From: Chris Wulff crwulff@gmail.com

mainline inclusion from mainline-v6.11-rc3 commit 973a57891608a98e894db2887f278777f564de18 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAOXZ1 CVE: CVE-2024-44960

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...

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Make sure the descriptor has been set before looking at maxpacket. This fixes a null pointer panic in this case.

This may happen if the gadget doesn't properly set up the endpoint for the current speed, or the gadget descriptors are malformed and the descriptor for the speed/endpoint are not found.

No current gadget driver is known to have this problem, but this may cause a hard-to-find bug during development of new gadgets.

Fixes: 54f83b8c8ea9 ("USB: gadget: Reject endpoints with 0 maxpacket value") Cc: stable@vger.kernel.org Signed-off-by: Chris Wulff crwulff@gmail.com Link: https://lore.kernel.org/r/20240725010419.314430-2-crwulff@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Ye Bin yebin10@huawei.com --- drivers/usb/gadget/udc/core.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c index 7330c1999104..77ee0dbc52c5 100644 --- a/drivers/usb/gadget/udc/core.c +++ b/drivers/usb/gadget/udc/core.c @@ -99,12 +99,10 @@ int usb_ep_enable(struct usb_ep *ep) goto out;

/* UDC drivers can't handle endpoints with maxpacket size 0 */ - if (usb_endpoint_maxp(ep->desc) == 0) { - /* - * We should log an error message here, but we can't call - * dev_err() because there's no way to find the gadget - * given only ep. - */ + if (!ep->desc || usb_endpoint_maxp(ep->desc) == 0) { + WARN_ONCE(1, "%s: ep%d (%s) has %s\n", __func__, ep->address, ep->name, + (!ep->desc) ? "NULL descriptor" : "maxpacket 0"); + ret = -EINVAL; goto out; }