{"id":"CVE-2022-48629","title":"In the Linux kernel, the following vulnerability has been resolved:\n\ncrypto: qcom-rng - ensure buffer for generate is completely filled\n\nThe generate function in struct rng_alg expects that the destination\nbuffer is completely filled if …","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\ncrypto: qcom-rng - ensure buffer for generate is completely filled\n\nThe generate function in struct rng_alg expects that the destination\nbuffer is completely filled if …","severity":"high","cvss":8.1,"cvssVector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","vendor":"linux","product":"linux_kernel","affected":["linux_kernel >= 4.19, < 4.19.236","linux_kernel >= 4.20, < 5.4.187","linux_kernel >= 5.5, < 5.10.108","linux_kernel >= 5.11, < 5.15.31","linux_kernel >= 5.16, < 5.16.17","linux_kernel = 5.17"],"patched":["linux_kernel 5.16.17"],"published":"2024-03-05","updated":"2026-08-04","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2022-48629","references":[{"url":"https://git.kernel.org/stable/c/0f9b7b8df17525e464294c916acc8194ce38446b","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/184f7bd08ce56f003530fc19f160d54e75bf5c9d","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/485995cbc98a4f77cfd4f8ed4dd7ff8ab262964d","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/a680b1832ced3b5fa7c93484248fd221ea0d614b","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/a8e32bbb96c25b7ab29b1894dcd45e0b3b08fd9d","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/ab9337c7cb6f875b6286440b1adfbeeef2b2b2bd","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/0f9b7b8df17525e464294c916acc8194ce38446b","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/184f7bd08ce56f003530fc19f160d54e75bf5c9d","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/485995cbc98a4f77cfd4f8ed4dd7ff8ab262964d","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/a680b1832ced3b5fa7c93484248fd221ea0d614b","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/a8e32bbb96c25b7ab29b1894dcd45e0b3b08fd9d","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/ab9337c7cb6f875b6286440b1adfbeeef2b2b2bd","label":"af854a3a-2127-422b-91ae-364da2661108"}],"tags":["nvd"],"epss":0.00535,"epssPercentile":0.43865,"ingestedAt":"2026-08-05T05:58:02.662Z","slug":"CVE-2022-48629","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\ncrypto: qcom-rng - ensure buffer for generate is completely filled\n\nThe generate function in struct rng_alg expects that the destination\nbuffer is completely filled if the function returns 0. qcom_rng_read()\ncan run into a situation where the buffer is partially filled with\nrandomness and the remaining part of the buffer is zeroed since\nqcom_rng_generate() doesn't check the return value. This issue can\nbe reproduced by running the following from libkcapi:\n\n    kcapi-rng -b 9000000 > OUTFILE\n\nThe generated OUTFILE will have three huge sections that contain all\nzeros, and this is caused by the code where the test\n'val & PRNG_STATUS_DATA_AVAIL' fails.\n\nLet's fix this issue by ensuring that qcom_rng_read() always returns\nwith a full buffer if the function returns success. Let's also have\nqcom_rng_generate() return the correct value.\n\nHere's some statistics from the ent project\n(https://www.fourmilab.ch/random/) that shows information about the\nquality of the generated numbers:\n\n    $ ent -c qcom-random-before\n    Value Char Occurrences Fraction\n      0           606748   0.067416\n      1            33104   0.003678\n      2            33001   0.003667\n    ...\n    253   �        32883   0.003654\n    254   �        33035   0.003671\n    255   �        33239   0.003693\n\n    Total:       9000000   1.000000\n\n    Entropy = 7.811590 bits per byte.\n\n    Optimum compression would reduce the size\n    of this 9000000 byte file by 2 percent.\n\n    Chi square distribution for 9000000 samples is 9329962.81, and\n    randomly would exceed this value less than 0.01 percent of the\n    times.\n\n    Arithmetic mean value of data bytes is 119.3731 (127.5 = random).\n    Monte Carlo value for Pi is 3.197293333 (error 1.77 percent).\n    Serial correlation coefficient is 0.159130 (totally uncorrelated =\n    0.0).\n\nWithout this patch, the results of the chi-square test is 0.01%, and\nthe numbers are certainly not random according to ent's project page.\nThe results improve with this patch:\n\n    $ ent -c qcom-random-after\n    Value Char Occurrences Fraction\n      0            35432   0.003937\n      1            35127   0.003903\n      2            35424   0.003936\n    ...\n    253   �        35201   0.003911\n    254   �        34835   0.003871\n    255   �        35368   0.003930\n\n    Total:       9000000   1.000000\n\n    Entropy = 7.999979 bits per byte.\n\n    Optimum compression would reduce the size\n    of this 9000000 byte file by 0 percent.\n\n    Chi square distribution for 9000000 samples is 258.77, and randomly\n    would exceed this value 42.24 percent of the times.\n\n    Arithmetic mean value of data bytes is 127.5006 (127.5 = random).\n    Monte Carlo value for Pi is 3.141277333 (error 0.01 percent).\n    Serial correlation coefficient is 0.000468 (totally uncorrelated =\n    0.0).\n\nThis change was tested on a Nexus 5 phone (msm8974 SoC).\n\n## Affected\n\n- `linux_kernel >= 4.19, < 4.19.236`\n- `linux_kernel >= 4.20, < 5.4.187`\n- `linux_kernel >= 5.5, < 5.10.108`\n- `linux_kernel >= 5.11, < 5.15.31`\n- `linux_kernel >= 5.16, < 5.16.17`\n- `linux_kernel = 5.17`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `linux_kernel 5.16.17`","depth":"twilight","depthScore":45,"depthScoreParts":{"impact":44.6,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}