1 files changed, 58 insertions, 0 deletions
diff --git a/main/libusb/f6d2cb561402c3b6d3627c0eb89e009b503d9067.patch b/main/libusb/f6d2cb561402c3b6d3627c0eb89e009b503d9067.patch
new file mode 100644
index 00000000000..a38aec15be2
--- /dev/null
+++ b/main/libusb/f6d2cb561402c3b6d3627c0eb89e009b503d9067.patch
@@ -0,0 +1,58 @@
+From f6d2cb561402c3b6d3627c0eb89e009b503d9067 Mon Sep 17 00:00:00 2001
+From: Chris Dickens <christopher.a.dickens@gmail.com>
+Date: Sun, 13 Dec 2020 15:49:19 -0800
+Subject: [PATCH] linux_usbfs: Fix parsing of descriptors for
+ multi-configuration devices
+
+Commit e2be556bd2 ("linux_usbfs: Parse config descriptors during device
+initialization") introduced a regression for devices with multiple
+configurations. The logic that verifies the reported length of the
+configuration descriptors failed to count the length of the
+configuration descriptor itself and would truncate the actual length by
+9 bytes, leading to a parsing error for subsequent descriptors.
+
+Closes #825
+
+Signed-off-by: Chris Dickens <christopher.a.dickens@gmail.com>
+---
+ libusb/os/linux_usbfs.c | 12 ++++++++----
+ libusb/version_nano.h   |  2 +-
+ 2 files changed, 9 insertions(+), 5 deletions(-)
+
+diff --git a/libusb/os/linux_usbfs.c b/libusb/os/linux_usbfs.c
+index fb2ed53a..4d2dc8d6 100644
+--- a/libusb/os/linux_usbfs.c
++++ b/libusb/os/linux_usbfs.c
+@@ -641,7 +641,12 @@ static int seek_to_next_config(struct libusb_context *ctx,
+ 	uint8_t *buffer, size_t len)
+ {
+ 	struct usbi_descriptor_header *header;
+-	int offset = 0;
++	int offset;
++
++	/* Start seeking past the config descriptor */
++	offset = LIBUSB_DT_CONFIG_SIZE;
++	buffer += LIBUSB_DT_CONFIG_SIZE;
++	len -= LIBUSB_DT_CONFIG_SIZE;
+ 
+ 	while (len > 0) {
+ 		if (len < 2) {
+@@ -718,7 +723,7 @@ static int parse_config_descriptors(struct libusb_device *dev)
+ 		}
+ 
+ 		if (priv->sysfs_dir) {
+-			 /*
++			/*
+ 			 * In sysfs wTotalLength is ignored, instead the kernel returns a
+ 			 * config descriptor with verified bLength fields, with descriptors
+ 			 * with an invalid bLength removed.
+@@ -727,8 +732,7 @@ static int parse_config_descriptors(struct libusb_device *dev)
+ 			int offset;
+ 
+ 			if (num_configs > 1 && idx < num_configs - 1) {
+-				offset = seek_to_next_config(ctx, buffer + LIBUSB_DT_CONFIG_SIZE,
+-							     remaining - LIBUSB_DT_CONFIG_SIZE);
++				offset = seek_to_next_config(ctx, buffer, remaining);
+ 				if (offset < 0)
+ 					return offset;
+ 				sysfs_config_len = (uint16_t)offset;