CVE-2021-47089

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2021-47089", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-02-29T22:33:44.300Z", "datePublished": "2024-03-04T18:10:27.495Z", "dateUpdated": "2026-05-11T13:47:49.944Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-05-11T13:47:49.944Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nkfence: fix memory leak when cat kfence objects\n\nHulk robot reported a kmemleak problem:\n\n unreferenced object 0xffff93d1d8cc02e8 (size 248):\n comm \"cat\", pid 23327, jiffies 4624670141 (age 495992.217s)\n hex dump (first 32 bytes):\n 00 40 85 19 d4 93 ff ff 00 10 00 00 00 00 00 00 .@..............\n 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................\n backtrace:\n seq_open+0x2a/0x80\n full_proxy_open+0x167/0x1e0\n do_dentry_open+0x1e1/0x3a0\n path_openat+0x961/0xa20\n do_filp_open+0xae/0x120\n do_sys_openat2+0x216/0x2f0\n do_sys_open+0x57/0x80\n do_syscall_64+0x33/0x40\n entry_SYSCALL_64_after_hwframe+0x44/0xa9\n unreferenced object 0xffff93d419854000 (size 4096):\n comm \"cat\", pid 23327, jiffies 4624670141 (age 495992.217s)\n hex dump (first 32 bytes):\n 6b 66 65 6e 63 65 2d 23 32 35 30 3a 20 30 78 30 kfence-#250: 0x0\n 30 30 30 30 30 30 30 37 35 34 62 64 61 31 32 2d 0000000754bda12-\n backtrace:\n seq_read_iter+0x313/0x440\n seq_read+0x14b/0x1a0\n full_proxy_read+0x56/0x80\n vfs_read+0xa5/0x1b0\n ksys_read+0xa0/0xf0\n do_syscall_64+0x33/0x40\n entry_SYSCALL_64_after_hwframe+0x44/0xa9\n\nI find that we can easily reproduce this problem with the following\ncommands:\n\n\tcat /sys/kernel/debug/kfence/objects\n\techo scan > /sys/kernel/debug/kmemleak\n\tcat /sys/kernel/debug/kmemleak\n\nThe leaked memory is allocated in the stack below:\n\n do_syscall_64\n do_sys_open\n do_dentry_open\n full_proxy_open\n seq_open ---> alloc seq_file\n vfs_read\n full_proxy_read\n seq_read\n seq_read_iter\n traverse ---> alloc seq_buf\n\nAnd it should have been released in the following process:\n\n do_syscall_64\n syscall_exit_to_user_mode\n exit_to_user_mode_prepare\n task_work_run\n ____fput\n __fput\n full_proxy_release ---> free here\n\nHowever, the release function corresponding to file_operations is not\nimplemented in kfence. As a result, a memory leak occurs. Therefore,\nthe solution to this problem is to implement the corresponding release\nfunction."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["mm/kfence/core.c"], "versions": [{"version": "0ce20dd840897b12ae70869c69f1ba34d6d16965", "lessThan": "2f06c8293d27f6337f907042c602c9c953988c48", "status": "affected", "versionType": "git"}, {"version": "0ce20dd840897b12ae70869c69f1ba34d6d16965", "lessThan": "0129ab1f268b6cf88825eae819b9b84aa0a85634", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["mm/kfence/core.c"], "versions": [{"version": "5.12", "status": "affected"}, {"version": "0", "lessThan": "5.12", "status": "unaffected", "versionType": "semver"}, {"version": "5.15.12", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver"}, {"version": "5.16", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.12", "versionEndExcluding": "5.15.12"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.12", "versionEndExcluding": "5.16"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/2f06c8293d27f6337f907042c602c9c953988c48"}, {"url": "https://git.kernel.org/stable/c/0129ab1f268b6cf88825eae819b9b84aa0a85634"}], "title": "kfence: fix memory leak when cat kfence