{ "data_version": "4.0", "data_type": "CVE", "data_format": "MITRE", "CVE_data_meta": { "ID": "CVE-2022-48629", "ASSIGNER": "cve@kernel.org", "STATE": "PUBLIC" }, "description": { "description_data": [ { "lang": "eng", "value": "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 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 \ufffd 32883 0.003654\n 254 \ufffd 33035 0.003671\n 255 \ufffd 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 \ufffd 35201 0.003911\n 254 \ufffd 34835 0.003871\n 255 \ufffd 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)." } ] }, "problemtype": { "problemtype_data": [ { "description": [ { "lang": "eng", "value": "n/a" } ] } ] }, "affects": { "vendor": { "vendor_data": [ { "vendor_name": "Linux", "product": { "product_data": [ { "product_name": "Linux", "version": { "version_data": [ { "version_affected": "<", "version_name": "ceec5f5b5988", "version_value": "a8e32bbb96c2" }, { "version_value": "not down converted", "x_cve_json_5_version_data": { "versions": [ { "version": "4.19", "status": "affected" }, { "version": "0", "lessThan": "4.19", "status": "unaffected", "versionType": "custom" }, { "version": "4.19.236", "lessThanOrEqual": "4.19.*", "status": "unaffected", "versionType": "custom" }, { "version": "5.4.187", "lessThanOrEqual": "5.4.*", "status": "unaffected", "versionType": "custom" }, { "version": "5.10.108", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "custom" }, { "version": "5.15.31", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "custom" }, { "version": "5.16.17", "lessThanOrEqual": "5.16.*", "status": "unaffected", "versionType": "custom" }, { "version": "5.17", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ], "defaultStatus": "affected" } } ] } } ] } } ] } }, "references": { "reference_data": [ { "url": "https://git.kernel.org/stable/c/a8e32bbb96c25b7ab29b1894dcd45e0b3b08fd9d", "refsource": "MISC", "name": "https://git.kernel.org/stable/c/a8e32bbb96c25b7ab29b1894dcd45e0b3b08fd9d" }, { "url": "https://git.kernel.org/stable/c/184f7bd08ce56f003530fc19f160d54e75bf5c9d", "refsource": "MISC", "name": "https://git.kernel.org/stable/c/184f7bd08ce56f003530fc19f160d54e75bf5c9d" }, { "url": "https://git.kernel.org/stable/c/0f9b7b8df17525e464294c916acc8194ce38446b", "refsource": "MISC", "name": "https://git.kernel.org/stable/c/0f9b7b8df17525e464294c916acc8194ce38446b" }, { "url": "https://git.kernel.org/stable/c/ab9337c7cb6f875b6286440b1adfbeeef2b2b2bd", "refsource": "MISC", "name": "https://git.kernel.org/stable/c/ab9337c7cb6f875b6286440b1adfbeeef2b2b2bd" }, { "url": "https://git.kernel.org/stable/c/485995cbc98a4f77cfd4f8ed4dd7ff8ab262964d", "refsource": "MISC", "name": "https://git.kernel.org/stable/c/485995cbc98a4f77cfd4f8ed4dd7ff8ab262964d" }, { "url": "https://git.kernel.org/stable/c/a680b1832ced3b5fa7c93484248fd221ea0d614b", "refsource": "MISC", "name": "https://git.kernel.org/stable/c/a680b1832ced3b5fa7c93484248fd221ea0d614b" } ] }, "generator": { "engine": "bippy-a5840b7849dd" } }