Messages in this thread | | | Subject | Re: [PATCH 1/1] hisi_sas: Fix possible buffer overflows in prep_ssp_v3_hw | From | John Garry <> | Date | Tue, 8 Dec 2020 18:10:37 +0000 |
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On 08/12/2020 16:40, Xiaohui Zhang wrote: > From: Zhang Xiaohui <ruc_zhangxiaohui@163.com> > > prep_ssp_v3_hw() calls memcpy() without checking the > destination size may trigger a buffer overflower, which a > local user could use to cause denial of service or the > execution of arbitrary code. > Fix it by putting the length check before calling memcpy(). > > Signed-off-by: Zhang Xiaohui <ruc_zhangxiaohui@163.com> > --- > drivers/scsi/hisi_sas/hisi_sas_v3_hw.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c > index 7133ca859..2664c36d3 100644 > --- a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c > +++ b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c > @@ -1267,7 +1267,8 @@ static void prep_ssp_v3_hw(struct hisi_hba *hisi_hba, > memcpy(buf_cmd, &task->ssp_task.LUN, 8); > if (!tmf) { > buf_cmd[9] = ssp_task->task_attr | (ssp_task->task_prio << 3); > - memcpy(buf_cmd + 12, scsi_cmnd->cmnd, scsi_cmnd->cmd_len); > + memcpy(buf_cmd + 12, scsi_cmnd->cmnd, > + min_t(unsigned short, scsi_cmnd->cmd_len, strlen(buf_cmd)-12));
buf_cmd is not a NULL-terminated string, it's actually a pointer to a structure.
And you can see that we set buf_cmd[9] previously (which could set as 0), so how can you possibly rely on a strlen(buf_cmd) - 12 being sane?
Thanks, john
> } else { > buf_cmd[10] = tmf->tmf; > switch (tmf->tmf) { >
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