CyberSecBulletin
CVE-2022-50094NVD status: Analyzed

Linux: Out-of-bounds Read

Published Updated By the CyberSecBulletin desk

CVE-2022-50094 is a high-severity out-of-bounds read vulnerability in Linux, with a CVSS 3.1 base score of 7.1 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions 80f7c93e573ea9f524924bb529c2af8cb28b1c43, dc6033a7761254e5a5ba7df36b64db787a53313c, ac730c72bddc889f5610d51d8a7abf425e08da1a as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.28% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Linux to 80f7c93e573ea9f524924bb529c2af8cb28b1c43 or dc6033a7761254e5a5ba7df36b64db787a53313c or ac730c72bddc889f5610d51d8a7abf425e08da1a or 37690cb8662cec672cacda19e6e4fd2ca7b13f0b, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 4.9.326 or 4.14.291 or 4.19.256 or 5.4.211, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinuxa9fce374815d8ab94a3e6259802a944e2cc21408 up to, but not including, 80f7c93e573ea9f524924bb529c2af8cb28b1c43; a9fce374815d8ab94a3e6259802a944e2cc21408 up to, but not including, dc6033a7761254e5a5ba7df36b64db787a53313c; a9fce374815d8ab94a3e6259802a944e2cc21408 up to, but not including, ac730c72bddc889f5610d51d8a7abf425e08da1a; a9fce374815d8ab94a3e6259802a944e2cc21408 up to, but not including, 37690cb8662cec672cacda19e6e4fd2ca7b13f0b; a9fce374815d8ab94a3e6259802a944e2cc21408 up to, but not including, dd02510fb43168310abfd0b9ccf49993a722fb91; a9fce374815d8ab94a3e6259802a944e2cc21408 up to, but not including, 1e0ca3d809c36ad3d1f542917718fc22ec6316e7; a9fce374815d8ab94a3e6259802a944e2cc21408 up to, but not including, bcc1b6b1ed3f42ed25858c1f1eb24a2f741db93f; a9fce374815d8ab94a3e6259802a944e2cc21408 up to, but not including, 504090815c1ad3fd3fa34618b54d706727f8911c; and 2 more ranges80f7c93e573ea9f524924bb529c2af8cb28b1c43, dc6033a7761254e5a5ba7df36b64db787a53313c, ac730c72bddc889f5610d51d8a7abf425e08da1a, 37690cb8662cec672cacda19e6e4fd2ca7b13f0b, dd02510fb43168310abfd0b9ccf49993a722fb91, 1e0ca3d809c36ad3d1f542917718fc22ec6316e7
LinuxLinux Kernel4.3 up to, but not including, 4.9.326; 4.10 up to, but not including, 4.14.291; 4.15 up to, but not including, 4.19.256; 4.20 up to, but not including, 5.4.211; 5.5 up to, but not including, 5.10.137; 5.11 up to, but not including, 5.15.61; 5.16 up to, but not including, 5.18.18; 5.19 up to, but not including, 5.19.24.9.326, 4.14.291, 4.19.256, 5.4.211, 5.10.137, 5.15.61

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
NoneNothing can be modified.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H. Scored by NVD.

Official description

In the Linux kernel, the following vulnerability has been resolved: spmi: trace: fix stack-out-of-bound access in SPMI tracing functions trace_spmi_write_begin() and trace_spmi_read_end() both call memcpy() with a length of "len + 1". This leads to one extra byte being read beyond the end of the specified buffer. Fix this out-of-bound memory access by using a length of "len" instead. Here is a KASAN log showing the issue: BUG: KASAN: stack-out-of-bounds in trace_event_raw_event_spmi_read_end+0x1d0/0x234 Read of size 2 at addr ffffffc0265b7540 by task [email protected]/1314 ... Call trace: dump_backtrace+0x0/0x3e8 show_stack+0x2c/0x3c dump_stack_lvl+0xdc/0x11c print_address_description+0x74/0x384 kasan_report+0x188/0x268 kasan_check_range+0x270/0x2b0 memcpy+0x90/0xe8 trace_event_raw_event_spmi_read_end+0x1d0/0x234 spmi_read_cmd+0x294/0x3ac spmi_ext_register_readl+0x84/0x9c regmap_spmi_ext_read+0x144/0x1b0 [regmap_spmi] _regmap_raw_read+0x40c/0x754 regmap_raw_read+0x3a0/0x514 regmap_bulk_read+0x418/0x494 adc5_gen3_poll_wait_hs+0xe8/0x1e0 [qcom_spmi_adc5_gen3] ... __arm64_sys_read+0x4c/0x60 invoke_syscall+0x80/0x218 el0_svc_common+0xec/0x1c8 ... addr ffffffc0265b7540 is located in stack of task [email protected]/1314 at offset 32 in frame: adc5_gen3_poll_wait_hs+0x0/0x1e0 [qcom_spmi_adc5_gen3] this frame has 1 object: [32, 33) 'status' Memory state around the buggy address: ffffffc0265b7400: 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1 ffffffc0265b7480: 04 f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00 00 >ffffffc0265b7500: 00 00 00 00 f1 f1 f1 f1 01 f3 f3 f3 00 00 00 00 ^ ffffffc0265b7580: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffffffc0265b7600: f1 f1 f1 f1 01 f2 07 f2 f2 f2 01 f3 00 00 00 00 ==================================================================

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Out-of-bounds Read

The product reads data past the end, or before the beginning, of the intended buffer.

How developers prevent this class of flaw

  • Use a language that provides appropriate memory abstractions.

More Out-of-bounds Read vulnerabilities (CWE-125)

Timeline

  1. CVE record published.
  2. Record last changed materially (score, affected products, status or references).

References

Recent Out-of-bounds Read vulnerabilities

Spotted an error? Tell us.