drm/radeon: Avoid NULL pointer dereference from atom_index_iio() allocation failure
Smatch anlysis:
drivers/gpu/drm/radeon/atom.c:1242 atom_index_iio() error: potential null
dereference 'ctx->iio'. (kzalloc returns null)
Also cleaned up some checks before calls to kfree(). kfree(NULL) is OK.
Cc: David Airlie <airlied@linux.ie>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: "Michel Dänzer" <michel.daenzer@amd.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
diff --git a/drivers/gpu/drm/radeon/atom.c b/drivers/gpu/drm/radeon/atom.c
index 5ce9bf5..46a9c37 100644
--- a/drivers/gpu/drm/radeon/atom.c
+++ b/drivers/gpu/drm/radeon/atom.c
@@ -1238,6 +1238,8 @@
static void atom_index_iio(struct atom_context *ctx, int base)
{
ctx->iio = kzalloc(2 * 256, GFP_KERNEL);
+ if (!ctx->iio)
+ return;
while (CU8(base) == ATOM_IIO_START) {
ctx->iio[CU8(base + 1)] = base + 2;
base += 2;
@@ -1287,6 +1289,10 @@
ctx->cmd_table = CU16(base + ATOM_ROM_CMD_PTR);
ctx->data_table = CU16(base + ATOM_ROM_DATA_PTR);
atom_index_iio(ctx, CU16(ctx->data_table + ATOM_DATA_IIO_PTR) + 4);
+ if (!ctx->iio) {
+ atom_destroy(ctx);
+ return NULL;
+ }
str = CSTR(CU16(base + ATOM_ROM_MSG_PTR));
while (*str && ((*str == '\n') || (*str == '\r')))
@@ -1335,8 +1341,7 @@
void atom_destroy(struct atom_context *ctx)
{
- if (ctx->iio)
- kfree(ctx->iio);
+ kfree(ctx->iio);
kfree(ctx);
}