From: Alan Stern <stern@rowland.harvard.edu> stable inclusion from stable-v5.10.222 commit d09dd21bb5215d583ca9a1cb1464dbc77a7e88cf category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAGEN0 CVE: CVE-2024-41035 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- commit a368ecde8a5055b627749b09c6218ef793043e47 upstream. Syzbot has identified a bug in usbcore (see the Closes: tag below) caused by our assumption that the reserved bits in an endpoint descriptor's bEndpointAddress field will always be 0. As a result of the bug, the endpoint_is_duplicate() routine in config.c (and possibly other routines as well) may believe that two descriptors are for distinct endpoints, even though they have the same direction and endpoint number. This can lead to confusion, including the bug identified by syzbot (two descriptors with matching endpoint numbers and directions, where one was interrupt and the other was bulk). To fix the bug, we will clear the reserved bits in bEndpointAddress when we parse the descriptor. (Note that both the USB-2.0 and USB-3.1 specs say these bits are "Reserved, reset to zero".) This requires us to make a copy of the descriptor earlier in usb_parse_endpoint() and use the copy instead of the original when checking for duplicates. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Reported-and-tested-by: syzbot+8693a0bb9c10b554272a@syzkaller.appspotmail.com Closes: https://lore.kernel.org/linux-usb/0000000000003d868e061bc0f554@google.com/ Fixes: 0a8fd1346254 ("USB: fix problems with duplicate endpoint addresses") CC: Oliver Neukum <oneukum@suse.com> CC: stable@vger.kernel.org Link: https://lore.kernel.org/r/205a5edc-7fef-4159-b64a-80374b6b101a@rowland.harva... Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Li Huafei <lihuafei1@huawei.com> --- drivers/usb/core/config.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/drivers/usb/core/config.c b/drivers/usb/core/config.c index 2f8a1225b697..1508e0f00dbc 100644 --- a/drivers/usb/core/config.c +++ b/drivers/usb/core/config.c @@ -291,6 +291,20 @@ static int usb_parse_endpoint(struct device *ddev, int cfgno, if (ifp->desc.bNumEndpoints >= num_ep) goto skip_to_next_endpoint_or_interface_descriptor; + /* Save a copy of the descriptor and use it instead of the original */ + endpoint = &ifp->endpoint[ifp->desc.bNumEndpoints]; + memcpy(&endpoint->desc, d, n); + d = &endpoint->desc; + + /* Clear the reserved bits in bEndpointAddress */ + i = d->bEndpointAddress & + (USB_ENDPOINT_DIR_MASK | USB_ENDPOINT_NUMBER_MASK); + if (i != d->bEndpointAddress) { + dev_notice(ddev, "config %d interface %d altsetting %d has an endpoint descriptor with address 0x%X, changing to 0x%X\n", + cfgno, inum, asnum, d->bEndpointAddress, i); + endpoint->desc.bEndpointAddress = i; + } + /* Check for duplicate endpoint addresses */ if (config_endpoint_is_duplicate(config, inum, asnum, d)) { dev_notice(ddev, "config %d interface %d altsetting %d has a duplicate endpoint with address 0x%X, skipping\n", @@ -308,10 +322,8 @@ static int usb_parse_endpoint(struct device *ddev, int cfgno, } } - endpoint = &ifp->endpoint[ifp->desc.bNumEndpoints]; + /* Accept this endpoint */ ++ifp->desc.bNumEndpoints; - - memcpy(&endpoint->desc, d, n); INIT_LIST_HEAD(&endpoint->urb_list); /* -- 2.25.1