{"cve":"CVE-2021-47582","nvd":{"published":"2024-06-19T15:15:52.743","modified":"2026-06-17T04:17:48.627","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nUSB: core: Make do_proc_control() and do_proc_bulk() killable\n\nThe USBDEVFS_CONTROL and USBDEVFS_BULK ioctls invoke\nusb_start_wait_urb(), which contains an uninterruptible wait with a\nuser-specified timeout value.  If timeout value is very large and the\ndevice being accessed does not respond in a reasonable amount of time,\nthe kernel will complain about \"Task X blocked for more than N\nseconds\", as found in testing by syzbot:\n\nINFO: task syz-executor.0:8700 blocked for more than 143 seconds.\n      Not tainted 5.14.0-rc7-syzkaller #0\n\"echo 0 > /proc/sys/kernel/hung_task_timeout_secs\" disables this message.\ntask:syz-executor.0  state:D stack:23192 pid: 8700 ppid:  8455 flags:0x00004004\nCall Trace:\n context_switch kernel/sched/core.c:4681 [inline]\n __schedule+0xc07/0x11f0 kernel/sched/core.c:5938\n schedule+0x14b/0x210 kernel/sched/core.c:6017\n schedule_timeout+0x98/0x2f0 kernel/time/timer.c:1857\n do_wait_for_common+0x2da/0x480 kernel/sched/completion.c:85\n __wait_for_common kernel/sched/completion.c:106 [inline]\n wait_for_common kernel/sched/completion.c:117 [inline]\n wait_for_completion_timeout+0x46/0x60 kernel/sched/completion.c:157\n usb_start_wait_urb+0x167/0x550 drivers/usb/core/message.c:63\n do_proc_bulk+0x978/0x1080 drivers/usb/core/devio.c:1236\n proc_bulk drivers/usb/core/devio.c:1273 [inline]\n usbdev_do_ioctl drivers/usb/core/devio.c:2547 [inline]\n usbdev_ioctl+0x3441/0x6b10 drivers/usb/core/devio.c:2713\n...\n\nTo fix this problem, this patch replaces usbfs's calls to\nusb_control_msg() and usb_bulk_msg() with special-purpose code that\ndoes essentially the same thing (as recommended in the comment for\nusb_start_wait_urb()), except that it always uses a killable wait and\nit uses GFP_KERNEL rather than GFP_NOIO.","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":[],"references":["https://git.kernel.org/stable/c/403716741c6c2c510dce44e88f085a740f535de6","https://git.kernel.org/stable/c/ae8709b296d80c7f45aa1f35c0e7659ad69edce1","https://git.kernel.org/stable/c/403716741c6c2c510dce44e88f085a740f535de6","https://git.kernel.org/stable/c/ae8709b296d80c7f45aa1f35c0e7659ad69edce1"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:52:00.836172422+00:00"},"epss":{"cve":"CVE-2021-47582","score":0.00198,"percentile":0.09669,"date":"2026-10-31"},"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."]}