CVE-ID

CVE-2021-47582

• CVSS Severity Rating • Fix Information • Vulnerable Software Versions • SCAP Mappings • CPE Information
Description
In the Linux kernel, the following vulnerability has been resolved: USB: core: Make do_proc_control() and do_proc_bulk() killable The USBDEVFS_CONTROL and USBDEVFS_BULK ioctls invoke usb_start_wait_urb(), which contains an uninterruptible wait with a user-specified timeout value. If timeout value is very large and the device being accessed does not respond in a reasonable amount of time, the kernel will complain about "Task X blocked for more than N seconds", as found in testing by syzbot: INFO: task syz-executor.0:8700 blocked for more than 143 seconds. Not tainted 5.14.0-rc7-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:23192 pid: 8700 ppid: 8455 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4681 [inline] __schedule+0xc07/0x11f0 kernel/sched/core.c:5938 schedule+0x14b/0x210 kernel/sched/core.c:6017 schedule_timeout+0x98/0x2f0 kernel/time/timer.c:1857 do_wait_for_common+0x2da/0x480 kernel/sched/completion.c:85 __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion_timeout+0x46/0x60 kernel/sched/completion.c:157 usb_start_wait_urb+0x167/0x550 drivers/usb/core/message.c:63 do_proc_bulk+0x978/0x1080 drivers/usb/core/devio.c:1236 proc_bulk drivers/usb/core/devio.c:1273 [inline] usbdev_do_ioctl drivers/usb/core/devio.c:2547 [inline] usbdev_ioctl+0x3441/0x6b10 drivers/usb/core/devio.c:2713 ... To fix this problem, this patch replaces usbfs's calls to usb_control_msg() and usb_bulk_msg() with special-purpose code that does essentially the same thing (as recommended in the comment for usb_start_wait_urb()), except that it always uses a killable wait and it uses GFP_KERNEL rather than GFP_NOIO.
References
Note: References are provided for the convenience of the reader to help distinguish between vulnerabilities. The list is not intended to be complete.
Assigning CNA
kernel.org
Date Record Created
20240524 Disclaimer: The record creation date may reflect when the CVE ID was allocated or reserved, and does not necessarily indicate when this vulnerability was discovered, shared with the affected vendor, publicly disclosed, or updated in CVE.
Phase (Legacy)
Assigned (20240524)
Votes (Legacy)
Comments (Legacy)
Proposed (Legacy)
N/A
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