{"cve":"CVE-2023-52886","nvd":{"published":"2024-07-16T10:15:02.493","modified":"2026-06-17T06:43:51.527","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nUSB: core: Fix race by not overwriting udev->descriptor in hub_port_init()\n\nSyzbot reported an out-of-bounds read in sysfs.c:read_descriptors():\n\nBUG: KASAN: slab-out-of-bounds in read_descriptors+0x263/0x280 drivers/usb/core/sysfs.c:883\nRead of size 8 at addr ffff88801e78b8c8 by task udevd/5011\n\nCPU: 0 PID: 5011 Comm: udevd Not tainted 6.4.0-rc6-syzkaller-00195-g40f71e7cd3c6 #0\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023\nCall Trace:\n <TASK>\n __dump_stack lib/dump_stack.c:88 [inline]\n dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106\n print_address_description.constprop.0+0x2c/0x3c0 mm/kasan/report.c:351\n print_report mm/kasan/report.c:462 [inline]\n kasan_report+0x11c/0x130 mm/kasan/report.c:572\n read_descriptors+0x263/0x280 drivers/usb/core/sysfs.c:883\n...\nAllocated by task 758:\n...\n __do_kmalloc_node mm/slab_common.c:966 [inline]\n __kmalloc+0x5e/0x190 mm/slab_common.c:979\n kmalloc include/linux/slab.h:563 [inline]\n kzalloc include/linux/slab.h:680 [inline]\n usb_get_configuration+0x1f7/0x5170 drivers/usb/core/config.c:887\n usb_enumerate_device drivers/usb/core/hub.c:2407 [inline]\n usb_new_device+0x12b0/0x19d0 drivers/usb/core/hub.c:2545\n\nAs analyzed by Khazhy Kumykov, the cause of this bug is a race between\nread_descriptors() and hub_port_init(): The first routine uses a field\nin udev->descriptor, not expecting it to change, while the second\noverwrites it.\n\nPrior to commit 45bf39f8df7f (\"USB: core: Don't hold device lock while\nreading the \"descriptors\" sysfs file\") this race couldn't occur,\nbecause the routines were mutually exclusive thanks to the device\nlocking.  Removing that locking from read_descriptors() exposed it to\nthe race.\n\nThe best way to fix the bug is to keep hub_port_init() from changing\nudev->descriptor once udev has been initialized and registered.\nDrivers expect the descriptors stored in the kernel to be immutable;\nwe should not undermine this expectation.  In fact, this change should\nhave been made long ago.\n\nSo now hub_port_init() will take an additional argument, specifying a\nbuffer in which to store the device descriptor it reads.  (If udev has\nnot yet been initialized, the buffer pointer will be NULL and then\nhub_port_init() will store the device descriptor in udev as before.)\nThis eliminates the data race responsible for the out-of-bounds read.\n\nThe changes to hub_port_init() appear more extensive than they really\nare, because of indentation changes resulting from an attempt to avoid\nwriting to other parts of the usb_device structure after it has been\ninitialized.  Similar changes should be made to the code that reads\nthe BOS descriptor, but that can be handled in a separate patch later\non.  This patch is sufficient to fix the bug found by syzbot.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:P/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H","score":6.4},"cwes":["CWE-125"],"references":["https://git.kernel.org/stable/c/7fe9d87996062f5eb0ca476ad0257f79bf43aaf5","https://git.kernel.org/stable/c/8186596a663506b1124bede9fde6f243ef9f37ee","https://git.kernel.org/stable/c/9d241c5d9a9b7ad95c90c6520272fe404d5ac88f","https://git.kernel.org/stable/c/b4a074b1fb222164ed7d5c0b8c922dc4a0840848","https://git.kernel.org/stable/c/b9fbfb349eacc0820f91c797d7f0a3ac7a4935b5"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:52:42.518321223+00:00"},"epss":{"cve":"CVE-2023-52886","score":0.00328,"percentile":0.26002,"date":"2026-11-01"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}