francis.wang
4c86c082a2
Combine poky (Yocto scarthgap), meta-openembedded (scarthgap), and meta-openwrt into a single repository. Components: - poky/ Yocto core framework (BitBake + OE-Core) - meta-openembedded/ Community layers (meta-oe, meta-python, meta-networking) - meta-openwrt/ OpenWrt customization layer - setup-env.sh One-click build environment setup - README.md Project documentation
89 lines
3.6 KiB
Diff
89 lines
3.6 KiB
Diff
From 0735213e5118d5c9c732b7c891446b35e0d6b8d5 Mon Sep 17 00:00:00 2001
|
|
From: MarkLee131 <kaixuan.li@ntu.edu.sg>
|
|
Date: Sat, 25 Apr 2026 18:33:17 +0800
|
|
Subject: [PATCH] descriptor: Fix two memory-safety bugs in malformed
|
|
config descriptor handling
|
|
|
|
Two issues reachable from a malformed config descriptor returned by an
|
|
attached USB device, both surfaced by the same libFuzzer + ASan run.
|
|
|
|
1) parse_interface() reads bNumEndpoints from the interface descriptor and
|
|
increments usb_interface->num_altsetting before entering the inner loop
|
|
that skips class/vendor specific descriptors ahead of the endpoint
|
|
array. If that loop's bLength > size short-read branch fires, the
|
|
function returns before the endpoint array is allocated, leaving the
|
|
caller with bNumEndpoints > 0 and endpoint == NULL. libusb.h documents
|
|
endpoint as an array sized by bNumEndpoints, and the testlibusb and
|
|
xusb examples both iterate it accordingly, so a NULL deref follows.
|
|
Reset bNumEndpoints to 0 before returning so the invariant holds.
|
|
|
|
2) The first-pass loop in parse_iad_array() compares header.bLength
|
|
against the original size argument instead of the remaining bytes,
|
|
so a single descriptor with bLength == size - 1 lets consumed reach
|
|
size - 1 and the next iteration enters with only one byte of buffer
|
|
left. The buf[1] read on the second line of the loop body lands one
|
|
byte past the malloc allocation that backs the descriptor data. The
|
|
sibling parsers parse_configuration() and parse_interface() in the
|
|
same file already use the remaining-bytes form. Switch the IAD parser
|
|
loop guard and bound check to match.
|
|
|
|
Both code paths are reachable from public APIs (libusb_get_*_config_descriptor
|
|
and libusb_get_*_interface_association_descriptors), with the malformed
|
|
input supplied by the attached device. Minimal reproducers are 20 and
|
|
9 bytes respectively.
|
|
|
|
Fixes #1813
|
|
|
|
CVE: CVE-2026-23679 CVE-2026-47104
|
|
Upstream-Status: Backport [https://github.com/libusb/libusb/commit/bc0886173ea15b8cc9bba2918f58a97a7f185231]
|
|
|
|
Backport Changes:
|
|
- The upstream version_nano.h bump is omitted because this is a security
|
|
backport to libusb 1.0.27, not a version upgrade.
|
|
|
|
Signed-off-by: MarkLee131 <kaixuan.li@ntu.edu.sg>
|
|
(cherry picked from commit bc0886173ea15b8cc9bba2918f58a97a7f185231)
|
|
Signed-off-by: Anil Dongare <adongare@cisco.com>
|
|
---
|
|
libusb/descriptor.c | 10 +++++++---
|
|
1 file changed, 7 insertions(+), 3 deletions(-)
|
|
|
|
diff --git a/libusb/descriptor.c b/libusb/descriptor.c
|
|
index 4862c69..97143bb 100644
|
|
--- a/libusb/descriptor.c
|
|
+++ b/libusb/descriptor.c
|
|
@@ -260,6 +260,10 @@ static int parse_interface(libusb_context *ctx,
|
|
usbi_warn(ctx,
|
|
"short extra intf desc read %d/%u",
|
|
size, header->bLength);
|
|
+ /* Keep the invariant: bNumEndpoints > 0 implies
|
|
+ * endpoint != NULL. The endpoint array isn't
|
|
+ * allocated yet on this early return. */
|
|
+ ifp->bNumEndpoints = 0;
|
|
return parsed;
|
|
}
|
|
|
|
@@ -1226,16 +1230,16 @@ static int parse_iad_array(struct libusb_context *ctx,
|
|
|
|
// First pass: Iterate through desc list, count number of IADs
|
|
iad_array->length = 0;
|
|
- while (consumed < size) {
|
|
+ while (size - consumed >= DESC_HEADER_LENGTH) {
|
|
parse_descriptor(buf, "bb", &header);
|
|
if (header.bLength < 2) {
|
|
usbi_err(ctx, "invalid descriptor bLength %d",
|
|
header.bLength);
|
|
return LIBUSB_ERROR_IO;
|
|
}
|
|
- else if (header.bLength > size) {
|
|
+ else if (header.bLength > size - consumed) {
|
|
usbi_warn(ctx, "short config descriptor read %d/%u",
|
|
- size, header.bLength);
|
|
+ size - consumed, header.bLength);
|
|
return LIBUSB_ERROR_IO;
|
|
}
|
|
if (header.bDescriptorType == LIBUSB_DT_INTERFACE_ASSOCIATION)
|
|
--
|
|
2.43.7
|
|
|