diff mbox series

[2/5] scsi: BusLogic: Avoid unbounded `vsprintf' use

Message ID alpine.DEB.2.21.2104141521190.44318@angie.orcam.me.uk
State Superseded
Headers show
Series Bring the BusLogic host bus adapter driver up to Y2021 | expand

Commit Message

Maciej W. Rozycki April 14, 2021, 10:39 p.m. UTC
Existing `blogic_msg' invocations do not appear to overrun its internal 
buffer of a fixed length of 100, which would cause stack corruption, but 
it's easy to miss with possible further updates and a fix is cheap in 
performance terms, so limit the output produced into the buffer by using 
`vsnprintf' rather than `vsprintf'.

Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
---
 drivers/scsi/BusLogic.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

linux-buslogic-vsnprintf.diff

Comments

Khalid Aziz April 16, 2021, 7:54 p.m. UTC | #1
On 4/14/21 4:39 PM, Maciej W. Rozycki wrote:
> Existing `blogic_msg' invocations do not appear to overrun its internal 

> buffer of a fixed length of 100, which would cause stack corruption, but 

> it's easy to miss with possible further updates and a fix is cheap in 

> performance terms, so limit the output produced into the buffer by using 

> `vsnprintf' rather than `vsprintf'.

> 

> Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>

> ---

>  drivers/scsi/BusLogic.c |    2 +-

>  1 file changed, 1 insertion(+), 1 deletion(-)

> 

> linux-buslogic-vsnprintf.diff

> Index: linux-macro-ide/drivers/scsi/BusLogic.c

> ===================================================================

> --- linux-macro-ide.orig/drivers/scsi/BusLogic.c

> +++ linux-macro-ide/drivers/scsi/BusLogic.c

> @@ -3588,7 +3588,7 @@ static void blogic_msg(enum blogic_msgle

>  	int len = 0;

>  

>  	va_start(args, adapter);

> -	len = vsprintf(buf, fmt, args);

> +	len = vsnprintf(buf, sizeof(buf), fmt, args);

>  	va_end(args);

>  	if (msglevel == BLOGIC_ANNOUNCE_LEVEL) {

>  		static int msglines = 0;

> 


As Maciej explained in other email that snprintf() does null-terminate
the string, I think this change is fine.

Acked-by: Khalid Aziz <khalid@gonehiking.org>
diff mbox series

Patch

Index: linux-macro-ide/drivers/scsi/BusLogic.c
===================================================================
--- linux-macro-ide.orig/drivers/scsi/BusLogic.c
+++ linux-macro-ide/drivers/scsi/BusLogic.c
@@ -3588,7 +3588,7 @@  static void blogic_msg(enum blogic_msgle
 	int len = 0;
 
 	va_start(args, adapter);
-	len = vsprintf(buf, fmt, args);
+	len = vsnprintf(buf, sizeof(buf), fmt, args);
 	va_end(args);
 	if (msglevel == BLOGIC_ANNOUNCE_LEVEL) {
 		static int msglines = 0;