| Message ID | 20210209152350.207958-1-eblake@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | scsi: Silence gcc warning | expand |
On 2/9/21 4:23 PM, Eric Blake wrote: > On Fedora 33, gcc 10.2.1 notes that scsi_cdb_length(buf) can set > len==-1, which in turn overflows g_malloc(): > > [5/5] Linking target qemu-system-x86_64 > In function ‘scsi_disk_new_request_dump’, > inlined from ‘scsi_new_request’ at ../hw/scsi/scsi-disk.c:2608:9: > ../hw/scsi/scsi-disk.c:2582:19: warning: argument 1 value ‘18446744073709551612’ exceeds maximum object size 9223372036854775807 [-Walloc-size-larger-than=] > 2582 | line_buffer = g_malloc(len * 5 + 1); > | ^ > > Silence it with a decent assertion, since we only convert a buffer to > bytes when we have a valid cdb length. > > Signed-off-by: Eric Blake <eblake@redhat.com> > --- > hw/scsi/scsi-disk.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/hw/scsi/scsi-disk.c b/hw/scsi/scsi-disk.c > index ed52fcd49ff0..b3311a5657b7 100644 > --- a/hw/scsi/scsi-disk.c > +++ b/hw/scsi/scsi-disk.c > @@ -2579,6 +2579,7 @@ static void scsi_disk_new_request_dump(uint32_t lun, uint32_t tag, uint8_t *buf) > int len = scsi_cdb_length(buf); > char *line_buffer, *p; > > + assert(len > 0 && len <= 16); > line_buffer = g_malloc(len * 5 + 1); > > for (i = 0, p = line_buffer; i < len; i++) { > Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Adding qemu-trivial in cc. On 2/9/21 9:44 AM, Philippe Mathieu-Daudé wrote: > On 2/9/21 4:23 PM, Eric Blake wrote: >> On Fedora 33, gcc 10.2.1 notes that scsi_cdb_length(buf) can set >> len==-1, which in turn overflows g_malloc(): >> >> [5/5] Linking target qemu-system-x86_64 >> In function ‘scsi_disk_new_request_dump’, >> inlined from ‘scsi_new_request’ at ../hw/scsi/scsi-disk.c:2608:9: >> ../hw/scsi/scsi-disk.c:2582:19: warning: argument 1 value ‘18446744073709551612’ exceeds maximum object size 9223372036854775807 [-Walloc-size-larger-than=] >> 2582 | line_buffer = g_malloc(len * 5 + 1); >> | ^ >> >> Silence it with a decent assertion, since we only convert a buffer to >> bytes when we have a valid cdb length. >> >> Signed-off-by: Eric Blake <eblake@redhat.com> >> --- >> hw/scsi/scsi-disk.c | 1 + >> 1 file changed, 1 insertion(+) >> >> diff --git a/hw/scsi/scsi-disk.c b/hw/scsi/scsi-disk.c >> index ed52fcd49ff0..b3311a5657b7 100644 >> --- a/hw/scsi/scsi-disk.c >> +++ b/hw/scsi/scsi-disk.c >> @@ -2579,6 +2579,7 @@ static void scsi_disk_new_request_dump(uint32_t lun, uint32_t tag, uint8_t *buf) >> int len = scsi_cdb_length(buf); >> char *line_buffer, *p; >> >> + assert(len > 0 && len <= 16); >> line_buffer = g_malloc(len * 5 + 1); >> >> for (i = 0, p = line_buffer; i < len; i++) { >> > > Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> >
Le 08/03/2021 à 20:54, Eric Blake a écrit : > Adding qemu-trivial in cc. > > On 2/9/21 9:44 AM, Philippe Mathieu-Daudé wrote: >> On 2/9/21 4:23 PM, Eric Blake wrote: >>> On Fedora 33, gcc 10.2.1 notes that scsi_cdb_length(buf) can set >>> len==-1, which in turn overflows g_malloc(): >>> >>> [5/5] Linking target qemu-system-x86_64 >>> In function ‘scsi_disk_new_request_dump’, >>> inlined from ‘scsi_new_request’ at ../hw/scsi/scsi-disk.c:2608:9: >>> ../hw/scsi/scsi-disk.c:2582:19: warning: argument 1 value ‘18446744073709551612’ exceeds maximum object size 9223372036854775807 [-Walloc-size-larger-than=] >>> 2582 | line_buffer = g_malloc(len * 5 + 1); >>> | ^ >>> >>> Silence it with a decent assertion, since we only convert a buffer to >>> bytes when we have a valid cdb length. >>> >>> Signed-off-by: Eric Blake <eblake@redhat.com> >>> --- >>> hw/scsi/scsi-disk.c | 1 + >>> 1 file changed, 1 insertion(+) >>> >>> diff --git a/hw/scsi/scsi-disk.c b/hw/scsi/scsi-disk.c >>> index ed52fcd49ff0..b3311a5657b7 100644 >>> --- a/hw/scsi/scsi-disk.c >>> +++ b/hw/scsi/scsi-disk.c >>> @@ -2579,6 +2579,7 @@ static void scsi_disk_new_request_dump(uint32_t lun, uint32_t tag, uint8_t *buf) >>> int len = scsi_cdb_length(buf); >>> char *line_buffer, *p; >>> >>> + assert(len > 0 && len <= 16); >>> line_buffer = g_malloc(len * 5 + 1); >>> >>> for (i = 0, p = line_buffer; i < len; i++) { >>> >> >> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> >> > Applied to my trivial-patches branch. Thanks, Laurent
diff --git a/hw/scsi/scsi-disk.c b/hw/scsi/scsi-disk.c index ed52fcd49ff0..b3311a5657b7 100644 --- a/hw/scsi/scsi-disk.c +++ b/hw/scsi/scsi-disk.c @@ -2579,6 +2579,7 @@ static void scsi_disk_new_request_dump(uint32_t lun, uint32_t tag, uint8_t *buf) int len = scsi_cdb_length(buf); char *line_buffer, *p; + assert(len > 0 && len <= 16); line_buffer = g_malloc(len * 5 + 1); for (i = 0, p = line_buffer; i < len; i++) {
On Fedora 33, gcc 10.2.1 notes that scsi_cdb_length(buf) can set len==-1, which in turn overflows g_malloc(): [5/5] Linking target qemu-system-x86_64 In function ‘scsi_disk_new_request_dump’, inlined from ‘scsi_new_request’ at ../hw/scsi/scsi-disk.c:2608:9: ../hw/scsi/scsi-disk.c:2582:19: warning: argument 1 value ‘18446744073709551612’ exceeds maximum object size 9223372036854775807 [-Walloc-size-larger-than=] 2582 | line_buffer = g_malloc(len * 5 + 1); | ^ Silence it with a decent assertion, since we only convert a buffer to bytes when we have a valid cdb length. Signed-off-by: Eric Blake <eblake@redhat.com> --- hw/scsi/scsi-disk.c | 1 + 1 file changed, 1 insertion(+)