crypto: qcom-rng - ensure buffer for generate is completely filled

Description

In the Linux kernel, the following vulnerability has been resolved: crypto: qcom-rng - ensure buffer for generate is completely filled The generate function in struct rng_alg expects that the destination buffer is completely filled if the function returns 0. qcom_rng_read() can run into a situation where the buffer is partially filled with randomness and the remaining part of the buffer is zeroed since qcom_rng_generate() doesn't check the return value. This issue can be reproduced by running the following from libkcapi: kcapi-rng -b 9000000 > OUTFILE The generated OUTFILE will have three huge sections that contain all zeros, and this is caused by the code where the test 'val & PRNG_STATUS_DATA_AVAIL' fails. Let's fix this issue by ensuring that qcom_rng_read() always returns with a full buffer if the function returns success. Let's also have qcom_rng_generate() return the correct value. Here's some statistics from the ent project (https://www.fourmilab.ch/random/) that shows information about the quality of the generated numbers: $ ent -c qcom-random-before Value Char Occurrences Fraction 0 606748 0.067416 1 33104 0.003678 2 33001 0.003667 ... 253 � 32883 0.003654 254 � 33035 0.003671 255 � 33239 0.003693 Total: 9000000 1.000000 Entropy = 7.811590 bits per byte. Optimum compression would reduce the size of this 9000000 byte file by 2 percent. Chi square distribution for 9000000 samples is 9329962.81, and randomly would exceed this value less than 0.01 percent of the times. Arithmetic mean value of data bytes is 119.3731 (127.5 = random). Monte Carlo value for Pi is 3.197293333 (error 1.77 percent). Serial correlation coefficient is 0.159130 (totally uncorrelated = 0.0). Without this patch, the results of the chi-square test is 0.01%, and the numbers are certainly not random according to ent's project page. The results improve with this patch: $ ent -c qcom-random-after Value Char Occurrences Fraction 0 35432 0.003937 1 35127 0.003903 2 35424 0.003936 ... 253 � 35201 0.003911 254 � 34835 0.003871 255 � 35368 0.003930 Total: 9000000 1.000000 Entropy = 7.999979 bits per byte. Optimum compression would reduce the size of this 9000000 byte file by 0 percent. Chi square distribution for 9000000 samples is 258.77, and randomly would exceed this value 42.24 percent of the times. Arithmetic mean value of data bytes is 127.5006 (127.5 = random). Monte Carlo value for Pi is 3.141277333 (error 0.01 percent). Serial correlation coefficient is 0.000468 (totally uncorrelated = 0.0). This change was tested on a Nexus 5 phone (msm8974 SoC).

Scores

EPSS (exploitation in 30 days)

0.53% · top 55% of all CVEs (6 Nov 2026)

CISA SSVC

Exploitation: none · Automatable: no · Technical impact: partial

The list uses the assigner's score when there is one, then CISA's, then NVD's: High 8.1.

Affected products

• Linux · Linux

  • affected ceec5f5b59882b871a722ca4d49b767a09a4bde9 – < a8e32bbb96c25b7ab29b1894dcd45e0b3b08fd9d
  • affected ceec5f5b59882b871a722ca4d49b767a09a4bde9 – < 184f7bd08ce56f003530fc19f160d54e75bf5c9d
  • affected ceec5f5b59882b871a722ca4d49b767a09a4bde9 – < 0f9b7b8df17525e464294c916acc8194ce38446b
  • affected ceec5f5b59882b871a722ca4d49b767a09a4bde9 – < ab9337c7cb6f875b6286440b1adfbeeef2b2b2bd
  • affected ceec5f5b59882b871a722ca4d49b767a09a4bde9 – < 485995cbc98a4f77cfd4f8ed4dd7ff8ab262964d
  • affected ceec5f5b59882b871a722ca4d49b767a09a4bde9 – < a680b1832ced3b5fa7c93484248fd221ea0d614b

• Linux · Linux

  • affected 4.19
  • unaffected < 4.19
  • unaffected 4.19.236 – ≤ 4.19.*
  • unaffected 5.4.187 – ≤ 5.4.*
  • unaffected 5.10.108 – ≤ 5.10.*
  • unaffected 5.15.31 – ≤ 5.15.*
  • unaffected 5.16.17 – ≤ 5.16.*
  • unaffected 5.17 – ≤ *

References (6)

• https://git.kernel.org/stable/c/a8e32bbb96c25b7ab29b1894dcd45e0b3b08fd9d (opens in a new tab)x_transferred
• https://git.kernel.org/stable/c/184f7bd08ce56f003530fc19f160d54e75bf5c9d (opens in a new tab)x_transferred
• https://git.kernel.org/stable/c/0f9b7b8df17525e464294c916acc8194ce38446b (opens in a new tab)x_transferred
• https://git.kernel.org/stable/c/ab9337c7cb6f875b6286440b1adfbeeef2b2b2bd (opens in a new tab)x_transferred
• https://git.kernel.org/stable/c/485995cbc98a4f77cfd4f8ed4dd7ff8ab262964d (opens in a new tab)x_transferred
• https://git.kernel.org/stable/c/a680b1832ced3b5fa7c93484248fd221ea0d614b (opens in a new tab)x_transferred

Sources

The same CVE in the primary databases and aggregators, to check against.

• CVE.org record (opens in a new tab)
• CVE List JSON (GitHub) (opens in a new tab)
• NVD (opens in a new tab)
• FIRST EPSS (opens in a new tab)
• OSV.dev (opens in a new tab)
• GitHub Advisories (opens in a new tab)
• CIRCL Vulnerability-Lookup (opens in a new tab)

Badge for a README or a ticket

[![CVE-2022-48629](https://trackcve.app/badge/CVE-2022-48629.svg)](https://trackcve.app/cve/CVE-2022-48629)

Record last updated 5 Aug 2026, 08:51 UTC.