| From bippy-1.2.0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@kernel.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2021-47267: usb: fix various gadget panics on 10gbps cabling |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| usb: fix various gadget panics on 10gbps cabling |
| |
| usb_assign_descriptors() is called with 5 parameters, |
| the last 4 of which are the usb_descriptor_header for: |
| full-speed (USB1.1 - 12Mbps [including USB1.0 low-speed @ 1.5Mbps), |
| high-speed (USB2.0 - 480Mbps), |
| super-speed (USB3.0 - 5Gbps), |
| super-speed-plus (USB3.1 - 10Gbps). |
| |
| The differences between full/high/super-speed descriptors are usually |
| substantial (due to changes in the maximum usb block size from 64 to 512 |
| to 1024 bytes and other differences in the specs), while the difference |
| between 5 and 10Gbps descriptors may be as little as nothing |
| (in many cases the same tuning is simply good enough). |
| |
| However if a gadget driver calls usb_assign_descriptors() with |
| a NULL descriptor for super-speed-plus and is then used on a max 10gbps |
| configuration, the kernel will crash with a null pointer dereference, |
| when a 10gbps capable device port + cable + host port combination shows up. |
| (This wouldn't happen if the gadget max-speed was set to 5gbps, but |
| it of course defaults to the maximum, and there's no real reason to |
| artificially limit it) |
| |
| The fix is to simply use the 5gbps descriptor as the 10gbps descriptor, |
| if a 10gbps descriptor wasn't provided. |
| |
| Obviously this won't fix the problem if the 5gbps descriptor is also |
| NULL, but such cases can't be so trivially solved (and any such gadgets |
| are unlikely to be used with USB3 ports any way). |
| |
| The Linux kernel CVE team has assigned CVE-2021-47267 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 3.8 with commit 10287baec761d33f0a82d84b46e37a44030350d8 and fixed in 4.9.273 with commit fd24be23abf3e94260be0f00bb42c7e91d495f87 |
| Issue introduced in 3.8 with commit 10287baec761d33f0a82d84b46e37a44030350d8 and fixed in 4.14.237 with commit 70cd19cb5bd94bbb5bacfc9c1e4ee0071699a604 |
| Issue introduced in 3.8 with commit 10287baec761d33f0a82d84b46e37a44030350d8 and fixed in 4.19.195 with commit 45f9a2fe737dc0a5df270787f2231aee8985cd59 |
| Issue introduced in 3.8 with commit 10287baec761d33f0a82d84b46e37a44030350d8 and fixed in 5.4.126 with commit 5ef23506695b01d5d56a13a092a97f2478069d75 |
| Issue introduced in 3.8 with commit 10287baec761d33f0a82d84b46e37a44030350d8 and fixed in 5.10.44 with commit b972eff874637402ddc4a7dd11fb22538a0b6d28 |
| Issue introduced in 3.8 with commit 10287baec761d33f0a82d84b46e37a44030350d8 and fixed in 5.12.11 with commit ca6bc277430d90375452b60b047763a090b7673e |
| Issue introduced in 3.8 with commit 10287baec761d33f0a82d84b46e37a44030350d8 and fixed in 5.13 with commit 032e288097a553db5653af552dd8035cd2a0ba96 |
| |
| Please see https://www.kernel.org for a full list of currently supported |
| kernel versions by the kernel community. |
| |
| Unaffected versions might change over time as fixes are backported to |
| older supported kernel versions. The official CVE entry at |
| https://cve.org/CVERecord/?id=CVE-2021-47267 |
| will be updated if fixes are backported, please check that for the most |
| up to date information about this issue. |
| |
| |
| Affected files |
| ============== |
| |
| The file(s) affected by this issue are: |
| drivers/usb/gadget/config.c |
| |
| |
| Mitigation |
| ========== |
| |
| The Linux kernel CVE team recommends that you update to the latest |
| stable kernel version for this, and many other bugfixes. Individual |
| changes are never tested alone, but rather are part of a larger kernel |
| release. Cherry-picking individual commits is not recommended or |
| supported by the Linux kernel community at all. If however, updating to |
| the latest release is impossible, the individual changes to resolve this |
| issue can be found at these commits: |
| https://git.kernel.org/stable/c/fd24be23abf3e94260be0f00bb42c7e91d495f87 |
| https://git.kernel.org/stable/c/70cd19cb5bd94bbb5bacfc9c1e4ee0071699a604 |
| https://git.kernel.org/stable/c/45f9a2fe737dc0a5df270787f2231aee8985cd59 |
| https://git.kernel.org/stable/c/5ef23506695b01d5d56a13a092a97f2478069d75 |
| https://git.kernel.org/stable/c/b972eff874637402ddc4a7dd11fb22538a0b6d28 |
| https://git.kernel.org/stable/c/ca6bc277430d90375452b60b047763a090b7673e |
| https://git.kernel.org/stable/c/032e288097a553db5653af552dd8035cd2a0ba96 |
