CVE-2022-49767

Aliases:UBUNTU-CVE-2022-49767DEBIAN-CVE-2022-49767
Advisory lineage Upstream: 0 Downstream: 8
Analyzed
Published: 01 May 2025, 14:09
Last modified:11 May 2026, 19:06

Vulnerability Summary

Overall Risk (default)
low
22/100
CVSS Score
5.5 MEDIUM
v3.1 (nvd)
EPSS Score
0.19% LOW
0% probability +0.18%
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

01 May 2025, 14:09
Published
Vulnerability first disclosed
11 May 2026, 19:06
Last Modified
Vulnerability information updated

Description

In the Linux kernel, the following vulnerability has been resolved: 9p/trans_fd: always use O_NONBLOCK read/write syzbot is reporting hung task at p9_fd_close() [1], for p9_mux_poll_stop() from p9_conn_destroy() from p9_fd_close() is failing to interrupt already started kernel_read() from p9_fd_read() from p9_read_work() and/or kernel_write() from p9_fd_write() from p9_write_work() requests. Since p9_socket_open() sets O_NONBLOCK flag, p9_mux_poll_stop() does not need to interrupt kernel_read()/kernel_write(). However, since p9_fd_open() does not set O_NONBLOCK flag, but pipe blocks unless signal is pending, p9_mux_poll_stop() needs to interrupt kernel_read()/kernel_write() when the file descriptor refers to a pipe. In other words, pipe file descriptor needs to be handled as if socket file descriptor. We somehow need to interrupt kernel_read()/kernel_write() on pipes. A minimal change, which this patch is doing, is to set O_NONBLOCK flag from p9_fd_open(), for O_NONBLOCK flag does not affect reading/writing of regular files. But this approach changes O_NONBLOCK flag on userspace- supplied file descriptors (which might break userspace programs), and O_NONBLOCK flag could be changed by userspace. It would be possible to set O_NONBLOCK flag every time p9_fd_read()/p9_fd_write() is invoked, but still remains small race window for clearing O_NONBLOCK flag. If we don't want to manipulate O_NONBLOCK flag, we might be able to surround kernel_read()/kernel_write() with set_thread_flag(TIF_SIGPENDING) and recalc_sigpending(). Since p9_read_work()/p9_write_work() works are processed by kernel threads which process global system_wq workqueue, signals could not be delivered from remote threads when p9_mux_poll_stop() from p9_conn_destroy() from p9_fd_close() is called. Therefore, calling set_thread_flag(TIF_SIGPENDING)/recalc_sigpending() every time would be needed if we count on signals for making kernel_read()/kernel_write() non-blocking. [Dominique: add comment at Christian's suggestion]

CVSS Metrics

  • v3.1•MEDIUM•Score: 5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS Trends

Current EPSS score: 0.19%• Percentile: 10%

Affected Systems

  • debian•linux

    < 5.10.158-1 | < 6.0.10-1 | < 6.0.10-1 | < 6.0.10-1

  • ubuntu•linux

    all | < 4.15.0-206.217 | < 5.4.0-144.161 | < 5.15.0-67.74

  • ubuntu•linux-allwinner-5.19

    all

  • ubuntu•linux-aws

    all | < 4.15.0-1151.164 | < 5.4.0-1097.105 | < 5.15.0-1031.35

  • ubuntu•linux-aws-5.0

    all

  • ubuntu•linux-aws-5.11

    all

  • ubuntu•linux-aws-5.13

    all

  • ubuntu•linux-aws-5.15

    < 5.15.0-1031.35~20.04.1

  • ubuntu•linux-aws-5.19

    all

  • ubuntu•linux-aws-5.3

    all

  • ubuntu•linux-aws-5.4

    < 5.4.0-1097.105~18.04.1

  • ubuntu•linux-aws-5.8

    all

  • ubuntu•linux-aws-6.2

    all

  • ubuntu•linux-aws-6.5

    all

  • ubuntu•linux-aws-fips

    < 4.15.0-2090.96 | all | < 5.4.0-1099.107+fips1

  • ubuntu•linux-aws-hwe

    < 4.15.0-1151.164~16.04.1

  • ubuntu•linux-azure

    < 4.15.0-1162.177~14.04.1 | < 4.15.0-1162.177~16.04.1 | all | < 5.4.0-1104.110 | < 5.15.0-1034.41

  • ubuntu•linux-azure-4.15

    < 4.15.0-1162.177

  • ubuntu•linux-azure-5.11

    all

  • ubuntu•linux-azure-5.13

    all

  • ubuntu•linux-azure-5.15

    < 5.15.0-1034.41~20.04.1

  • ubuntu•linux-azure-5.19

    all

  • ubuntu•linux-azure-5.3

    all

  • ubuntu•linux-azure-5.4

    < 5.4.0-1104.110~18.04.1

  • ubuntu•linux-azure-5.8

    all

  • ubuntu•linux-azure-6.2

    all

  • ubuntu•linux-azure-6.5

    all

  • ubuntu•linux-azure-edge

    all

  • ubuntu•linux-azure-fde

    all | all

  • ubuntu•linux-azure-fde-5.15

    < 5.15.0-1114.123~20.04.1

  • ubuntu•linux-azure-fde-5.19

    all

  • ubuntu•linux-azure-fde-6.2

    all

  • ubuntu•linux-azure-fips

    < 4.15.0-2071.77 | all | < 5.4.0-1104.110+fips1

  • ubuntu•linux-bluefield

    all | < 5.4.0-1059.65 | < 5.15.0-1014.16

  • ubuntu•linux-fips

    all | < 4.15.0-1108.119 | < 5.4.0-1073.82

  • ubuntu•linux-gcp

    < 4.15.0-1146.162~16.04.1 | all | < 5.4.0-1101.110 | < 5.15.0-1030.37

  • ubuntu•linux-gcp-4.15

    < 4.15.0-1146.162

  • ubuntu•linux-gcp-5.11

    all

  • ubuntu•linux-gcp-5.13

    all

  • ubuntu•linux-gcp-5.15

    < 5.15.0-1030.37~20.04.1

  • ubuntu•linux-gcp-5.19

    all

  • ubuntu•linux-gcp-5.3

    all

  • ubuntu•linux-gcp-5.4

    < 5.4.0-1101.110~18.04.1

  • ubuntu•linux-gcp-5.8

    all

  • ubuntu•linux-gcp-6.2

    all

  • ubuntu•linux-gcp-6.5

    all

  • ubuntu•linux-gcp-fips

    < 4.15.0-2055.60 | all | < 5.4.0-1101.110+fips1

  • ubuntu•linux-gke

    all | < 5.15.0-1028.33

  • ubuntu•linux-gke-4.15

    all

  • ubuntu•linux-gke-5.15

    all

Showing first 50 affected entries in server-rendered view.

References (12)