| Message ID | 1528982951-52753-1-git-send-email-jiazhouyang09@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, 14 Jun 2018, Zhouyang Jia wrote: > When kcalloc fails, the lack of error-handling code may > cause unexpected results. > > This patch adds error-handling code after calling kcalloc. > > Signed-off-by: Zhouyang Jia <jiazhouyang09@gmail.com> > --- > v1->v2: > - Remove pr_warn statement. > --- > drivers/usb/storage/alauda.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/usb/storage/alauda.c b/drivers/usb/storage/alauda.c > index 900591d..4e17609 100644 > --- a/drivers/usb/storage/alauda.c > +++ b/drivers/usb/storage/alauda.c > @@ -437,6 +437,9 @@ static int alauda_init_media(struct us_data *us) > + MEDIA_INFO(us).blockshift + MEDIA_INFO(us).pageshift); > MEDIA_INFO(us).pba_to_lba = kcalloc(num_zones, sizeof(u16*), GFP_NOIO); > MEDIA_INFO(us).lba_to_pba = kcalloc(num_zones, sizeof(u16*), GFP_NOIO); > + if ((MEDIA_INFO(us).pba_to_lba == NULL) > + || (MEDIA_INFO(us).lba_to_pba == NULL)) > + return USB_STOR_TRANSPORT_ERROR; > > if (alauda_reset_media(us) != USB_STOR_XFER_GOOD) > return USB_STOR_TRANSPORT_ERROR; > Acked-by: Alan Stern <stern@rowland.harvard.edu> -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, Jun 14, 2018 at 09:29:11PM +0800, Zhouyang Jia wrote: > When kcalloc fails, the lack of error-handling code may > cause unexpected results. > > This patch adds error-handling code after calling kcalloc. > > Signed-off-by: Zhouyang Jia <jiazhouyang09@gmail.com> > Acked-by: Alan Stern <stern@rowland.harvard.edu> > --- > v1->v2: > - Remove pr_warn statement. > --- > drivers/usb/storage/alauda.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/usb/storage/alauda.c b/drivers/usb/storage/alauda.c > index 900591d..4e17609 100644 > --- a/drivers/usb/storage/alauda.c > +++ b/drivers/usb/storage/alauda.c > @@ -437,6 +437,9 @@ static int alauda_init_media(struct us_data *us) > + MEDIA_INFO(us).blockshift + MEDIA_INFO(us).pageshift); > MEDIA_INFO(us).pba_to_lba = kcalloc(num_zones, sizeof(u16*), GFP_NOIO); > MEDIA_INFO(us).lba_to_pba = kcalloc(num_zones, sizeof(u16*), GFP_NOIO); > + if ((MEDIA_INFO(us).pba_to_lba == NULL) > + || (MEDIA_INFO(us).lba_to_pba == NULL)) > + return USB_STOR_TRANSPORT_ERROR; You just leaked memory if only one of these succeeded :( -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, 25 Jun 2018, Greg Kroah-Hartman wrote: > On Thu, Jun 14, 2018 at 09:29:11PM +0800, Zhouyang Jia wrote: > > When kcalloc fails, the lack of error-handling code may > > cause unexpected results. > > > > This patch adds error-handling code after calling kcalloc. > > > > Signed-off-by: Zhouyang Jia <jiazhouyang09@gmail.com> > > Acked-by: Alan Stern <stern@rowland.harvard.edu> > > --- > > v1->v2: > > - Remove pr_warn statement. > > --- > > drivers/usb/storage/alauda.c | 3 +++ > > 1 file changed, 3 insertions(+) > > > > diff --git a/drivers/usb/storage/alauda.c b/drivers/usb/storage/alauda.c > > index 900591d..4e17609 100644 > > --- a/drivers/usb/storage/alauda.c > > +++ b/drivers/usb/storage/alauda.c > > @@ -437,6 +437,9 @@ static int alauda_init_media(struct us_data *us) > > + MEDIA_INFO(us).blockshift + MEDIA_INFO(us).pageshift); > > MEDIA_INFO(us).pba_to_lba = kcalloc(num_zones, sizeof(u16*), GFP_NOIO); > > MEDIA_INFO(us).lba_to_pba = kcalloc(num_zones, sizeof(u16*), GFP_NOIO); > > + if ((MEDIA_INFO(us).pba_to_lba == NULL) > > + || (MEDIA_INFO(us).lba_to_pba == NULL)) > > + return