canfd/peak_pciefd_main.c
+++ b/drivers/net/can/peak_canfd/peak_pciefd_main.c
@@ -143,7 +143,11 @@ struct pciefd_rx_dma {
 	__le32 irq_status;
 	__le32 sys_time_low;
 	__le32 sys_time_high;
-	struct pucan_rx_msg msg[];
+	/*
+	 * with "msg" being pciefd_irq_rx_cnt(priv->irq_status)-many
+	 * variable-sized struct pucan_rx_msg following.
+	 */
+	__le32 msg[];
 } __packed __aligned(4);
 
 /* Tx Link record */
@@ -327,7 +331,7 @@ static irqreturn_t pciefd_irq_handler(int irq, void *arg)
 
 	/* handle rx messages (if any) */
 	peak_canfd_handle_msgs_list(&priv->ucan,
-				    rx_dma->msg,
+				    (struct pucan_rx_msg *)rx_dma->msg,
 				    pciefd_irq_rx_cnt(priv->irq_status));
 
 	/* handle tx link interrupt (if any) */


It's not great, but it's also not strictly a flex array, in the sense
that since struct pucan_rx_msg is a variable size, the compiler cannot
reason about the size of struct pciefd_rx_dma based only on the
irq_status encoding...
Marc Kleine-Budde Aug. 27, 2021, 5:08 p.m. UTC | #6
On 27.08.2021 09:08:19, Kees Cook wrote:
> > BTW: Is there opportunity for conversion, too?
> > 
> > | drivers/net/can/peak_canfd/peak_pciefd_main.c:146:32: warning: array of flexible structures
> 
> Oh, hrmpf. This isn't a sane use of flex arrays:
> 
> struct __packed pucan_rx_msg {
> 	...
> 	__le32	can_id;
> 	u8	d[];
> };
> 
> struct pciefd_rx_dma {
>         __le32 irq_status;
>         __le32 sys_time_low;
>         __le32 sys_time_high;
>         struct pucan_rx_msg msg[];
> } __packed __aligned(4);
> 
> I think that needs to be handled separately. How are you building to get
> that warning, by the way? I haven't seen that in my builds...

If compiling with C=1, sparse will complain about this.

regards,
Marc
Vincent MAILHOL Aug. 28, 2021, 7:31 a.m. UTC | #7
Le sam. 28 août 2021 à 01:17, Kees Cook <keescook@chromium.org> a écrit :
>
> On Thu, Aug 26, 2021 at 08:24:52AM +0200, Marc Kleine-Budde wrote:
> > [...]
> > BTW: Is there opportunity for conversion, too?
> >
> > | drivers/net/can/peak_canfd/peak_pciefd_main.c:146:32: warning: array of flexible structures
>
> Untested potential solution:
>
> diff --git a/drivers/net/can/peak_canfd/peak_pciefd_main.c b/drivers/net/can/peak_canfd/peak_pciefd_main.c
> index 1df3c4b54f03..efa2b5a52bd7 100644
> --- a/drivers/net/can/peak_canfd/peak_pciefd_main.c
> +++ b/drivers/net/can/peak_canfd/peak_pciefd_main.c
> @@ -143,7 +143,11 @@ struct pciefd_rx_dma {
>         __le32 irq_status;
>         __le32 sys_time_low;
>         __le32 sys_time_high;
> -       struct pucan_rx_msg msg[];
> +       /*
> +        * with "msg" being pciefd_irq_rx_cnt(priv->irq_status)-many
> +        * variable-sized struct pucan_rx_msg following.
> +        */
> +       __le32 msg[];

Isn't u8 msg[] preferable here?

