CVE-2022-49977

{"id": "CVE-2022-49977", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 5.5, "attackVector": "LOCAL", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 1.8}]}, "published": "2025-06-18T11:15:25.120", "references": [{"url": "https://git.kernel.org/stable/c/4c34a2a6c9927c239dd2e295a03d49b37b618d2c", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/8569b4ada1e0b9bfaa125bd0c0967918b6560fa2", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/934e49f7d696afdae9f979abe3f308408184e17b", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/c3b0f72e805f0801f05fa2aa52011c4bfc694c44", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/d81bd6671f45fde4c3ac7fd7733c6e3082ae9d8e", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/dbd8c8fc60480e3faa3ae7e27ebe03371ecd1b77", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/ddffe882d74ef43a3494f0ab0c24baf076c45f96", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/e4ae97295984ff1b9b340ed18ae1b066f36b7835", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Primary", "source": "nvd@nist.gov", "description": [{"lang": "en", "value": "CWE-476"}]}], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nftrace: Fix NULL pointer dereference in is_ftrace_trampoline when ftrace is dead\n\nftrace_startup does not remove ops from ftrace_ops_list when\nftrace_startup_enable fails:\n\nregister_ftrace_function\n ftrace_startup\n __register_ftrace_function\n ...\n add_ftrace_ops(&ftrace_ops_list, ops)\n ...\n ...\n ftrace_startup_enable // if ftrace failed to modify, ftrace_disabled is set to 1\n ...\n return 0 // ops is in the ftrace_ops_list.\n\nWhen ftrace_disabled = 1, unregister_ftrace_function simply returns without doing anything:\nunregister_ftrace_function\n ftrace_shutdown\n if (unlikely(ftrace_disabled))\n return -ENODEV; // return here, __unregister_ftrace_function is not executed,\n // as a result, ops is still in the ftrace_ops_list\n __unregister_ftrace_function\n ...\n\nIf ops is dynamically allocated, it will be free later, in this case,\nis_ftrace_trampoline accesses NULL pointer:\n\nis_ftrace_trampoline\n ftrace_ops_trampoline\n do_for_each_ftrace_op(op, ftrace_ops_list) // OOPS! op may be NULL!\n\nSyzkaller reports as follows:\n[ 1203.506103] BUG: kernel NULL pointer dereference, address: 000000000000010b\n[ 1203.508039] #PF: supervisor read access in kernel mode\n[ 1203.508798] #PF: error_code(0x0000) - not-present page\n[ 1203.509558] PGD 800000011660b067 P4D 800000011660b067 PUD 130fb8067 PMD 0\n[ 1203.510560] Oops: 0000 [#1] SMP KASAN PTI\n[ 1203.511189] CPU: 6 PID: 29532 Comm: syz-executor.2 Tainted: G B W 5.10.0 #8\n[ 1203.512324] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014\n[ 1203.513895] RIP: 0010:is_ftrace_trampoline+0x26/0xb0\n[ 1203.514644] Code: ff eb d3 90 41 55 41 54 49 89 fc 55 53 e8 f2 00 fd ff 48 8b 1d 3b 35 5d 03 e8 e6 00 fd ff 48 8d bb 90 00 00 00 e8 2a 81 26 00 <48> 8b ab 90 00 00 00 48 85 ed 74 1d e8 c9 00 fd ff 48 8d bb 98 00\n[ 1203.518838] RSP: 0018:ffffc900012cf960 EFLAGS: 00010246\n[ 1203.520092] RAX: 0000000000000000 RBX: 000000000000007b RCX: ffffffff8a331866\n[ 1203.521469] RDX: 0000000000000000 RSI: 0000000000000008 RDI: 000000000000010b\n[ 1203.522583] RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8df18b07\n[ 1203.523550] R10: fffffbfff1be3160 R11: 0000000000000001 R12: 0000000000478399\n[ 1203.524596] R13: 0000000000000000 R14: ffff888145088000 R15: 0000000000000008\n[ 1203.525634] FS: 00007f429f5f4700(0000) GS:ffff8881daf00000(0000) knlGS:0000000000000000\n[ 1203.526801] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n[ 1203.527626] CR2: 000000000000010b CR3: 0000000170e1e001 CR4: 00000000003706e0\n[ 1203.528611] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000\n[ 1203.529605] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400\n\nTherefore, when ftrace_startup_enable fails, we need to rollback registration\nprocess and remove ops from ftrace_ops_list."