Re: [PATCH 09/10][next] scsi: aacraid: Replace one-element array with flexible-array member in struct sgmap64

Kees Cook
2023-06-28T20:46:43Z

On Wed, Jun 28, 2023 at 11:57:30AM -0600, Gustavo A. R. Silva wrote:
> Replace one-element array with flexible-array member in struct
> sgmap64 and refactor the rest of the code, accordingly.
>
> Issue found with the help of Coccinelle and audited and fixed,
> manually.

Like with the sgmap patch, I see (expected) binary differences in
aac_write_block64() and aac_read_block64() due to the simplified
calculations. I don't see anything unaccounted for, so:

Reviewed-by: Kees Cook <keescook@chromium.org>

-Kees

> Link: https://github.com/KSPP/linux/issues/79
> Link: https://github.com/ClangBuiltLinux/linux/issues/1851
> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
> ---
> drivers/scsi/aacraid/aachba.c | 9 +++------
> drivers/scsi/aacraid/aacraid.h | 2 +-
> 2 files changed, 4 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/scsi/aacraid/aachba.c b/drivers/scsi/aacraid/aachba.c
> index b2849e5cc104..90df697e7c5f 100644
> --- a/drivers/scsi/aacraid/aachba.c
> +++ b/drivers/scsi/aacraid/aachba.c
> @@ -1301,8 +1301,7 @@ static int aac_read_block64(struct fib * fib, struct scsi_cmnd * cmd, u64 lba, u
> if (ret < 0)
> return ret;
> fibsize = sizeof(struct aac_read64) +
> - ((le32_to_cpu(readcmd->sg.count) - 1) *
> - sizeof (struct sgentry64));
> + le32_to_cpu(readcmd->sg.count) * sizeof(struct sgentry64);
> BUG_ON (fibsize > (fib->dev->max_fib_size -
> sizeof(struct aac_fibhdr)));
> /*
> @@ -1433,8 +1432,7 @@ static int aac_write_block64(struct fib * fib, struct scsi_cmnd * cmd, u64 lba,
> if (ret < 0)
> return ret;
> fibsize = sizeof(struct aac_write64) +
> - ((le32_to_cpu(writecmd->sg.count) - 1) *
> - sizeof (struct sgentry64));
> + le32_to_cpu(writecmd->sg.count) * sizeof(struct sgentry64);
> BUG_ON (fibsize > (fib->dev->max_fib_size -
> sizeof(struct aac_fibhdr)));
> /*
> @@ -2271,8 +2269,7 @@ int aac_get_adapter_info(struct aac_dev* dev)
> dev->scsi_host_ptr->sg_tablesize =
> (dev->max_fib_size -
> sizeof(struct aac_fibhdr) -
> - sizeof(struct aac_write64) +
> - sizeof(struct sgentry64)) /
> + sizeof(struct aac_write64)) /
> sizeof(struct sgentry64);
> } else {
> dev->a_ops.adapter_read = aac_read_block;
> diff --git a/drivers/scsi/aacraid/aacraid.h b/drivers/scsi/aacraid/aacraid.h
> index 3fbc22ae72b6..fb3d93e4a99e 100644
> --- a/drivers/scsi/aacraid/aacraid.h
> +++ b/drivers/scsi/aacraid/aacraid.h
> @@ -517,7 +517,7 @@ struct user_sgmap {
>
> struct sgmap64 {
> __le32 count;
> - struct sgentry64 sg[1];
> + struct sgentry64 sg[];
> };
>
> struct user_sgmap64 {
> --
> 2.34.1
>

--
Kees Cook