>  } __packed __aligned(4);
>
>  /* Tx Link record */
> @@ -327,7 +331,7 @@ static irqreturn_t pciefd_irq_handler(int irq, void *arg)
>
>         /* handle rx messages (if any) */
>         peak_canfd_handle_msgs_list(&priv->ucan,
> -                                   rx_dma->msg,
> +                                   (struct pucan_rx_msg *)rx_dma->msg,
>                                     pciefd_irq_rx_cnt(priv->irq_status));
>
>         /* handle tx link interrupt (if any) */
>
>
> It's not great, but it's also not strictly a flex array, in the sense
> that since struct pucan_rx_msg is a variable size, the compiler cannot
> reason about the size of struct pciefd_rx_dma based only on the
> irq_status encoding...

In the same spirit, it is a bit cleaner to change the prototype of
handle_msgs_list().

Like that:


diff --git a/drivers/net/can/peak_canfd/peak_canfd.c b/drivers/net/can/peak_canf
d/peak_canfd.c
index d08718e98e11..81a9faa6193f 100644
--- a/drivers/net/can/peak_canfd/peak_canfd.c
+++ b/drivers/net/can/peak_canfd/peak_canfd.c
@@ -484,9 +484,8 @@ int peak_canfd_handle_msg(struct peak_canfd_priv *priv,

 /* handle a list of rx_count messages from rx_msg memory address */
 int peak_canfd_handle_msgs_list(struct peak_canfd_priv *priv,
-                               struct pucan_rx_msg *msg_list, int msg_count)
+                               void *msg_ptr, int msg_count)
 {
-       void *msg_ptr = msg_list;
        int i, msg_size = 0;

        for (i = 0; i < msg_count; i++) {
diff --git a/drivers/net/can/peak_canfd/peak_canfd_user.h b/drivers/net/can/peak
_canfd/peak_canfd_user.h
index a72719dc3b74..ef91f92e70c3 100644
--- a/drivers/net/can/peak_canfd/peak_canfd_user.h
+++ b/drivers/net/can/peak_canfd/peak_canfd_user.h
@@ -42,5 +42,5 @@ struct net_device *alloc_peak_canfd_dev(int
sizeof_priv, int index,
 int peak_canfd_handle_msg(struct peak_canfd_priv *priv,
                          struct pucan_rx_msg *msg);
 int peak_canfd_handle_msgs_list(struct peak_canfd_priv *priv,
-                               struct pucan_rx_msg *rx_msg, int rx_count);
+                               void *msg_ptr, int rx_count);
 #endif
diff --git a/drivers/net/can/peak_canfd/peak_pciefd_main.c
b/drivers/net/can/peak_canfd/peak_pciefd_main.c
index 1df3c4b54f03..c1de1e3dc4bc 100644
--- a/drivers/net/can/peak_canfd/peak_pciefd_main.c
+++ b/drivers/net/can/peak_canfd/peak_pciefd_main.c
@@ -143,7 +143,11 @@ struct pciefd_rx_dma {
        __le32 irq_status;
        __le32 sys_time_low;
        __le32 sys_time_high;
-       struct pucan_rx_msg msg[];
+       /*
+        * with "msg" being pciefd_irq_rx_cnt(priv->irq_status)-many
+        * variable-sized struct pucan_rx_msg following.
+        */
+       u8 msg[];
 } __packed __aligned(4);

 /* Tx Link record */


Another solution would be to declare a maximum length for struct
pucan_rx_msg::d. Because these are CAN FD messages, I suppose
that maximum length would be CANFD_MAX_DLEN. struct canfd_frame
from the UAPI uses the same pattern.

N.B. This solution is not exclusive from the above one (actually,
I think that using both would be the best solution).

diff --git a/include/linux/can/dev/peak_canfd.h
b/include/linux/can/dev/peak_canfd.h
index f38772fd0c07..a048359db430 100644
--- a/include/linux/can/dev/peak_canfd.h
+++ b/include/linux/can/dev/peak_canfd.h
@@ -189,7 +189,7 @@ struct __packed pucan_rx_msg {
        u8      client;
        __le16  flags;
        __le32  can_id;
-       u8      d[];
+       u8      d[CANFD_MAX_DLEN];
 };

 /* uCAN error types */



I only tested for compilation.

