From: Greg Kroah-Hartman
mainline inclusion
form mainline-v5.16-rc6
commit f08adf5add9a071160c68bb2a61d697f39ab0758
issue: #I4RVJ4
CVE: CVE-2021-39685
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
Signed-off-by: Yu Changchun
--------------------------------
Szymon rightly pointed out that the previous check for the endpoint
direction in bRequestType was not looking at only the bit involved, but
rather the whole value. Normally this is ok, but for some request
types, bits other than bit 8 could be set and the check for the endpoint
length could not stall correctly.
Fix that up by only checking the single bit.
Fixes: 153a2d7e3350 ("USB: gadget: detect too-big endpoint 0 requests")
Cc: Felipe Balbi
Reported-by: Szymon Heidrich
Link: https://lore.kernel.org/r/20211214184621.385828-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman
Signed-off-by: Chen Jun
Signed-off-by: Zheng Zengkai
Signed-off-by: Yu Changchun
---
drivers/usb/gadget/composite.c | 6 +++---
drivers/usb/gadget/legacy/dbgp.c | 6 +++---
drivers/usb/gadget/legacy/inode.c | 6 +++---
3 files changed, 9 insertions(+), 9 deletions(-)
diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
index 426132988512..8bec0cbf844e 100644
--- a/drivers/usb/gadget/composite.c
+++ b/drivers/usb/gadget/composite.c
@@ -1649,14 +1649,14 @@ composite_setup(struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
u8 endp;
if (w_length > USB_COMP_EP0_BUFSIZ) {
- if (ctrl->bRequestType == USB_DIR_OUT) {
- goto done;
- } else {
+ if (ctrl->bRequestType & USB_DIR_IN) {
/* Cast away the const, we are going to overwrite on purpose. */
__le16 *temp = (__le16 *)&ctrl->wLength;
*temp = cpu_to_le16(USB_COMP_EP0_BUFSIZ);
w_length = USB_COMP_EP0_BUFSIZ;
+ } else {
+ goto done;
}
}
diff --git a/drivers/usb/gadget/legacy/dbgp.c b/drivers/usb/gadget/legacy/dbgp.c
index e567afcb2794..ffe58d44b2cb 100644
--- a/drivers/usb/gadget/legacy/dbgp.c
+++ b/drivers/usb/gadget/legacy/dbgp.c
@@ -346,14 +346,14 @@ static int dbgp_setup(struct usb_gadget *gadget,
u16 len = 0;
if (length > DBGP_REQ_LEN) {
- if (ctrl->bRequestType == USB_DIR_OUT) {
- return err;
- } else {
+ if (ctrl->bRequestType & USB_DIR_IN) {
/* Cast away the const, we are going to overwrite on purpose. */
__le16 *temp = (__le16 *)&ctrl->wLength;
*temp = cpu_to_le16(DBGP_REQ_LEN);
length = DBGP_REQ_LEN;
+ } else {
+ return err;
}
}
diff --git a/drivers/usb/gadget/legacy/inode.c b/drivers/usb/gadget/legacy/inode.c
index 04b9c4f5f129..217d2b66fa51 100644
--- a/drivers/usb/gadget/legacy/inode.c
+++ b/drivers/usb/gadget/legacy/inode.c
@@ -1336,14 +1336,14 @@ gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
u16 w_length = le16_to_cpu(ctrl->wLength);
if (w_length > RBUF_SIZE) {
- if (ctrl->bRequestType == USB_DIR_OUT) {
- return value;
- } else {
+ if (ctrl->bRequestType & USB_DIR_IN) {
/* Cast away the const, we are going to overwrite on purpose. */
__le16 *temp = (__le16 *)&ctrl->wLength;
*temp = cpu_to_le16(RBUF_SIZE);
w_length = RBUF_SIZE;
+ } else {
+ return value;
}
}
--
2.25.1
