Re: [PATCH 05/10][next] scsi: aacraid: Replace one-element array with flexible-array member in struct sgmapraw

From: Kees Cook
Date: Wed Jun 28 2023 - 16:50:05 EST


On Wed, Jun 28, 2023 at 11:56:12AM -0600, Gustavo A. R. Silva wrote:
> Replace one-element array with flexible-array member in struct
> sgmapraw.
>
> Issue found with the help of Coccinelle and audited and fixed,
> manually.

As with the other two, I see expected binary changes in
aac_read_raw_io() and aac_write_raw_io() due to the simplified count
calculations.

Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>

-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@xxxxxxxxxx>
> ---
> drivers/scsi/aacraid/aachba.c | 4 ++--
> drivers/scsi/aacraid/aacraid.h | 2 +-
> 2 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/scsi/aacraid/aachba.c b/drivers/scsi/aacraid/aachba.c
> index fff0550e02e4..b3c0c2255e55 100644
> --- a/drivers/scsi/aacraid/aachba.c
> +++ b/drivers/scsi/aacraid/aachba.c
> @@ -1267,7 +1267,7 @@ static int aac_read_raw_io(struct fib * fib, struct scsi_cmnd * cmd, u64 lba, u3
> return ret;
> command = ContainerRawIo;
> fibsize = sizeof(struct aac_raw_io) +
> - ((le32_to_cpu(readcmd->sg.count)-1) * sizeof(struct sgentryraw));
> + le32_to_cpu(readcmd->sg.count) * sizeof(struct sgentryraw);
> }
>
> BUG_ON(fibsize > (fib->dev->max_fib_size - sizeof(struct aac_fibhdr)));
> @@ -1401,7 +1401,7 @@ static int aac_write_raw_io(struct fib * fib, struct scsi_cmnd * cmd, u64 lba, u
> return ret;
> command = ContainerRawIo;
> fibsize = sizeof(struct aac_raw_io) +
> - ((le32_to_cpu(writecmd->sg.count)-1) * sizeof (struct sgentryraw));
> + le32_to_cpu(writecmd->sg.count) * sizeof(struct sgentryraw);
> }
>
> BUG_ON(fibsize > (fib->dev->max_fib_size - sizeof(struct aac_fibhdr)));
> diff --git a/drivers/scsi/aacraid/aacraid.h b/drivers/scsi/aacraid/aacraid.h
> index d1fc1ce2e36d..87015dd2abd9 100644
> --- a/drivers/scsi/aacraid/aacraid.h
> +++ b/drivers/scsi/aacraid/aacraid.h
> @@ -527,7 +527,7 @@ struct user_sgmap64 {
>
> struct sgmapraw {
> __le32 count;
> - struct sgentryraw sg[1];
> + struct sgentryraw sg[];
> };
>
> struct user_sgmapraw {
> --
> 2.34.1
>

--
Kees Cook