Yours sincerely,
Vincent
diff mbox series

Patch

diff --git a/drivers/crypto/chelsio/chcr_crypto.h b/drivers/crypto/chelsio/chcr_crypto.h
index e89f9e0094b4..c7816c83e324 100644
--- a/drivers/crypto/chelsio/chcr_crypto.h
+++ b/drivers/crypto/chelsio/chcr_crypto.h
@@ -222,8 +222,10 @@  struct chcr_authenc_ctx {
 };
 
 struct __aead_ctx {
-	struct chcr_gcm_ctx gcm[0];
-	struct chcr_authenc_ctx authenc[];
+	union {
+		DECLARE_FLEX_ARRAY(struct chcr_gcm_ctx, gcm);
+		DECLARE_FLEX_ARRAY(struct chcr_authenc_ctx, authenc);
+	};
 };
 
 struct chcr_aead_ctx {
@@ -245,9 +247,11 @@  struct hmac_ctx {
 };
 
 struct __crypto_ctx {
-	struct hmac_ctx hmacctx[0];
-	struct ablk_ctx ablkctx[0];
-	struct chcr_aead_ctx aeadctx[];
+	union {
+		DECLARE_FLEX_ARRAY(struct hmac_ctx, hmacctx);
+		DECLARE_FLEX_ARRAY(struct ablk_ctx, ablkctx);
+		DECLARE_FLEX_ARRAY(struct chcr_aead_ctx, aeadctx);
+	};
 };
 
 struct chcr_context {
diff --git a/drivers/net/can/usb/etas_es58x/es581_4.h b/drivers/net/can/usb/etas_es58x/es581_4.h
index 4bc60a6df697..667ecb77168c 100644
--- a/drivers/net/can/usb/etas_es58x/es581_4.h
+++ b/drivers/net/can/usb/etas_es58x/es581_4.h
@@ -192,7 +192,7 @@  struct es581_4_urb_cmd {
 		struct es581_4_rx_cmd_ret rx_cmd_ret;
 		__le64 timestamp;
 		u8 rx_cmd_ret_u8;
-		u8 raw_msg[0];
+		DECLARE_FLEX_ARRAY(u8, raw_msg);
 	} __packed;
 
 	__le16 reserved_for_crc16_do_not_use;
diff --git a/drivers/net/can/usb/etas_es58x/es58x_fd.h b/drivers/net/can/usb/etas_es58x/es58x_fd.h
index ee18a87e40c0..e33003f96e5e 100644
--- a/drivers/net/can/usb/etas_es58x/es58x_fd.h
+++ b/drivers/net/can/usb/etas_es58x/es58x_fd.h
@@ -228,7 +228,7 @@  struct es58x_fd_urb_cmd {
 		struct es58x_fd_tx_ack_msg tx_ack_msg;
 		__le64 timestamp;
 		__le32 rx_cmd_ret_le32;
-		u8 raw_msg[0];
+		DECLARE_FLEX_ARRAY(u8, raw_msg);
 	} __packed;
 
 	__le16 reserved_for_crc16_do_not_use;
diff --git a/drivers/net/wireless/ath/ath10k/htt.h b/drivers/net/wireless/ath/ath10k/htt.h
index ec689e3ce48a..a6de08d3bf4a 100644
--- a/drivers/net/wireless/ath/ath10k/htt.h
+++ b/drivers/net/wireless/ath/ath10k/htt.h
@@ -1674,8 +1674,11 @@  struct htt_tx_fetch_ind {
 	__le32 token;
 	__le16 num_resp_ids;
 	__le16 num_records;
-	__le32 resp_ids[0]; /* ath10k_htt_get_tx_fetch_ind_resp_ids() */
-	struct htt_tx_fetch_record records[];
+	union {
+		/* ath10k_htt_get_tx_fetch_ind_resp_ids() */
+		DECLARE_FLEX_ARRAY(__le32, resp_ids);
+		DECLARE_FLEX_ARRAY(struct htt_tx_fetch_record, records);
+	};
 } __packed;
 
