vulnerability

Alma Linux: CVE-2021-47582: Important: kernel security update (Multiple Advisories)

Severity
5
CVSS
(AV:L/AC:L/Au:S/C:N/I:N/A:C)
Published
Jun 19, 2024
Added
Sep 26, 2024
Modified
Nov 13, 2025

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.

Solutions

alma-upgrade-bpftoolalma-upgrade-kernelalma-upgrade-kernel-abi-stablelistsalma-upgrade-kernel-corealma-upgrade-kernel-cross-headersalma-upgrade-kernel-debugalma-upgrade-kernel-debug-corealma-upgrade-kernel-debug-develalma-upgrade-kernel-debug-modulesalma-upgrade-kernel-debug-modules-extraalma-upgrade-kernel-develalma-upgrade-kernel-docalma-upgrade-kernel-headersalma-upgrade-kernel-modulesalma-upgrade-kernel-modules-extraalma-upgrade-kernel-rtalma-upgrade-kernel-rt-corealma-upgrade-kernel-rt-debugalma-upgrade-kernel-rt-debug-corealma-upgrade-kernel-rt-debug-develalma-upgrade-kernel-rt-debug-kvmalma-upgrade-kernel-rt-debug-modulesalma-upgrade-kernel-rt-debug-modules-extraalma-upgrade-kernel-rt-develalma-upgrade-kernel-rt-kvmalma-upgrade-kernel-rt-modulesalma-upgrade-kernel-rt-modules-extraalma-upgrade-kernel-toolsalma-upgrade-kernel-tools-libsalma-upgrade-kernel-tools-libs-develalma-upgrade-kernel-zfcpdumpalma-upgrade-kernel-zfcpdump-corealma-upgrade-kernel-zfcpdump-develalma-upgrade-kernel-zfcpdump-modulesalma-upgrade-kernel-zfcpdump-modules-extraalma-upgrade-perfalma-upgrade-python3-perf
Title
NEW

Explore Exposure Command

Confidently identify and prioritize exposures from endpoint to cloud with full attack surface visibility and threat-aware risk context.