selftests/bpf: Reject graph kptr use after RCU unlockgrafted

Add a sleepable verifier test that loads a graph-node local kptr in an
explicit RCU read-side critical section, then passes its node to
bpf_rbtree_remove() after the section ends.

Before the verifier fix, the stale NON_OWN_REF flag makes the node look like
a live borrowed reference and the program is accepted. After the fix, the
pointer is demoted without NON_OWN_REF and the graph kfunc argument is
rejected.

Also exercise a graph kptr loaded while a spin lock provides implicit RCU
protection. The pointer must be invalidated when the lock is released, which
guards the required ordering between non-owning-reference invalidation and
RCU demotion.

Update the existing fault-protected load test state description. The
post-unlock pointer no longer carries NON_OWN_REF, but remains readable
because the load is rewritten to use BPF_PROBE_MEM.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20260904084325.52250-7-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 196 insertions, 0 deletions

diff --git a/drivers/media/common/uvc.c b/drivers/media/common/uvc.c
new file mode 100644
index 000000000..0107cedd0
--- /dev/null
+++ b/drivers/media/common/uvc.c
@@ -0,0 +1,196 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/usb/uvc.h>
+#include <linux/videodev2.h>
+
+/* ------------------------------------------------------------------------
+ * Video formats
+ */
+
+static const struct uvc_format_desc uvc_fmts[] = {
+	{
+		.guid		= UVC_GUID_FORMAT_YUY2,
+		.fcc		= V4L2_PIX_FMT_YUYV,
+	},
+	{
+		.guid		= UVC_GUID_FORMAT_YUY2_ISIGHT,
+		.fcc		= V4L2_PIX_FMT_YUYV,
+	},
+	{
+		.guid		= UVC_GUID_FORMAT_NV12,
+		.fcc		= V4L2_PIX_FMT_NV12,
+	},
+	{
+		.guid		= UVC_GUID_FORMAT_MJPEG,
+		.fcc		= V4L2_PIX_FMT_MJPEG,
+	},
+	{
+		.guid		= UVC_GUID_FORMAT_YV12,
+		.fcc		= V4L2_PIX_FMT_YVU420,
+	},
+	{
+		.guid		= UVC_GUID_FORMAT_I420,
+		.fcc		= V4L2_PIX_FMT_YUV420,
+	},
+	{
+		.guid		= UVC_GUID_FORMAT_M420,
+		.fcc		= V4L2_PIX_FMT_M420,
+	},
+	{
+		.guid		= UVC_GUID_FORMAT_P010,
+		.fcc		= V4L2_PIX_FMT_P010,
+	},
+	{
+		.guid		= UVC_GUID_FORMAT_UYVY,
+		.fcc		= V4L2_PIX_FMT_UYVY,
+	},
+	{
+		.guid		= UVC_GUID_FORMAT_Y800,
+		.fcc		= V4L2_PIX_FMT_GREY,
+	},
+	{
+		.guid		= UVC_GUID_FORMAT_Y8,
+		.fcc		= V4L2_PIX_FMT_GREY,
+	},
+	{
+		.guid		= UVC_GUID_FORMAT_D3DFMT_L8,
+		.fcc		= V4L2_PIX_FMT_GREY,
+	},
+	{
+		.guid		= UVC_GUID_FORMAT_KSMEDIA_L8_IR,
+		.fcc		= V4L2_PIX_FMT_GREY,
+	},
