{"id":"CVE-2023-52886","summary":"USB: core: Fix race by not overwriting udev-\u003edescriptor in hub_port_init()","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nUSB: core: Fix race by not overwriting udev-\u003edescriptor 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 \u003cTASK\u003e\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-\u003edescriptor, 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-\u003edescriptor 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.","modified":"2026-03-20T12:32:51.900531Z","published":"2024-07-16T09:40:58.495Z","related":["SUSE-SU-2024:2894-1","SUSE-SU-2024:2902-1","SUSE-SU-2024:2929-1","SUSE-SU-2024:2939-1","SUSE-SU-2024:2947-1","SUSE-SU-2024:3194-1","SUSE-SU-2024:3195-1","SUSE-SU-2024:3383-1","SUSE-SU-2025:20044-1","SUSE-SU-2025:20047-1"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/52xxx/CVE-2023-52886.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/7fe9d87996062f5eb0ca476ad0257f79bf43aaf5"},{"type":"WEB","url":"https://git.kernel.org/stable/c/8186596a663506b1124bede9fde6f243ef9f37ee"},{"type":"WEB","url":"https://git.kernel.org/stable/c/9d241c5d9a9b7ad95c90c6520272fe404d5ac88f"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b4a074b1fb222164ed7d5c0b8c922dc4a0840848"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b9fbfb349eacc0820f91c797d7f0a3ac7a4935b5"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ff33299ec8bb80cdcc073ad9c506bd79bb2ed20b"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/52xxx/CVE-2023-52886.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-52886"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"218925bfd5d1436e337c4f961e9c149fbe32de6d"},{"fixed":"9d241c5d9a9b7ad95c90c6520272fe404d5ac88f"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"77358093331e9769855140bf94a3f00ecdcf4bb1"},{"fixed":"7fe9d87996062f5eb0ca476ad0257f79bf43aaf5"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"c87fb861ec185fdc578b4fdc6a05920b6a843840"},{"fixed":"8186596a663506b1124bede9fde6f243ef9f37ee"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"45bf39f8df7f05efb83b302c65ae3b9bc92b7065"},{"fixed":"b4a074b1fb222164ed7d5c0b8c922dc4a0840848"},{"fixed":"b9fbfb349eacc0820f91c797d7f0a3ac7a4935b5"},{"fixed":"ff33299ec8bb80cdcc073ad9c506bd79bb2ed20b"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"0"},{"last_affected":"6badaf880edf51a2da7a439699676394dfdef3e5"},{"last_affected":"5f35b5d3bd6914c68f743741443dfd3a64b0e455"},{"last_affected":"a1e89c8b29d003a20ed2dae6bdae1598d1f23e42"},{"last_affected":"1bcb238c54a9c6dc4bded06b06ba7458a5eefa87"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2023-52886.json"}}],"schema_version":"1.7.5"}