ghsa-697g-g69g-85cq
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
usb: gadget: Fix use-after-free bug by not setting udc->dev.driver
The syzbot fuzzer found a use-after-free bug:
BUG: KASAN: use-after-free in dev_uevent+0x712/0x780 drivers/base/core.c:2320 Read of size 8 at addr ffff88802b934098 by task udevd/3689
CPU: 2 PID: 3689 Comm: udevd Not tainted 5.17.0-rc4-syzkaller-00229-g4f12b742eb2b #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014
Call Trace:
Although the bug manifested in the driver core, the real cause was a race with the gadget core. dev_uevent() does:
if (dev->driver)
add_uevent_var(env, "DRIVER=%s", dev->driver->name);
and between the test and the dereference of dev->driver, the gadget core sets dev->driver to NULL.
The race wouldn't occur if the gadget core registered its devices on a real bus, using the standard synchronization techniques of the driver core. However, it's not necessary to make such a large change in order to fix this bug; all we need to do is make sure that udc->dev.driver is always NULL.
In fact, there is no reason for udc->dev.driver ever to be set to anything, let alone to the value it currently gets: the address of the gadget's driver. After all, a gadget driver only knows how to manage a gadget, not how to manage a UDC.
This patch simply removes the statements in the gadget core that touch udc->dev.driver.
{
"affected": [],
"aliases": [
"CVE-2022-48838"
],
"database_specific": {
"cwe_ids": [
"CWE-416"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-07-16T13:15:11Z",
"severity": "MODERATE"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nusb: gadget: Fix use-after-free bug by not setting udc-\u003edev.driver\n\nThe syzbot fuzzer found a use-after-free bug:\n\nBUG: KASAN: use-after-free in dev_uevent+0x712/0x780 drivers/base/core.c:2320\nRead of size 8 at addr ffff88802b934098 by task udevd/3689\n\nCPU: 2 PID: 3689 Comm: udevd Not tainted 5.17.0-rc4-syzkaller-00229-g4f12b742eb2b #0\nHardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014\nCall Trace:\n \u003cTASK\u003e\n __dump_stack lib/dump_stack.c:88 [inline]\n dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106\n print_address_description.constprop.0.cold+0x8d/0x303 mm/kasan/report.c:255\n __kasan_report mm/kasan/report.c:442 [inline]\n kasan_report.cold+0x83/0xdf mm/kasan/report.c:459\n dev_uevent+0x712/0x780 drivers/base/core.c:2320\n uevent_show+0x1b8/0x380 drivers/base/core.c:2391\n dev_attr_show+0x4b/0x90 drivers/base/core.c:2094\n\nAlthough the bug manifested in the driver core, the real cause was a\nrace with the gadget core. dev_uevent() does:\n\n\tif (dev-\u003edriver)\n\t\tadd_uevent_var(env, \"DRIVER=%s\", dev-\u003edriver-\u003ename);\n\nand between the test and the dereference of dev-\u003edriver, the gadget\ncore sets dev-\u003edriver to NULL.\n\nThe race wouldn\u0027t occur if the gadget core registered its devices on\na real bus, using the standard synchronization techniques of the\ndriver core. However, it\u0027s not necessary to make such a large change\nin order to fix this bug; all we need to do is make sure that\nudc-\u003edev.driver is always NULL.\n\nIn fact, there is no reason for udc-\u003edev.driver ever to be set to\nanything, let alone to the value it currently gets: the address of the\ngadget\u0027s driver. After all, a gadget driver only knows how to manage\na gadget, not how to manage a UDC.\n\nThis patch simply removes the statements in the gadget core that touch\nudc-\u003edev.driver.",
"id": "GHSA-697g-g69g-85cq",
"modified": "2024-07-24T21:31:30Z",
"published": "2024-07-16T15:30:47Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2022-48838"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/00bdd9bf1ac6d401ad926d3d8df41b9f1399f646"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/16b1941eac2bd499f065a6739a40ce0011a3d740"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/2015c23610cd0efadaeca4d3a8d1dae9a45aa35a"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/2282a6eb6d4e118e294e43dcc421e0e0fe4040b5"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/27d64436984fb8835a8b7e95993193cc478b162e"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/4325124dde6726267813c736fee61226f1d38f0b"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/609a7119bffe3ddd7c93f2fa65be8917e02a0b7e"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/e2d3a7009e505e120805f449c832942660f3f7f3"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
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