objects", "x_generator": {"engine": "bippy-1.2.0"}}, "adp": [{"problemTypes": [{"descriptions": [{"type": "CWE", "lang": "en", "description": "CWE-noinfo Not enough information"}]}], "affected": [{"vendor": "linux", "product": "linux_kernel", "cpes": ["cpe:2.3:o:linux:linux_kernel:-:*:*:*:*:*:*:*"], "defaultStatus": "unknown", "versions": [{"version": "0ce20dd84089", "status": "affected", "lessThan": "2f06c8293d27", "versionType": "custom"}, {"version": "0ce20dd84089", "status": "affected", "lessThan": "0129ab1f268b", "versionType": "custom"}, {"version": "5.12", "status": "affected"}, {"version": "0", "status": "affected", "lessThan": "5.12", "versionType": "custom"}, {"version": "5.15.12", "status": "affected", "lessThanOrEqual": "5.15*", "versionType": "custom"}, {"version": "5.16", "status": "affected", "lessThanOrEqual": "*", "versionType": "custom"}]}], "metrics": [{"cvssV3_1": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 3.3, "attackVector": "LOCAL", "baseSeverity": "LOW", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "LOW", "privilegesRequired": "LOW", "confidentialityImpact": "NONE"}}, {"other": {"type": "ssvc", "content": {"timestamp": "2024-10-31T13:23:25.318113Z", "id": "CVE-2021-47089", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "role": "CISA Coordinator", "version": "2.0.3"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-10-31T13:28:13.519Z"}}, {"providerMetadata": {"orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2024-08-04T05:24:39.939Z"}, "title": "CVE Program Container", "references": [{"url": "https://git.kernel.org/stable/c/2f06c8293d27f6337f907042c602c9c953988c48", "tags": ["x_transferred"]}, {"url": "https://git.kernel.org/stable/c/0129ab1f268b6cf88825eae819b9b84aa0a85634", "tags": ["x_transferred"]}]}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CVE Program Container", "references": [{"url": "https://git.kernel.org/stable/c/2f06c8293d27f6337f907042c602c9c953988c48", "tags": ["x_transferred"]}, {"url": "https://git.kernel.org/stable/c/0129ab1f268b6cf88825eae819b9b84aa0a85634", "tags": ["x_transferred"]}], "providerMetadata": {"orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2024-08-04T05:24:39.939Z"}}, {"title": "CISA ADP Vulnrichment", "metrics": [{"cvssV3_1": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 3.3, "attackVector": "LOCAL", "baseSeverity": "LOW", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "LOW", "privilegesRequired": "LOW", "confidentialityImpact": "NONE"}}, {"other": {"type": "ssvc", "content": {"id": "CVE-2021-47089", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2024-10-31T13:23:25.318113Z"}}}], "affected": [{"cpes": ["cpe:2.3:o:linux:linux_kernel:-:*:*:*:*:*:*:*"], "vendor": "linux", "product": "linux_kernel", "versions": [{"status": "affected", "version": "0ce20dd84089", "lessThan": "2f06c8293d27", "versionType": "custom"}, {"status": "affected", "version": "0ce20dd84089", "lessThan": "0129ab1f268b", "versionType": "custom"}, {"status": "affected", "version": "5.12"}, {"status": "affected", "version": "0", "lessThan": "5.12", "versionType": "custom"}, {"status": "affected", "version": "5.15.12", "versionType": "custom", "lessThanOrEqual": "5.15*"}, {"status": "affected", "version": "5.16", "versionType": "custom", "lessThanOrEqual": "*"}], "defaultStatus": "unknown"}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "description": "CWE-noinfo Not enough information"}]}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-07-24T14:25:51.167Z"}}], "cna": {"title": "kfence: fix memory leak