[PATCH net-next v2 2/7] net: mctp: usblib: Add test for splits inside headers
From: James Lee <hidden>
Date: 2026-09-03 02:42:47
Also in:
linux-hardening, lkml
Subsystem:
management component transport protocol (mctp), networking drivers, the rest · Maintainers:
Jeremy Kerr, Matt Johnston, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
Add test covering every possible split of a packet's headers between transfers and remove parameterized tests that are now covered. Signed-off-by: James Lee <redacted> --- v2: - Replace direct calls to mctp_usblib_rx_complete() - Fix sk_buff leak --- drivers/net/mctp/mctp-usblib-test.c | 71 +++++++++++++++++++++++++++++++++---- 1 file changed, 65 insertions(+), 6 deletions(-)
diff --git a/drivers/net/mctp/mctp-usblib-test.c b/drivers/net/mctp/mctp-usblib-test.c
index 4c27307900fb6116572bc9d89f3def6f06c30397..a2ca79f61910af129af956a6f38ad69d5dae8c10 100644
--- a/drivers/net/mctp/mctp-usblib-test.c
+++ b/drivers/net/mctp/mctp-usblib-test.c@@ -14,6 +14,8 @@ #include <net/mctpdevice.h> #include <linux/usb/mctp-usb.h> +#define HDR_LEN sizeof(struct mctp_usb_hdr) + struct mctp_usblib_test_dev { struct net_device *ndev; struct mctp_dev *mdev;
@@ -378,12 +380,6 @@ static const struct mctp_usblib_test_pkt_span mctp_usblib_test_pkt_spans[] = { { "1p1x-complete", 1, { 8 }, 1, { 8 } }, /* Two small packets combined within one transfer */ { "2p1x-combined", 2, { 8, 8 }, 1, { 16 } }, - /* A packet split over two transfers, at the MCTP payload */ - { "1p2x-split-payload", 1, { 16 }, 2, { 8, 8 } }, - /* A packet split over two transfers, at the USB transport header */ - { "1p2x-split-usbhdr", 1, { 16 }, 2, { 2, 14 } }, - /* A packet split over two transfers, at the MCTP header */ - { "1p2x-split-mctphdr", 1, { 16 }, 2, { 6, 10 } }, /* Single packet split over 3 transfers, middle entirely continuation */ { "1p3x-split", 1, { 12 }, 3, { 4, 4, 4 } }, /* A packet split over 5 transfers, splitting on and between each header. */
@@ -403,10 +399,73 @@ static const struct mctp_usblib_test_pkt_span mctp_usblib_test_pkt_spans[] = { KUNIT_ARRAY_PARAM(mctp_usblib_test_rx_pkt_span, mctp_usblib_test_pkt_spans, mctp_usblib_test_pkt_span_to_desc); +static void mctp_usblib_test_rx_split_header(struct kunit *test, size_t offset, + struct mctp_usblib_test_dev *dev, + struct mctp_usblib_rx *rx) +{ + struct sk_buff *skb; + size_t buflen, len; + u8 packet[16]; + void *buf; + int rc; + + len = sizeof(packet); + mctp_usblib_test_init_pkt(packet, len, len); + + rc = mctp_usblib_rx_prepare(dev->ndev, rx, &buf, &buflen, GFP_KERNEL); + KUNIT_ASSERT_EQ(test, rc, 0); + KUNIT_ASSERT_GE(test, buflen, len); + + memcpy(buf, packet, offset); + mctp_usblib_test_rx_complete(dev->ndev, rx, offset); + + rc = mctp_usblib_rx_prepare(dev->ndev, rx, &buf, &buflen, + GFP_KERNEL); + KUNIT_ASSERT_EQ(test, rc, 0); + KUNIT_ASSERT_GE(test, buflen, len); + KUNIT_ASSERT_EQ(test, dev->rx_pkts.qlen, 0); + + memcpy(buf, packet + offset, len - offset); + mctp_usblib_test_rx_complete(dev->ndev, rx, len - offset); + KUNIT_EXPECT_EQ(test, dev->rx_pkts.qlen, 1); + + skb = __skb_dequeue(&dev->rx_pkts); + KUNIT_EXPECT_NOT_NULL(test, skb); + if (skb) { + KUNIT_EXPECT_EQ(test, skb->len, len - HDR_LEN); + kfree(skb); + } +} + +static void mctp_usblib_test_rx_header_splits(struct kunit *test) +{ + struct mctp_usblib_test_dev *dev; + struct mctp_usblib_test_ctx *ctx; + struct mctp_usblib_rx *rx; + size_t i; + + ctx = mctp_usblib_test_init(test); + rx = mctp_usblib_test_rx_init(test, true); + dev = ctx->dev; + + /* Unrolling here so stack traces point to the invocation with the + * failing length. + */ + mctp_usblib_test_rx_split_header(test, 1, dev, rx); + mctp_usblib_test_rx_split_header(test, 2, dev, rx); + mctp_usblib_test_rx_split_header(test, 3, dev, rx); + mctp_usblib_test_rx_split_header(test, 4, dev, rx); + mctp_usblib_test_rx_split_header(test, 5, dev, rx); + mctp_usblib_test_rx_split_header(test, 6, dev, rx); + mctp_usblib_test_rx_split_header(test, 7, dev, rx); + mctp_usblib_test_rx_split_header(test, 8, dev, rx); +} + static struct kunit_case mctp_usblib_test_cases[] = { KUNIT_CASE(mctp_usblib_test_rx_single), KUNIT_CASE_PARAM(mctp_usblib_test_rx_pkt_span, mctp_usblib_test_rx_pkt_span_gen_params), + KUNIT_CASE(mctp_usblib_test_rx_header_splits), {} };
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2.47.3