| Message ID | 20180910223723.25357-1-labbott@redhat.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | scsi: ibmvscsis: Fix a stringop-overflow warning | expand |
On Mon, Sep 10, 2018 at 3:37 PM, Laura Abbott <labbott@redhat.com> wrote: > There's currently a warning about string overflow with strncat: > > drivers/scsi/ibmvscsi_tgt/ibmvscsi_tgt.c: In function 'ibmvscsis_probe': > drivers/scsi/ibmvscsi_tgt/ibmvscsi_tgt.c:3479:2: error: 'strncat' specified > bound 64 equals destination size [-Werror=stringop-overflow=] > strncat(vscsi->eye, vdev->name, MAX_EYE); > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > Switch to using strlcat which correctly accounts for lengths that > are equal to the destination buffer. > > Signed-off-by: Laura Abbott <labbott@redhat.com> > --- > drivers/scsi/ibmvscsi_tgt/ibmvscsi_tgt.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/scsi/ibmvscsi_tgt/ibmvscsi_tgt.c b/drivers/scsi/ibmvscsi_tgt/ibmvscsi_tgt.c > index fac377320158..53d344d8dc43 100644 > --- a/drivers/scsi/ibmvscsi_tgt/ibmvscsi_tgt.c > +++ b/drivers/scsi/ibmvscsi_tgt/ibmvscsi_tgt.c > @@ -3475,7 +3475,7 @@ static int ibmvscsis_probe(struct vio_dev *vdev, > vscsi->dds.window[REMOTE].liobn); > > strcpy(vscsi->eye, "VSCSI "); > - strncat(vscsi->eye, vdev->name, MAX_EYE); > + strlcat(vscsi->eye, vdev->name, MAX_EYE); Can this just get switched to snprintf() instead? snprintf(vscsi->eye, sizeof(vscsi->eye), "VSCSI%s", vdev->name); > vscsi->dds.unit_id = vdev->unit_address; > strncpy(vscsi->dds.partition_name, partition_name, And does this strncpy need a NUL-termination and/or trailing padding? -Kees
On 9/10/18 6:30 PM, Kees Cook wrote: > On Mon, Sep 10, 2018 at 3:37 PM, Laura Abbott <labbott@redhat.com> wrote: >> There's currently a warning about string overflow with strncat: >> >> drivers/scsi/ibmvscsi_tgt/ibmvscsi_tgt.c: In function 'ibmvscsis_probe': >> drivers/scsi/ibmvscsi_tgt/ibmvscsi_tgt.c:3479:2: error: 'strncat' specified >> bound 64 equals destination size [-Werror=stringop-overflow=] >> strncat(vscsi->eye, vdev->name, MAX_EYE); >> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >> >> Switch to using strlcat which correctly accounts for lengths that >> are equal to the destination buffer. >> >> Signed-off-by: Laura Abbott <labbott@redhat.com> >> --- >> drivers/scsi/ibmvscsi_tgt/ibmvscsi_tgt.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/drivers/scsi/ibmvscsi_tgt/ibmvscsi_tgt.c b/drivers/scsi/ibmvscsi_tgt/ibmvscsi_tgt.c >> index fac377320158..53d344d8dc43 100644 >> --- a/drivers/scsi/ibmvscsi_tgt/ibmvscsi_tgt.c >> +++ b/drivers/scsi/ibmvscsi_tgt/ibmvscsi_tgt.c >> @@ -3475,7 +3475,7 @@ static int ibmvscsis_probe(struct vio_dev *vdev, >> vscsi->dds.window[REMOTE].liobn); >> >> strcpy(vscsi->eye, "VSCSI "); >> - strncat(vscsi->eye, vdev->name, MAX_EYE); >> + strlcat(vscsi->eye, vdev->name, MAX_EYE); > Can this just get switched to snprintf() instead? > > snprintf(vscsi->eye, sizeof(vscsi->eye), "VSCSI%s", vdev->name); Either works for me. > >> vscsi->dds.unit_id = vdev->unit_address; >> strncpy(vscsi->dds.partition_name, partition_name, > And does this strncpy need a NUL-termination and/or trailing padding? > Yes, good catch, it does need NUL-termination. -Bryant
