A security advisory (TALOS-2019-0857/CVE-2019-5068) found that
creating shared memory regions with permission mode 0777 could allow
any user to access that memory. Several Mesa drivers use shared-
memory XImages to implement back buffers for improved performance.
This path changes the shmget() calls to use 0600 (user r/w).
Tested with legacy Xlib driver and llvmpipe.
Cc: mesa-stable@lists.freedesktop.org
Reviewed-by: Kristian H. Kristensen <hoegsberg@google.com>
(cherry picked from commit
02c3dad0f3b4d26e0faa5cc51d06bc50d693dcdc)
{
char *addr;
- dri_sw_dt->shmid = shmget(IPC_PRIVATE, size, IPC_CREAT|0777);
+ /* 0600 = user read+write */
+ dri_sw_dt->shmid = shmget(IPC_PRIVATE, size, IPC_CREAT | 0600);
if (dri_sw_dt->shmid < 0)
return NULL;
shminfo->shmid = -1;
shminfo->shmaddr = (char *) -1;
- shminfo->shmid = shmget(IPC_PRIVATE, size, IPC_CREAT|0777);
+ /* 0600 = user read+write */
+ shminfo->shmid = shmget(IPC_PRIVATE, size, IPC_CREAT | 0600);
if (shminfo->shmid < 0) {
return NULL;
}
return GL_FALSE;
}
+ /* 0600 = user read+write */
b->shminfo.shmid = shmget(IPC_PRIVATE, b->backxrb->ximage->bytes_per_line
- * b->backxrb->ximage->height, IPC_CREAT|0777);
+ * b->backxrb->ximage->height, IPC_CREAT | 0600);
if (b->shminfo.shmid < 0) {
_mesa_warning(NULL, "shmget failed while allocating back buffer.\n");
XDestroyImage(b->backxrb->ximage);