{"id":"CVE-2022-49771","state":"PUBLISHED","title":"dm ioctl: fix misbehavior if list_versions races with module loading","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ndm ioctl: fix misbehavior if list_versions races with module loading\n\n__list_versions will first estimate the required space using the\n\"dm_target_iterate(list_version_get_needed, &needed)\" call and then will\nfill the space using the \"dm_target_iterate(list_version_get_info,\n&iter_info)\" call. Each of these calls locks the targets using the\n\"down_read(&_lock)\" and \"up_read(&_lock)\" calls, however between the first\nand second \"dm_target_iterate\" there is no lock held and the target\nmodules can be loaded at this point, so the second \"dm_target_iterate\"\ncall may need more space than what was the first \"dm_target_iterate\"\nreturned.\n\nThe code tries to handle this overflow (see the beginning of\nlist_version_get_info), however this handling is incorrect.\n\nThe code sets \"param->data_size = param->data_start + needed\" and\n\"iter_info.end = (char *)vers+len\" - \"needed\" is the size returned by the\nfirst dm_target_iterate call; \"len\" is the size of the buffer allocated by\nuserspace.\n\n\"len\" may be greater than \"needed\"; in this case, the code will write up\nto \"len\" bytes into the buffer, however param->data_size is set to\n\"needed\", so it may write data past the param->data_size value. The ioctl\ninterface copies only up to param->data_size into userspace, thus part of\nthe result will be truncated.\n\nFix this bug by setting \"iter_info.end = (char *)vers + needed;\" - this\nguarantees that the second \"dm_target_iterate\" call will write only up to\nthe \"needed\" buffer and it will exit with \"DM_BUFFER_FULL_FLAG\" if it\noverflows the \"needed\" space - in this case, userspace will allocate a\nlarger buffer and retry.\n\nNote that there is also a bug in list_version_get_needed - we need to add\n\"strlen(tt->name) + 1\" to the needed size, not \"strlen(tt->name)\".","publishedAt":"2025-05-01T14:09:08.813Z","updatedAt":"2026-05-11T19:06:27.827Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"0c8d4112df329bf3dfbf27693f918c3b08676538","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"6a818db0d5aecf80d4ba9e10ac153f60adc629ca","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"3a1c35d72dc0b34d1e746ed705790c0f630aa427","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"b545c0e1e4094d4de2bdfe9a3823f9154b0c0005","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"f59f5a269ca5e43c567aca7f1f52500a0186e9b7","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"6ffce7a92ef5c68f7e5d6f4d722c2f96280c064b","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"5398b8e275bf81a2517b327d216c0f37ac9ac5ae","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"4fe1ec995483737f3d2a14c3fe1d8fe634972979","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/md/dm-ioctl.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.12","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.12","versionType":"semver"},{"version":"4.9.334","status":"unaffected","lessThanOrEqual":"4.9.*","versionType":"semver"},{"version":"4.14.300","status":"unaffected","lessThanOrEqual":"4.14.*","versionType":"semver"},{"version":"4.19.267","status":"unaffected","lessThanOrEqual":"4.19.*","versionType":"semver"},{"version":"5.4.225","status":"unaffected","lessThanOrEqual":"5.4.*","versionType":"semver"},{"version":"5.10.156","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.80","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.0.10","status":"unaffected","lessThanOrEqual":"6.0.*","versionType":"semver"},{"version":"6.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/md/dm-ioctl.c"]}],"references":["https://git.kernel.org/stable/c/0c8d4112df329bf3dfbf27693f918c3b08676538","https://git.kernel.org/stable/c/6a818db0d5aecf80d4ba9e10ac153f60adc629ca","https://git.kernel.org/stable/c/3a1c35d72dc0b34d1e746ed705790c0f630aa427","https://git.kernel.org/stable/c/b545c0e1e4094d4de2bdfe9a3823f9154b0c0005","https://git.kernel.org/stable/c/f59f5a269ca5e43c567aca7f1f52500a0186e9b7","https://git.kernel.org/stable/c/6ffce7a92ef5c68f7e5d6f4d722c2f96280c064b","https://git.kernel.org/stable/c/5398b8e275bf81a2517b327d216c0f37ac9ac5ae","https://git.kernel.org/stable/c/4fe1ec995483737f3d2a14c3fe1d8fe634972979"],"weaknesses":[],"ingestedAt":"2026-10-29T20:05:26.763Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2022/49xxx/CVE-2022-49771.