On 09/11/2018 07:34 AM, Bryant G. Ly wrote: > On 9/10/18 6:30 PM, Kees Cook wrote: > >> On Mon, Sep 10, 2018 at 3:37 PM, Laura Abbott <labbott@redhat.com> wrote: >>> There's currently a warning about string overflow with strncat: >>> >>> drivers/scsi/ibmvscsi_tgt/ibmvscsi_tgt.c: In function 'ibmvscsis_probe': >>> drivers/scsi/ibmvscsi_tgt/ibmvscsi_tgt.c:3479:2: error: 'strncat' specified >>> bound 64 equals destination size [-Werror=stringop-overflow=] >>> strncat(vscsi->eye, vdev->name, MAX_EYE); >>> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >>> >>> Switch to using strlcat which correctly accounts for lengths that >>> are equal to the destination buffer. >>> >>> Signed-off-by: Laura Abbott <labbott@redhat.com> >>> --- >>> drivers/scsi/ibmvscsi_tgt/ibmvscsi_tgt.c | 2 +- >>> 1 file changed, 1 insertion(+), 1 deletion(-) >>> >>> diff --git a/drivers/scsi/ibmvscsi_tgt/ibmvscsi_tgt.c b/drivers/scsi/ibmvscsi_tgt/ibmvscsi_tgt.c >>> index fac377320158..53d344d8dc43 100644 >>> --- a/drivers/scsi/ibmvscsi_tgt/ibmvscsi_tgt.c >>> +++ b/drivers/scsi/ibmvscsi_tgt/ibmvscsi_tgt.c >>> @@ -3475,7 +3475,7 @@ static int ibmvscsis_probe(struct vio_dev *vdev, >>> vscsi->dds.window[REMOTE].liobn); >>> >>> strcpy(vscsi->eye, "VSCSI "); >>> - strncat(vscsi->eye, vdev->name, MAX_EYE); >>> + strlcat(vscsi->eye, vdev->name, MAX_EYE); >> Can this just get switched to snprintf() instead? >> >> snprintf(vscsi->eye, sizeof(vscsi->eye), "VSCSI%s", vdev->name); > > Either works for me. > I'll switch to the snprintf since that's cleaner. >> >>> vscsi->dds.unit_id = vdev->unit_address; >>> strncpy(vscsi->dds.partition_name, partition_name, >> And does this strncpy need a NUL-termination and/or trailing padding? >> > Yes, good catch, it does need NUL-termination. > I can send that cleanup in a second patch. > -Bryant > >
diff --git a/drivers/scsi/ibmvscsi_tgt/ibmvscsi_tgt.c b/drivers/scsi/ibmvscsi_tgt/ibmvscsi_tgt.c index fac377320158..53d344d8dc43 100644 --- a/drivers/scsi/ibmvscsi_tgt/ibmvscsi_tgt.c +++ b/drivers/scsi/ibmvscsi_tgt/ibmvscsi_tgt.c @@ -3475,7 +3475,7 @@ static int ibmvscsis_probe(struct vio_dev *vdev, vscsi->dds.window[REMOTE].liobn); strcpy(vscsi->eye, "VSCSI "); - strncat(vscsi->eye, vdev->name, MAX_EYE); + strlcat(vscsi->eye, vdev->name, MAX_EYE); vscsi->dds.unit_id = vdev->unit_address; strncpy(vscsi->dds.partition_name, partition_name,
There's currently a warning about string overflow with strncat: drivers/scsi/ibmvscsi_tgt/ibmvscsi_tgt.c: In function 'ibmvscsis_probe': drivers/scsi/ibmvscsi_tgt/ibmvscsi_tgt.c:3479:2: error: 'strncat' specified bound 64 equals destination size [-Werror=stringop-overflow=] strncat(vscsi->eye, vdev->name, MAX_EYE); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Switch to using strlcat which correctly accounts for lengths that are equal to the destination buffer. Signed-off-by: Laura Abbott <labbott@redhat.com> --- drivers/scsi/ibmvscsi_tgt/ibmvscsi_tgt.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)