 static inline void *
diff --git a/drivers/net/wireless/intel/iwlegacy/commands.h b/drivers/net/wireless/intel/iwlegacy/commands.h
index 89c6671b32bc..4a97310f8fee 100644
--- a/drivers/net/wireless/intel/iwlegacy/commands.h
+++ b/drivers/net/wireless/intel/iwlegacy/commands.h
@@ -1408,8 +1408,10 @@  struct il3945_tx_cmd {
 	 * MAC header goes here, followed by 2 bytes padding if MAC header
 	 * length is 26 or 30 bytes, followed by payload data
 	 */
-	u8 payload[0];
-	struct ieee80211_hdr hdr[];
+	union {
+		DECLARE_FLEX_ARRAY(u8, payload);
+		DECLARE_FLEX_ARRAY(struct ieee80211_hdr, hdr);
+	};
 } __packed;
 
 /*
diff --git a/drivers/net/wireless/intel/iwlwifi/dvm/commands.h b/drivers/net/wireless/intel/iwlwifi/dvm/commands.h
index 235c7a2e3483..75a4b8e26232 100644
--- a/drivers/net/wireless/intel/iwlwifi/dvm/commands.h
+++ b/drivers/net/wireless/intel/iwlwifi/dvm/commands.h
@@ -1251,8 +1251,10 @@  struct iwl_tx_cmd {
 	 * MAC header goes here, followed by 2 bytes padding if MAC header
 	 * length is 26 or 30 bytes, followed by payload data
 	 */
-	u8 payload[0];
-	struct ieee80211_hdr hdr[];
+	union {
+		DECLARE_FLEX_ARRAY(u8, payload);
+		DECLARE_FLEX_ARRAY(struct ieee80211_hdr, hdr);
+	};
 } __packed;
 
 /*
diff --git a/drivers/net/wireless/intel/iwlwifi/fw/api/tx.h b/drivers/net/wireless/intel/iwlwifi/fw/api/tx.h
index 24e4a82a55da..66c5487e857e 100644
--- a/drivers/net/wireless/intel/iwlwifi/fw/api/tx.h
+++ b/drivers/net/wireless/intel/iwlwifi/fw/api/tx.h
@@ -713,8 +713,10 @@  struct iwl_mvm_compressed_ba_notif {
 	__le32 tx_rate;
 	__le16 tfd_cnt;
 	__le16 ra_tid_cnt;
-	struct iwl_mvm_compressed_ba_ratid ra_tid[0];
-	struct iwl_mvm_compressed_ba_tfd tfd[];
+	union {
+		DECLARE_FLEX_ARRAY(struct iwl_mvm_compressed_ba_ratid, ra_tid);
+		DECLARE_FLEX_ARRAY(struct iwl_mvm_compressed_ba_tfd, tfd);
+	};
 } __packed; /* COMPRESSED_BA_RES_API_S_VER_4 */
 
 /**
diff --git a/drivers/scsi/aic94xx/aic94xx_sds.c b/drivers/scsi/aic94xx/aic94xx_sds.c
index 46815e65f7a4..5def83c88f13 100644
--- a/drivers/scsi/aic94xx/aic94xx_sds.c
+++ b/drivers/scsi/aic94xx/aic94xx_sds.c
@@ -517,8 +517,10 @@  struct asd_ms_conn_map {
 	u8    num_nodes;
 	u8    usage_model_id;
 	u32   _resvd;
-	struct asd_ms_conn_desc conn_desc[0];
-	struct asd_ms_node_desc node_desc[];
+	union {
+		DECLARE_FLEX_ARRAY(struct asd_ms_conn_desc, conn_desc);
+		DECLARE_FLEX_ARRAY(struct asd_ms_node_desc, node_desc);
+	};
 } __attribute__ ((packed));
 