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2022-49771","state":"PUBLISHED","datePublished":"2025-05-01T14:09:08.813Z","dateUpdated":"2026-05-11T19:06:27.827Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2025-04-16T07:17:33.805Z"},"containers":{"cna":{"title":"dm ioctl: fix misbehavior if list_versions races with module loading","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ndm ioctl: fix misbehavior if list_versions races with module loading\n\n__list_versions will first estimate the required space using the\n\"dm_target_iterate(list_version_get_needed, &needed)\" call and then will\nfill the space using the \"dm_target_iterate(list_version_get_info,\n&iter_info)\" call. Each of these calls locks the targets using the\n\"down_read(&_lock)\" and \"up_read(&_lock)\" calls, however between the first\nand second \"dm_target_iterate\" there is no lock held and the target\nmodules can be loaded at this point, so the second \"dm_target_iterate\"\ncall may need more space than what was the first \"dm_target_iterate\"\nreturned.\n\nThe code tries to handle this overflow (see the beginning of\nlist_version_get_info), however this handling is incorrect.\n\nThe code sets \"param->data_size = param->data_start + needed\" and\n\"iter_info.end = (char *)vers+len\" - \"needed\" is the size returned by the\nfirst dm_target_iterate call; \"len\" is the size of the buffer allocated by\nuserspace.\n\n\"len\" may be greater than \"needed\"; in this case, the code will write up\nto \"len\" bytes into the buffer, however param->data_size is set to\n\"needed\", so it may write data past the param->data_size value. The ioctl\ninterface copies only up to param->data_size into userspace, thus part of\nthe result will be truncated.\n\nFix this bug by setting \"iter_info.end = (char *)vers + needed;\" - this\nguarantees that the second \"dm_target_iterate\" call will write only up to\nthe \"needed\" buffer and it will exit with \"DM_BUFFER_FULL_FLAG\" if it\noverflows the \"needed\" space - in this case, userspace will allocate a\nlarger buffer and retry.\n\nNote that there is also a bug in list_version_get_needed - we need to add\n\"strlen(tt->name) + 1\" to the needed size, not \"strlen(tt->name)\"."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"0c8d4112df329bf3dfbf27693f918c3b08676538","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"6a818db0d5aecf80d4ba9e10ac153f60adc629ca","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"3a1c35d72dc0b34d1e746ed705790c0f630aa427","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"b545c0e1e4094d4de2bdfe9a3823f9154b0c0005","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"f59f5a269ca5e43c567aca7f1f52500a0186e9b7","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"6ffce7a92ef5c68f7e5d6f4d722c2f96280c064b","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"5398b8e275bf81a2517b327d216c0f37ac9ac5ae","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"4fe1ec995483737f3d2a14c3fe1d8fe634972979","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/md/dm-ioctl.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.12","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.12","versionType":"semver"},{"version":"4.9.334","status":"unaffected","lessThanOrEqual":"4.9.*","versionType":"semver"},{"version":"4.14.300","status":"unaffected","lessThanOrEqual":"4.14.*","versionType":"semver"},{"version":"4.19.267","status":"unaffected","lessThanOrEqual":"4.19.*","versionType":"semver"},{"version":"5.4.225","status":"unaffected","lessThanOrEqual":"5.4.*","versionType":"semver"},{"version":"5.10.156","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.80","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.0.10","status":"unaffected","lessThanOrEqual":"6.0.*","versionType":"semver"},{"version":"6.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/md/dm-ioctl.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/0c8d4112df329bf3dfbf27693f918c3b08676538"},{"url":"https://git.kernel.org/stable/c/6a818db0d5aecf80d4ba9e10ac153f60adc629ca"},{"url":"https://git.kernel.org/stable/c/3a1c35d72dc0b34d1e746ed705790c0f630aa427"},{"url":"https://git.kernel.org/stable/c/b545c0e1e4094d4de2bdfe9a3823f9154b0c0005"},{"url":"https://git.kernel.org/stable/c/f59f5a269ca5e43c567aca7f1f52500a0186e9b7"},{"url":"https://git.kernel.org/stable/c/6ffce7a92ef5c68f7e5d6f4d722c2f96280c064b"},{"url":"https://git.kernel.org/stable/c/5398b8e275bf81a2517b327d216c0f37ac9ac5ae"},{"url":"https://git.kernel.org/stable/c/4fe1ec995483737f3d2a14c3fe1d8fe634972979"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-05-11T19:06:27.827Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"4.9.334"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"4.14.300"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"4.19.267"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"5.4.225"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"5.10.156"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"5.15.80"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"6.0.10"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"6.1"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}