}, {"lang": "es", "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: ftrace: Se corrige la desreferencia del puntero NULL en is_ftrace_trampoline cuando ftrace est\u00e1 inactivo ftrace_startup no elimina las operaciones de ftrace_ops_list cuando ftrace_startup_enable falla: register_ftrace_function ftrace_startup __register_ftrace_function ... add_ftrace_ops(&amp;ftrace_ops_list, ops) ... ... ftrace_startup_enable // si ftrace no se modific\u00f3, ftrace_disabled se establece en 1 ... return 0 // las operaciones est\u00e1n en ftrace_ops_list. Cuando ftrace_disabled = 1, unregister_ftrace_function simplemente regresa sin hacer nada: unregister_ftrace_function ftrace_shutdown if (unlikely(ftrace_disabled)) return -ENODEV; // regresa aqu\u00ed, __unregister_ftrace_function no se ejecuta, // como resultado, ops todav\u00eda est\u00e1 en ftrace_ops_list __unregister_ftrace_function ... Si ops se asigna din\u00e1micamente, estar\u00e1 libre m\u00e1s tarde, en este caso, is_ftrace_trampoline accede al puntero NULL: is_ftrace_trampoline ftrace_ops_trampoline do_for_each_ftrace_op(op, ftrace_ops_list) // \u00a1UPS! \u00a1op puede ser NULL! Syzkaller informa lo siguiente: [ 1203.506103] ERROR: desreferencia de puntero NULL del kernel, direcci\u00f3n: 000000000000010b [ 1203.508039] #PF: acceso de lectura del supervisor en modo kernel [ 1203.508798] #PF: error_code(0x0000) - p\u00e1gina no presente [ 1203.509558] PGD 800000011660b067 P4D 800000011660b067 PUD 130fb8067 PMD 0 [ 1203.510560] Oops: 0000 [#1] SMP KASAN PTI [ 1203.511189] CPU: 6 PID: 29532 Comm: syz-executor.2 Contaminado: GBW 5.10.0 #8 [1203.512324] Nombre del hardware: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 01/04/2014 [1203.513895] RIP: 0010:is_ftrace_trampoline+0x26/0xb0 [1203.514644] C\u00f3digo: ff eb d3 90 41 55 41 54 49 89 fc 55 53 e8 f2 00 fd ff 48 8b 1d 3b 35 5d 03 e8 e6 00 fd ff 48 8d bb 90 00 00 00 e8 2a 81 26 00 &lt;48&gt; 8b ab 90 00 00 00 48 85 ed 74 1d e8 c9 00 fd ff 48 8d bb 98 00 [ 1203.518838] RSP: 0018:ffffc900012cf960 EFLAGS: 00010246 [ 1203.520092] RAX: 000000000000000 RBX: 000000000000007b RCX: ffffffff8a331866 [ 1203.521469] RDX: 00000000000000000 RSI: 0000000000000008 RDI: 0000000000000010b [ 1203.522583] RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8df18b07 [ 1203.523550] R10: fffffbfff1be3160 R11: 000000000000001 R12: 0000000000478399 [ 1203.524596] R13: 000000000000000 R14: ffff888145088000 R15: 0000000000000008 [ 1203.525634] FS: 00007f429f5f4700(0000) GS:ffff8881daf00000(0000) knlGS:0000000000000000 [ 1203.526801] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 1203.527626] CR2: 00000000000010b CR3: 0000000170e1e001 CR4: 000000000003706e0 [ 1203.528611] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 1203.529605] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Por lo tanto, cuando ftrace_startup_enable falla, debemos revertir el proceso de registro y eliminar las operaciones de ftrace_ops_list."}], "lastModified": "2025-11-14T18:16:19.487", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "3433BB10-41AC-4CF0-B19A-0EC09FF26272", "versionEndExcluding": "4.9.327"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "42DF7D19-F259-47AF-8715-288480443B27", "versionEndExcluding": "4.14.292", "versionStartIncluding": "4.10"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "379F570B-8101-4252-AE1C-B802D441D9B4", "versionEndExcluding": "4.19.257", "versionStartIncluding": "4.15"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "BEFFBCD7-9B53-46AB-B3FD-53EAD80FD3E1", "versionEndExcluding": "5.4.212", "versionStartIncluding": "4.20"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "6872143E-BF6D-4DB5-8454-D843F608AB3B", "versionEndExcluding": "5.10.141", "versionStartIncluding": "5.5"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "81162A58-341F-455C-96D5-6DF30A0F9295", "versionEndExcluding": "5.15.65", "versionStartIncluding": "5.11"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "DEBCC9D9-2058-44E1-8A2E-ABC880E4DE50", "versionEndExcluding": "5.19.7", "versionStartIncluding": "5.16"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.0:rc1:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "E8BD11A3-8643-49B6-BADE-5029A0117325"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}