when cat kfence objects", "affected": [{"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "0ce20dd840897b12ae70869c69f1ba34d6d16965", "lessThan": "2f06c8293d27f6337f907042c602c9c953988c48", "versionType": "git"}, {"status": "affected", "version": "0ce20dd840897b12ae70869c69f1ba34d6d16965", "lessThan": "0129ab1f268b6cf88825eae819b9b84aa0a85634", "versionType": "git"}], "programFiles": ["mm/kfence/core.c"], "defaultStatus": "unaffected"}, {"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "5.12"}, {"status": "unaffected", "version": "0", "lessThan": "5.12", "versionType": "semver"}, {"status": "unaffected", "version": "5.15.12", "versionType": "semver", "lessThanOrEqual": "5.15.*"}, {"status": "unaffected", "version": "5.16", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*"}], "programFiles": ["mm/kfence/core.c"], "defaultStatus": "affected"}], "references": [{"url": "https://git.kernel.org/stable/c/2f06c8293d27f6337f907042c602c9c953988c48"}, {"url": "https://git.kernel.org/stable/c/0129ab1f268b6cf88825eae819b9b84aa0a85634"}], "x_generator": {"engine": "bippy-1.2.0"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nkfence: fix memory leak when cat kfence objects\n\nHulk robot reported a kmemleak problem:\n\n unreferenced object 0xffff93d1d8cc02e8 (size 248):\n comm \"cat\", pid 23327, jiffies 4624670141 (age 495992.217s)\n hex dump (first 32 bytes):\n 00 40 85 19 d4 93 ff ff 00 10 00 00 00 00 00 00 .@..............\n 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................\n backtrace:\n seq_open+0x2a/0x80\n full_proxy_open+0x167/0x1e0\n do_dentry_open+0x1e1/0x3a0\n path_openat+0x961/0xa20\n do_filp_open+0xae/0x120\n do_sys_openat2+0x216/0x2f0\n do_sys_open+0x57/0x80\n do_syscall_64+0x33/0x40\n entry_SYSCALL_64_after_hwframe+0x44/0xa9\n unreferenced object 0xffff93d419854000 (size 4096):\n comm \"cat\", pid 23327, jiffies 4624670141 (age 495992.217s)\n hex dump (first 32 bytes):\n 6b 66 65 6e 63 65 2d 23 32 35 30 3a 20 30 78 30 kfence-#250: 0x0\n 30 30 30 30 30 30 30 37 35 34 62 64 61 31 32 2d 0000000754bda12-\n backtrace:\n seq_read_iter+0x313/0x440\n seq_read+0x14b/0x1a0\n full_proxy_read+0x56/0x80\n vfs_read+0xa5/0x1b0\n ksys_read+0xa0/0xf0\n do_syscall_64+0x33/0x40\n entry_SYSCALL_64_after_hwframe+0x44/0xa9\n\nI find that we can easily reproduce this problem with the following\ncommands:\n\n\tcat /sys/kernel/debug/kfence/objects\n\techo scan > /sys/kernel/debug/kmemleak\n\tcat /sys/kernel/debug/kmemleak\n\nThe leaked memory is allocated in the stack below:\n\n do_syscall_64\n do_sys_open\n do_dentry_open\n full_proxy_open\n seq_open ---> alloc seq_file\n vfs_read\n full_proxy_read\n seq_read\n seq_read_iter\n traverse ---> alloc seq_buf\n\nAnd it should have been released in the following process:\n\n do_syscall_64\n syscall_exit_to_user_mode\n exit_to_user_mode_prepare\n task_work_run\n ____fput\n __fput\n full_proxy_release ---> free here\n\nHowever, the release function corresponding to file_operations is not\nimplemented in kfence. As a result, a memory leak occurs. Therefore,\nthe solution to this problem is to implement the corresponding release\nfunction."}], "cpeApplicability": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "5.15.12", "versionStartIncluding": "5.12"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "5.16", "versionStartIncluding": "5.12"}], "operator": "OR"}]}], "providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2025-05-04T07:03:54.349Z"}}}, "cveMetadata": {"cveId": "CVE-2021-47089", "state": "PUBLISHED", "dateUpdated": "2025-05-04T07:03:54.349Z", "dateReserved": "2024-02-29T22:33:44.300Z", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "datePublished": "2024-03-04T18:10:27.495Z", "assignerShortName": "Linux"}, "dataVersion": "5.1"}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["mm/kfence/core.