USB_STOR_TRANSPORT_ERROR; > > You just leaked memory if only one of these succeeded :( That's not really true. The memory gets deallocated later on in any case, when alauda_info_destructor() calls alauda_free_maps() if not before. More troubling is the fact that this routine (i.e, alauda_init_media) gets called from only one place, in alauda_check_media, and the caller completely ignores the return value! Furthermore, the caller always returns USB_STOR_TRANSPORT_FAILED. So on the whole, I don't think this patch is going to make any difference to the driver's operation. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, Jun 25, 2018 at 11:22:34AM -0400, Alan Stern wrote: > On Mon, 25 Jun 2018, Greg Kroah-Hartman wrote: > > > On Thu, Jun 14, 2018 at 09:29:11PM +0800, Zhouyang Jia wrote: > > > When kcalloc fails, the lack of error-handling code may > > > cause unexpected results. > > > > > > This patch adds error-handling code after calling kcalloc. > > > > > > Signed-off-by: Zhouyang Jia <jiazhouyang09@gmail.com> > > > Acked-by: Alan Stern <stern@rowland.harvard.edu> > > > --- > > > v1->v2: > > > - Remove pr_warn statement. > > > --- > > > drivers/usb/storage/alauda.c | 3 +++ > > > 1 file changed, 3 insertions(+) > > > > > > diff --git a/drivers/usb/storage/alauda.c b/drivers/usb/storage/alauda.c > > > index 900591d..4e17609 100644 > > > --- a/drivers/usb/storage/alauda.c > > > +++ b/drivers/usb/storage/alauda.c > > > @@ -437,6 +437,9 @@ static int alauda_init_media(struct us_data *us) > > > + MEDIA_INFO(us).blockshift + MEDIA_INFO(us).pageshift); > > > MEDIA_INFO(us).pba_to_lba = kcalloc(num_zones, sizeof(u16*), GFP_NOIO); > > > MEDIA_INFO(us).lba_to_pba = kcalloc(num_zones, sizeof(u16*), GFP_NOIO); > > > + if ((MEDIA_INFO(us).pba_to_lba == NULL) > > > + || (MEDIA_INFO(us).lba_to_pba == NULL)) > > > + return USB_STOR_TRANSPORT_ERROR; > > > > You just leaked memory if only one of these succeeded :( > > That's not really true. The memory gets deallocated later on in any > case, when alauda_info_destructor() calls alauda_free_maps() if not > before. > > More troubling is the fact that this routine (i.e, alauda_init_media) > gets called from only one place, in alauda_check_media, and the caller > completely ignores the return value! Furthermore, the caller always > returns USB_STOR_TRANSPORT_FAILED. > > So on the whole, I don't think this patch is going to make any > difference to the driver's operation. Ok, I'm just going to drop it then. thanks, greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/usb/storage/alauda.c b/drivers/usb/storage/alauda.c index 900591d..4e17609 100644 --- a/drivers/usb/storage/alauda.c +++ b/drivers/usb/storage/alauda.c @@ -437,6 +437,9 @@ static int alauda_init_media(struct us_data *us) + MEDIA_INFO(us).blockshift + MEDIA_INFO(us).pageshift); MEDIA_INFO(us).pba_to_lba = kcalloc(num_zones, sizeof(u16*), GFP_NOIO); MEDIA_INFO(us).lba_to_pba = kcalloc(num_zones, sizeof(u16*), GFP_NOIO); + if ((MEDIA_INFO(us).pba_to_lba == NULL) + || (MEDIA_INFO(us).lba_to_pba == NULL)) + return USB_STOR_TRANSPORT_ERROR; if (alauda_reset_media(us) != USB_STOR_XFER_GOOD) return USB_STOR_TRANSPORT_ERROR;
When kcalloc fails, the lack of error-handling code may cause unexpected results. This patch adds error-handling code after calling kcalloc. Signed-off-by: Zhouyang Jia <jiazhouyang09@gmail.com> --- v1->v2: - Remove pr_warn statement. --- drivers/usb/storage/alauda.c | 3 +++ 1 file changed, 3 insertions(+)