 struct asd_ctrla_phy_entry {
diff --git a/fs/hpfs/hpfs.h b/fs/hpfs/hpfs.h
index d92c4af3e1b4..281dec8f636b 100644
--- a/fs/hpfs/hpfs.h
+++ b/fs/hpfs/hpfs.h
@@ -409,10 +409,10 @@  struct bplus_header
   __le16 first_free;			/* offset from start of header to
 					   first free node in array */
   union {
-    struct bplus_internal_node internal[0]; /* (internal) 2-word entries giving
-					       subtree pointers */
-    struct bplus_leaf_node external[0];	    /* (external) 3-word entries giving
-					       sector runs */
+	/* (internal) 2-word entries giving subtree pointers */
+	DECLARE_FLEX_ARRAY(struct bplus_internal_node, internal);
+	/* (external) 3-word entries giving sector runs */
+	DECLARE_FLEX_ARRAY(struct bplus_leaf_node, external);
   } u;
 };
 
diff --git a/include/linux/filter.h b/include/linux/filter.h
index 472f97074da0..5ca52bfa5868 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -572,8 +572,10 @@  struct bpf_prog {
 	struct bpf_prog_aux	*aux;		/* Auxiliary fields */
 	struct sock_fprog_kern	*orig_prog;	/* Original BPF program */
 	/* Instructions for interpreter */
-	struct sock_filter	insns[0];
-	struct bpf_insn		insnsi[];
+	union {
+		DECLARE_FLEX_ARRAY(struct sock_filter, insns);
+		DECLARE_FLEX_ARRAY(struct bpf_insn, insnsi);
+	};
 };
 
 struct sk_filter {
diff --git a/include/scsi/sas.h b/include/scsi/sas.h
index 4726c1bbec65..64154c1fed02 100644
--- a/include/scsi/sas.h
+++ b/include/scsi/sas.h
@@ -323,8 +323,10 @@  struct ssp_response_iu {
 	__be32 sense_data_len;
 	__be32 response_data_len;
 
-	u8     resp_data[0];
-	u8     sense_data[];
+	union {
+		DECLARE_FLEX_ARRAY(u8, resp_data);
+		DECLARE_FLEX_ARRAY(u8, sense_data);
+	};
 } __attribute__ ((packed));
 
 struct ssp_command_iu {
@@ -554,8 +556,10 @@  struct ssp_response_iu {
 	__be32 sense_data_len;
 	__be32 response_data_len;
 
-	u8     resp_data[0];
-	u8     sense_data[];
+	union {
+		DECLARE_FLEX_ARRAY(u8, resp_data);
+		DECLARE_FLEX_ARRAY(u8, sense_data);
+	};
 } __attribute__ ((packed));
 
 struct ssp_command_iu {
diff --git a/include/uapi/rdma/rdma_user_rxe.h b/include/uapi/rdma/rdma_user_rxe.h
index e283c2220aba..040752c99ec9 100644
--- a/include/uapi/rdma/rdma_user_rxe.h
+++ b/include/uapi/rdma/rdma_user_rxe.h
@@ -141,8 +141,8 @@  struct rxe_dma_info {
 	__u32			sge_offset;
 	__u32			reserved;
 	union {
-		__u8		inline_data[0];
-		struct rxe_sge	sge[0];
+		__DECLARE_FLEX_ARRAY(u8, inline_data);
+		__DECLARE_FLEX_ARRAY(struct rxe_sge, sge);
 	};
 };
 
diff --git a/include/uapi/sound/asoc.h b/include/uapi/sound/asoc.h
index da61398b1f8f..053949287ce8 100644
--- a/include/uapi/sound/asoc.h
+++ b/include/uapi/sound/asoc.h
@@ -240,8 +240,8 @@  struct snd_soc_tplg_vendor_array {
 struct snd_soc_tplg_private {
 	__le32 size;	/* in bytes of private data */
 	union {
-		char data[0];
-		struct snd_soc_tplg_vendor_array array[0];
+		__DECLARE_FLEX_ARRAY(char, data);
+		__DECLARE_FLEX_ARRAY(struct snd_soc_tplg_vendor_array, array);
 	};
 } __attribute__((packed));