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "2f06c8293d27f6337f907042c602c9c953988c48", "status": "affected", "version": "0ce20dd840897b12ae70869c69f1ba34d6d16965", "versionType": "git"}, {"lessThan": "0129ab1f268b6cf88825eae819b9b84aa0a85634", "status": "affected", "version": "0ce20dd840897b12ae70869c69f1ba34d6d16965", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["mm/kfence/core.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "5.12"}, {"lessThan": "5.12", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "5.15.*", "status": "unaffected", "version": "5.15.12", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "5.16", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"affectedData": [{"cpes": ["cpe:2.3:o:linux:linux_kernel:-:*:*:*:*:*:*:*"], "defaultStatus": "unknown", "product": "linux_kernel", "vendor": "linux", "versions": [{"lessThan": "2f06c8293d27", "status": "affected", "version": "0ce20dd84089", "versionType": "custom"}, {"lessThan": "0129ab1f268b", "status": "affected", "version": "0ce20dd84089", "versionType": "custom"}, {"status": "affected", "version": "5.12"}, {"lessThan": "5.12", "status": "affected", "version": "0", "versionType": "custom"}, {"lessThanOrEqual": "5.15*", "status": "affected", "version": "5.15.12", "versionType": "custom"}, {"lessThanOrEqual": "*", "status": "affected", "version": "5.16", "versionType": "custom"}]}], "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "5CAD6D48-E560-4E57-93BC-36BEBD6A8FA6", "versionEndExcluding": "5.15.12", "versionStartIncluding": "5.12", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:5.16:rc1:*:*:*:*:*:*", "matchCriteriaId": "357AA433-37E8-4323-BFB2-3038D6E4B414", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:5.16:rc2:*:*:*:*:*:*", "matchCriteriaId": "A73429BA-C2D9-4D0C-A75F-06A1CA8B3983", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:5.16:rc3:*:*:*:*:*:*", "matchCriteriaId": "F621B5E3-E99D-49E7-90B9-EC3B77C95383", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:5.16:rc4:*:*:*:*:*:*", "matchCriteriaId": "F7BFDCAA-1650-49AA-8462-407DD593F94F", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:5.16:rc5:*:*:*:*:*:*", "matchCriteriaId": "6EC9882F-866D-4ACB-8FBC-213D8D8436C8", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:5.16:rc6:*:*:*:*:*:*", "matchCriteriaId": "8A0915FE-A4AA-4C94-B783-CF29D81E7E54", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nkfence: fix memory leak when cat kfence objects\n\nHulk robot reported a kmemleak problem:\n\n unreferenced object 0xffff93d1d8cc02e8 (size 248):\n comm \"cat\", pid 23327, jiffies 4624670141 (age 495992.217s)\n hex dump (first 32 bytes):\n 00 40 85 19 d4 93 ff ff 00 10 00 00 00 00 00 00 .@..............\n 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................