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authorBrian Paul <brianp@vmware.com>2019-10-09 12:05:16 -0600
committerBrian Paul <brianp@vmware.com>2019-11-18 12:28:59 -0700
commit02c3dad0f3b4d26e0faa5cc51d06bc50d693dcdc (patch)
tree701aeb05da830be270d1ff8a663c1dd8c991a871
parentfdaf8144a8bf65afa7dc66b8d827da38e27a850a (diff)
Call shmget() with permission 0600 instead of 0777
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>
-rw-r--r--src/gallium/winsys/sw/dri/dri_sw_winsys.c3
-rw-r--r--src/gallium/winsys/sw/xlib/xlib_sw_winsys.c3
-rw-r--r--src/mesa/drivers/x11/xm_buffer.c3
3 files changed, 6 insertions, 3 deletions
diff --git a/src/gallium/winsys/sw/dri/dri_sw_winsys.c b/src/gallium/winsys/sw/dri/dri_sw_winsys.c
index cbccf4d01df..6173147a1ff 100644
--- a/src/gallium/winsys/sw/dri/dri_sw_winsys.c
+++ b/src/gallium/winsys/sw/dri/dri_sw_winsys.c
@@ -92,7 +92,8 @@ alloc_shm(struct dri_sw_displaytarget *dri_sw_dt, unsigned size)
{
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;
diff --git a/src/gallium/winsys/sw/xlib/xlib_sw_winsys.c b/src/gallium/winsys/sw/xlib/xlib_sw_winsys.c
index be28fae3df2..8e97f0a24af 100644
--- a/src/gallium/winsys/sw/xlib/xlib_sw_winsys.c
+++ b/src/gallium/winsys/sw/xlib/xlib_sw_winsys.c
@@ -126,7 +126,8 @@ alloc_shm(struct xlib_displaytarget *buf, unsigned size)
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;
}
diff --git a/src/mesa/drivers/x11/xm_buffer.c b/src/mesa/drivers/x11/xm_buffer.c
index d945d8af556..0da08a6e64d 100644
--- a/src/mesa/drivers/x11/xm_buffer.c
+++ b/src/mesa/drivers/x11/xm_buffer.c
@@ -89,8 +89,9 @@ alloc_back_shm_ximage(XMesaBuffer b, GLuint width, GLuint height)
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);