lkml.org 
[lkml]   [2022]   [Sep]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] cxl/pmem: Use size_add() against integer overflow
On Tue, Sep 27, 2022 at 12:02:47AM -0700, Yu Zhe wrote:
> "struct_size() + n" may cause a integer overflow,
> use size_add() to handle it.
>
> Signed-off-by: Yu Zhe <yuzhe@nfschina.com>
> ---
> drivers/cxl/pmem.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/cxl/pmem.c b/drivers/cxl/pmem.c
> index 7dc0a2fa1a6b..8c08aa009a56 100644
> --- a/drivers/cxl/pmem.c
> +++ b/drivers/cxl/pmem.c
> @@ -148,7 +148,7 @@ static int cxl_pmem_set_config_data(struct cxl_dev_state *cxlds,
> return -EINVAL;
>
> /* 4-byte status follows the input data in the payload */
> - if (struct_size(cmd, in_buf, cmd->in_length) + 4 > buf_len)
> + if (size_add(struct_size(cmd, in_buf, cmd->in_length), 4) > buf_len)

I don't see any benefit here.

struct_size() calls __ab_c_size() which already calls check_add_overflow()? So
why wrap that in another check?

Were you able to get this to fail with some user input?

Ira

> return -EINVAL;
>
> set_lsa =
> --
> 2.11.0
>

\
 
 \ /
  Last update: 2022-09-27 18:23    [W:0.055 / U:1.308 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site