ACK[T]: [CVE-2017-14051][Trusty][Zesty][SRU][PATCH 1/1] scsi: qla2xxx: Fix an integer overflow in sysfs code

[Kleber Souza]

On 01/10/18 10:48, Po-Hsu Lin wrote:
> From: Dan Carpenter <dan.carpenter at oracle.com>
> 
> CVE-2017-14051
> 
> The value of "size" comes from the user.  When we add "start + size" it
> could lead to an integer overflow bug.
> 
> It means we vmalloc() a lot more memory than we had intended.  I believe
> that on 64 bit systems vmalloc() can succeed even if we ask it to
> allocate huge 4GB buffers.  So we would get memory corruption and likely
> a crash when we call ha->isp_ops->write_optrom() and ->read_optrom().
> 
> Only root can trigger this bug.
> 
> Link: https://bugzilla.kernel.org/show_bug.cgi?id=194061
> 
> Cc: <stable at vger.kernel.org>
> Fixes: b7cc176c9eb3 ("[SCSI] qla2xxx: Allow region-based flash-part accesses.")
> Reported-by: shqking <shqking at gmail.com>
> Signed-off-by: Dan Carpenter <dan.carpenter at oracle.com>
> Signed-off-by: Martin K. Petersen <martin.petersen at oracle.com>
> (cherry picked from commit e6f77540c067b48dee10f1e33678415bfcc89017)
> Signed-off-by: Po-Hsu Lin <po-hsu.lin at canonical.com>
> ---
>  drivers/scsi/qla2xxx/qla_attr.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/scsi/qla2xxx/qla_attr.c b/drivers/scsi/qla2xxx/qla_attr.c
> index 5f174b8..08dd6a3 100644
> --- a/drivers/scsi/qla2xxx/qla_attr.c
> +++ b/drivers/scsi/qla2xxx/qla_attr.c
> @@ -303,6 +303,8 @@ qla2x00_sysfs_write_optrom_ctl(struct file *filp, struct kobject *kobj,
>  		return -EINVAL;
>  	if (start > ha->optrom_size)
>  		return -EINVAL;
> +	if (size > ha->optrom_size - start)
> +		size = ha->optrom_size - start;
>  
>  	switch (val) {
>  	case 0:
> @@ -324,8 +326,7 @@ qla2x00_sysfs_write_optrom_ctl(struct file *filp, struct kobject *kobj,
>  			return -EINVAL;
>  
>  		ha->optrom_region_start = start;
> -		ha->optrom_region_size = start + size > ha->optrom_size ?
> -		    ha->optrom_size - start : size;
> +		ha->optrom_region_size = start + size;
>  
>  		ha->optrom_state = QLA_SREADING;
>  		ha->optrom_buffer = vmalloc(ha->optrom_region_size);
> @@ -392,8 +393,7 @@ qla2x00_sysfs_write_optrom_ctl(struct file *filp, struct kobject *kobj,
>  		}
>  
>  		ha->optrom_region_start = start;
> -		ha->optrom_region_size = start + size > ha->optrom_size ?
> -		    ha->optrom_size - start : size;
> +		ha->optrom_region_size = start + size;
>  
>  		ha->optrom_state = QLA_SWRITING;
>  		ha->optrom_buffer = vmalloc(ha->optrom_region_size);
> 

Clean cherry-pick. For trusty:

Acked-by: Kleber Sacilotto de Souza <kleber.souza at canonical.com>


Please note that Zesty has reached EOL and doesn't need this fix.


Thanks,
Kleber