{"cve":"CVE-2023-53045","nvd":{"published":"2025-05-02T16:15:23.590","modified":"2026-06-17T06:44:11.407","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nusb: gadget: u_audio: don't let userspace block driver unbind\n\nIn the unbind callback for f_uac1 and f_uac2, a call to snd_card_free()\nvia g_audio_cleanup() will disconnect the card and then wait for all\nresources to be released, which happens when the refcount falls to zero.\nSince userspace can keep the refcount incremented by not closing the\nrelevant file descriptor, the call to unbind may block indefinitely.\nThis can cause a deadlock during reboot, as evidenced by the following\nblocked task observed on my machine:\n\n  task:reboot  state:D stack:0   pid:2827  ppid:569    flags:0x0000000c\n  Call trace:\n   __switch_to+0xc8/0x140\n   __schedule+0x2f0/0x7c0\n   schedule+0x60/0xd0\n   schedule_timeout+0x180/0x1d4\n   wait_for_completion+0x78/0x180\n   snd_card_free+0x90/0xa0\n   g_audio_cleanup+0x2c/0x64\n   afunc_unbind+0x28/0x60\n   ...\n   kernel_restart+0x4c/0xac\n   __do_sys_reboot+0xcc/0x1ec\n   __arm64_sys_reboot+0x28/0x30\n   invoke_syscall+0x4c/0x110\n   ...\n\nThe issue can also be observed by opening the card with arecord and\nthen stopping the process through the shell before unbinding:\n\n  # arecord -D hw:UAC2Gadget -f S32_LE -c 2 -r 48000 /dev/null\n  Recording WAVE '/dev/null' : Signed 32 bit Little Endian, Rate 48000 Hz, Stereo\n  ^Z[1]+  Stopped                    arecord -D hw:UAC2Gadget -f S32_LE -c 2 -r 48000 /dev/null\n  # echo gadget.0 > /sys/bus/gadget/drivers/configfs-gadget/unbind\n  (observe that the unbind command never finishes)\n\nFix the problem by using snd_card_free_when_closed() instead, which will\nstill disconnect the card as desired, but defer the task of freeing the\nresources to the core once userspace closes its file descriptor.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-667"],"references":["https://git.kernel.org/stable/c/0eda2004f38d95ef5715d62be884cd344260535b","https://git.kernel.org/stable/c/3256e152b645fc1e788ba44c2d8ced690113e3e6","https://git.kernel.org/stable/c/33f341c1fc60e172a3515c51bdabee11e83d1ee9","https://git.kernel.org/stable/c/3bc7324e4911351e39c54a62e6ca46321cb10faf","https://git.kernel.org/stable/c/3e016ef2e72da93a2ea7afbb45de1b481b44d761"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:01:22.920403922+00:00"},"epss":{"cve":"CVE-2023-53045","score":0.00153,"percentile":0.04458,"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."]}