+	{
+		.guid		= UVC_GUID_FORMAT_Y10,
+		.fcc		= V4L2_PIX_FMT_Y10,
+	},
+	{
+		.guid		= UVC_GUID_FORMAT_Y12,
+		.fcc		= V4L2_PIX_FMT_Y12,
+	},
+	{
+		.guid		= UVC_GUID_FORMAT_Y16,
+		.fcc		= V4L2_PIX_FMT_Y16,
+	},
+	{
+		.guid		= UVC_GUID_FORMAT_BY8,
+		.fcc		= V4L2_PIX_FMT_SBGGR8,
+	},
+	{
+		.guid		= UVC_GUID_FORMAT_BA81,
+		.fcc		= V4L2_PIX_FMT_SBGGR8,
+	},
+	{
+		.guid		= UVC_GUID_FORMAT_GBRG,
+		.fcc		= V4L2_PIX_FMT_SGBRG8,
+	},
+	{
+		.guid		= UVC_GUID_FORMAT_GRBG,
+		.fcc		= V4L2_PIX_FMT_SGRBG8,
+	},
+	{
+		.guid		= UVC_GUID_FORMAT_RGGB,
+		.fcc		= V4L2_PIX_FMT_SRGGB8,
+	},
+	{
+		.guid		= UVC_GUID_FORMAT_RGBP,
+		.fcc		= V4L2_PIX_FMT_RGB565,
+	},
+	{
+		.guid		= UVC_GUID_FORMAT_D3DFMT_R5G6B5,
+		.fcc		= V4L2_PIX_FMT_RGB565,
+	},
+	{
+		.guid		= UVC_GUID_FORMAT_BGR3,
+		.fcc		= V4L2_PIX_FMT_BGR24,
+	},
+	{
+		.guid		= UVC_GUID_FORMAT_BGR4,
+		.fcc		= V4L2_PIX_FMT_XBGR32,
+	},
+	{
+		.guid		= UVC_GUID_FORMAT_H264,
+		.fcc		= V4L2_PIX_FMT_H264,
+	},
+	{
+		.guid		= UVC_GUID_FORMAT_H265,
+		.fcc		= V4L2_PIX_FMT_HEVC,
+	},
+	{
+		.guid		= UVC_GUID_FORMAT_Y8I,
+		.fcc		= V4L2_PIX_FMT_Y8I,
+	},
+	{
+		.guid		= UVC_GUID_FORMAT_Y12I,
+		.fcc		= V4L2_PIX_FMT_Y12I,
+	},
+	{
+		.guid		= UVC_GUID_FORMAT_Y16I,
+		.fcc		= V4L2_PIX_FMT_Y16I,
+	},
+	{
+		.guid		= UVC_GUID_FORMAT_Z16,
+		.fcc		= V4L2_PIX_FMT_Z16,
+	},
+	{
+		.guid		= UVC_GUID_FORMAT_RW10,
+		.fcc		= V4L2_PIX_FMT_SRGGB10P,
+	},
+	{
+		.guid		= UVC_GUID_FORMAT_BG16,
+		.fcc		= V4L2_PIX_FMT_SBGGR16,
+	},
+	{
+		.guid		= UVC_GUID_FORMAT_GB16,
+		.fcc		= V4L2_PIX_FMT_SGBRG16,
+	},
+	{
+		.guid		= UVC_GUID_FORMAT_RG16,
+		.fcc		= V4L2_PIX_FMT_SRGGB16,
+	},
+	{
+		.guid		= UVC_GUID_FORMAT_GR16,
+		.fcc		= V4L2_PIX_FMT_SGRBG16,
+	},
+	{
+		.guid		= UVC_GUID_FORMAT_INVZ,
+		.fcc		= V4L2_PIX_FMT_Z16,
+	},
+	{
+		.guid		= UVC_GUID_FORMAT_INVI,
+		.fcc		= V4L2_PIX_FMT_Y10,
+	},
+	{
+		.guid		= UVC_GUID_FORMAT_INZI,
+		.fcc		= V4L2_PIX_FMT_INZI,
+	},
+	{
+		.guid		= UVC_GUID_FORMAT_CNF4,
+		.fcc		= V4L2_PIX_FMT_CNF4,
+	},
+	{
+		.guid		= UVC_GUID_FORMAT_HEVC,
+		.fcc		= V4L2_PIX_FMT_HEVC,
+	},
+};
+
+const struct uvc_format_desc *uvc_format_by_guid(const u8 guid[16])
+{
+	unsigned int len = ARRAY_SIZE(uvc_fmts);
+	unsigned int i;
+
+	for (i = 0; i < len; ++i) {
+		if (memcmp(guid, uvc_fmts[i].guid, 16) == 0)
+			return &uvc_fmts[i];
+	}
+
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(uvc_format_by_guid);
+
+MODULE_DESCRIPTION("USB Video Class common code");
+MODULE_LICENSE("GPL");