Description

In the Linux kernel, the following vulnerability has been resolved:

USB: core: Fix race by not overwriting udev->descriptor in hub_port_init()

Syzbot reported an out-of-bounds read in sysfs.c:read_descriptors():

BUG: KASAN: slab-out-of-bounds in read_descriptors+0x263/0x280 drivers/usb/core/sysfs.c:883
Read of size 8 at addr ffff88801e78b8c8 by task udevd/5011

CPU: 0 PID: 5011 Comm: udevd Not tainted 6.4.0-rc6-syzkaller-00195-g40f71e7cd3c6 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023
Call Trace:

__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106
print_address_description.constprop.0+0x2c/0x3c0 mm/kasan/report.c:351
print_report mm/kasan/report.c:462 [inline]
kasan_report+0x11c/0x130 mm/kasan/report.c:572
read_descriptors+0x263/0x280 drivers/usb/core/sysfs.c:883
...
Allocated by task 758:
...
__do_kmalloc_node mm/slab_common.c:966 [inline]
__kmalloc+0x5e/0x190 mm/slab_common.c:979
kmalloc include/linux/slab.h:563 [inline]
kzalloc include/linux/slab.h:680 [inline]
usb_get_configuration+0x1f7/0x5170 drivers/usb/core/config.c:887
usb_enumerate_device drivers/usb/core/hub.c:2407 [inline]
usb_new_device+0x12b0/0x19d0 drivers/usb/core/hub.c:2545

As analyzed by Khazhy Kumykov, the cause of this bug is a race between
read_descriptors() and hub_port_init(): The first routine uses a field
in udev->descriptor, not expecting it to change, while the second
overwrites it.

Prior to c...

Classification

CVE ID: CVE-2023-52886

Affected Products

Vendor: Linux

Product: Linux

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.05% (probability of being exploited)

EPSS Percentile: 20.68% (scored less or equal to compared to others)

EPSS Date: 2025-02-03 (when was this score calculated)

References

https://git.kernel.org/stable/c/9d241c5d9a9b7ad95c90c6520272fe404d5ac88f
https://git.kernel.org/stable/c/7fe9d87996062f5eb0ca476ad0257f79bf43aaf5
https://git.kernel.org/stable/c/8186596a663506b1124bede9fde6f243ef9f37ee
https://git.kernel.org/stable/c/b4a074b1fb222164ed7d5c0b8c922dc4a0840848
https://git.kernel.org/stable/c/b9fbfb349eacc0820f91c797d7f0a3ac7a4935b5
https://git.kernel.org/stable/c/ff33299ec8bb80cdcc073ad9c506bd79bb2ed20b

Timeline