\n backtrace:\n seq_open+0x2a/0x80\n full_proxy_open+0x167/0x1e0\n do_dentry_open+0x1e1/0x3a0\n path_openat+0x961/0xa20\n do_filp_open+0xae/0x120\n do_sys_openat2+0x216/0x2f0\n do_sys_open+0x57/0x80\n do_syscall_64+0x33/0x40\n entry_SYSCALL_64_after_hwframe+0x44/0xa9\n unreferenced object 0xffff93d419854000 (size 4096):\n comm \"cat\", pid 23327, jiffies 4624670141 (age 495992.217s)\n hex dump (first 32 bytes):\n 6b 66 65 6e 63 65 2d 23 32 35 30 3a 20 30 78 30 kfence-#250: 0x0\n 30 30 30 30 30 30 30 37 35 34 62 64 61 31 32 2d 0000000754bda12-\n backtrace:\n seq_read_iter+0x313/0x440\n seq_read+0x14b/0x1a0\n full_proxy_read+0x56/0x80\n vfs_read+0xa5/0x1b0\n ksys_read+0xa0/0xf0\n do_syscall_64+0x33/0x40\n entry_SYSCALL_64_after_hwframe+0x44/0xa9\n\nI find that we can easily reproduce this problem with the following\ncommands:\n\n\tcat /sys/kernel/debug/kfence/objects\n\techo scan > /sys/kernel/debug/kmemleak\n\tcat /sys/kernel/debug/kmemleak\n\nThe leaked memory is allocated in the stack below:\n\n do_syscall_64\n do_sys_open\n do_dentry_open\n full_proxy_open\n seq_open ---> alloc seq_file\n vfs_read\n full_proxy_read\n seq_read\n seq_read_iter\n traverse ---> alloc seq_buf\n\nAnd it should have been released in the following process:\n\n do_syscall_64\n syscall_exit_to_user_mode\n exit_to_user_mode_prepare\n task_work_run\n ____fput\n __fput\n full_proxy_release ---> free here\n\nHowever, the release function corresponding to file_operations is not\nimplemented in kfence. As a result, a memory leak occurs. Therefore,\nthe solution to this problem is to implement the corresponding release\nfunction."}, {"lang": "es", "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: kfence: repara la p\u00e9rdida de memoria cuando los objetos cat kfence Hulk robot inform\u00f3 un problema kmemleak: objeto sin referencia 0xffff93d1d8cc02e8 (tama\u00f1o 248): comm \"cat\", pid 23327, jiffies 4624670141 (edad 495992.217s ) volcado hexadecimal (primeros 32 bytes): 00 40 85 19 d4 93 ff ff 00 10 00 00 00 00 00 00 .@.............. 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................. rastreo inverso: seq_open+0x2a/0x80 full_proxy_open+0x167/0x1e0 do_dentry_open+0x1e1/0x3a0 path_openat+0x961/0xa20 do_filp_open+0xae/0x120 do_sys_openat2+0x216/0x2f0 do_sys_open+0x57/0x80 do_syscall_64+0x33/0x40 Entry_SYSCALL_64_after_hwframe+0x44/0xa9 objeto sin referencia 0xffff93d419854000 (tama\u00f1o 4096): comm \"cat\", pid 23327, Jiffies 4624670141 (edad 495992,217 s) volcado hexadecimal (primeros 32 bytes) : 6b 66 65 6e 63 65 2d 23 32 35 30 3a 20 30 78 30 kfence-#250: 0x0 30 30 30 30 30 30 30 37 35 34 62 64 61 31 32 2d 0000000754bda1 2- rastreo inverso: seq_read_iter+0x313/0x440 seq_read+ 0x14b/0x1a0 full_proxy_read+0x56/0x80 vfs_read+0xa5/0x1b0 ksys_read+0xa0/0xf0 do_syscall_64+0x33/0x40 Entry_SYSCALL_64_after_hwframe+0x44/0xa9 Creo que podemos reproducir f\u00e1cilmente este problema con los siguientes comandos: cat /sys/kernel/ depurar/ kfence/objects echo scan > /sys/kernel/debug/kmemleak cat /sys/kernel/debug/kmemleak La memoria filtrada se asigna en la pila siguiente: do_syscall_64 do_sys_open do_dentry_open full_proxy_open seq_open ---> alloc seq_file vfs_read full_proxy_read seq_read seq_read_iter traverse - --> alloc seq_buf Y deber\u00eda haberse liberado en el siguiente proceso: do_syscall_64 syscall_exit_to_user_mode exit_to_user_mode_prepare task_work_run ____fput __fput full_proxy_release ---> free aqu\u00ed Sin embargo, la funci\u00f3n de liberaci\u00f3n correspondiente a file_operatives no est\u00e1 implementada en kfence. Como resultado, se produce una p\u00e9rdida de memoria. Por tanto, la soluci\u00f3n a este problema es implementar la funci\u00f3n de liberaci\u00f3n correspondiente."