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:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
print_address_description.constprop.0.cold+0x8d/0x303 mm/kasan/report.c:255
__kasan_report mm/kasan/report.c:442 [inline]
kasan_report.cold+0x83/0xdf mm/kasan/report.c:459
dev_uevent+0x712/0x780 drivers/base/core.c:2320
uevent_show+0x1b8/0x380 drivers/base/core.c:2391
dev_attr_show+0x4b/0x90 drivers/base/core.c:2094
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.
[
{
"product": "Linux",
"vendor": "Linux",
"defaultStatus": "unaffected",
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"programFiles": [
"drivers/usb/gadget/udc/core.c"
],
"versions": [
{
"version": "2ccea03a8f7e",
"lessThan": "4325124dde67",
"status": "affected",
"versionType": "git"
},
{
"version": "2ccea03a8f7e",
"lessThan": "e2d3a7009e50",
"status": "affected",
"versionType": "git"
},
{
"version": "2ccea03a8f7e",
"lessThan": "609a7119bffe",
"status": "affected",
"versionType": "git"
},
{
"version": "2ccea03a8f7e",
"lessThan": "2282a6eb6d4e",
"status": "affected",
"versionType": "git"
},
{
"version": "2ccea03a8f7e",
"lessThan": "00bdd9bf1ac6",
"status": "affected",
"versionType": "git"
},
{
"version": "2ccea03a8f7e",
"lessThan": "2015c23610cd",
"status": "affected",
"versionType": "git"
},
{
"version": "2ccea03a8f7e",
"lessThan": "27d64436984f",
"status": "affected",
"versionType": "git"
},
{
"version": "2ccea03a8f7e",
"lessThan": "16b1941eac2b",
"status": "affected",
"versionType": "git"
}
]
},
{
"product": "Linux",
"vendor": "Linux",
"defaultStatus": "affected",
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"programFiles": [
"drivers/usb/gadget/udc/core.c"
],
"versions": [
{
"version": "3.1",
"status": "affected"
},
{
"version": "0",
"lessThan": "3.1",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "4.9.308",
"lessThanOrEqual": "4.9.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "4.14.273",
"lessThanOrEqual": "4.14.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "4.19.236",
"lessThanOrEqual": "4.19.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "5.4.187",
"lessThanOrEqual": "5.4.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "5.10.108",
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "5.15.31",
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "5.16.17",
"lessThanOrEqual": "5.16.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "5.17",
"lessThanOrEqual": "*",
"status": "unaffected",
"versionType": "original_commit_for_fix"
}
]
}
]
git.kernel.org/stable/c/00bdd9bf1ac6d401ad926d3d8df41b9f1399f646
git.kernel.org/stable/c/16b1941eac2bd499f065a6739a40ce0011a3d740
git.kernel.org/stable/c/2015c23610cd0efadaeca4d3a8d1dae9a45aa35a
git.kernel.org/stable/c/2282a6eb6d4e118e294e43dcc421e0e0fe4040b5
git.kernel.org/stable/c/27d64436984fb8835a8b7e95993193cc478b162e
git.kernel.org/stable/c/4325124dde6726267813c736fee61226f1d38f0b
git.kernel.org/stable/c/609a7119bffe3ddd7c93f2fa65be8917e02a0b7e
git.kernel.org/stable/c/e2d3a7009e505e120805f449c832942660f3f7f3