}], "id": "CVE-2021-47089", "lastModified": "2026-06-17T04:16:26.517", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "LOW", "baseScore": 3.3, "baseSeverity": "LOW", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 1.4, "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2021-47089", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "total"}], "role": "CISA Coordinator", "timestamp": "2024-10-31T13:23:25.318113Z", "version": "2.0.3"}}]}, "published": "2024-03-04T18:15:07.560", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/0129ab1f268b6cf88825eae819b9b84aa0a85634"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/2f06c8293d27f6337f907042c602c9c953988c48"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/0129ab1f268b6cf88825eae819b9b84aa0a85634"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/2f06c8293d27f6337f907042c602c9c953988c48"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-401"}], "source": "nvd@nist.gov", "type": "Primary"}]}

{"bugzilla": {"description": "kernel: kfence: fix memory leak when cat kfence objects", "id": "2267936", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2267936"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.1", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H", "status": "draft"}, "cwe": "CWE-402", "details": ["In the Linux kernel, the following vulnerability has been resolved:\nkfence: fix memory leak when cat kfence objects\nHulk robot reported a kmemleak problem:\nunreferenced object 0xffff93d1d8cc02e8 (size 248):\ncomm \"cat\", pid 23327, jiffies 4624670141 (age 495992.217s)\nhex dump (first 32 bytes):\n00 40 85 19 d4 93 ff ff 00 10 00 00 00 00 00 00 .@..............\n00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................\nbacktrace:\nseq_open+0x2a/0x80\nfull_proxy_open+0x167/0x1e0\ndo_dentry_open+0x1e1/0x3a0\npath_openat+0x961/0xa20\ndo_filp_open+0xae/0x120\ndo_sys_openat2+0x216/0x2f0\ndo_sys_open+0x57/0x80\ndo_syscall_64+0x33/0x40\nentry_SYSCALL_64_after_hwframe+0x44/0xa9\nunreferenced object 0xffff93d419854000 (size 4096):\ncomm \"cat\", pid 23327, jiffies 4624670141 (age 495992.217s)\nhex dump (first 32 bytes):\n6b 66 65 6e 63 65 2d 23 32 35 30 3a 20 30 78 30 kfence-#250: 0x0\n30 30 30 30 30 30 30 37 35 34 62 64 61 31 32 2d 0000000754bda12-\nbacktrace:\nseq_read_iter+0x313/0x440\nseq_read+0x14b/0x1a0\nfull_proxy_read+0x56/0x80\nvfs_read+0xa5/0x1b0\nksys_read+0xa0/0xf0\ndo_syscall_64+0x33/0x40\nentry_SYSCALL_64_after_hwframe+0x44/0xa9\nI find that we can easily reproduce this problem with the following\ncommands:\ncat /sys/kernel/debug/kfence/objects\necho scan > /sys/kernel/debug/kmemleak\ncat /sys/kernel/debug/kmemleak\nThe leaked memory is allocated in the stack below:\ndo_syscall_64\ndo_sys_open\ndo_dentry_open\nfull_proxy_open\nseq_open ---> alloc seq_file\nvfs_read\nfull_proxy_read\nseq_read\nseq_read_iter\ntraverse ---> alloc seq_buf\nAnd it should have been released in the following process:\ndo_syscall_64\nsyscall_exit_to_user_mode\nexit_to_user_mode_prepare\ntask_work_run\n____fput\n__fput\nfull_proxy_release ---> free here\nHowever, the release function corresponding to file_operations is not\nimplemented in kfence. As a result, a memory leak occurs. Therefore,\nthe solution to this problem is to implement the corresponding release\nfunction."], "name": "CVE-2021-47089", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2024-03-04T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2021-47089\nhttps://nvd.nist.gov/vuln/detail/CVE-2021-47089\nhttps://lore.kernel.org/linux-cve-announce/2024030413-CVE-2021-47089-bc5a@gregkh/T"], "threat_severity": "Low"}

{}