{ "dataType": "CVE_RECORD", "cveMetadata": { "cveId": "CVE-2024-35871", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-05-17T13:50:33.108Z", "datePublished": "2024-05-19T08:34:29.292Z", "dateUpdated": "2024-08-02T03:21:49.064Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2024-05-29T05:30:27.722Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nriscv: process: Fix kernel gp leakage\n\nchildregs represents the registers which are active for the new thread\nin user context. For a kernel thread, childregs->gp is never used since\nthe kernel gp is not touched by switch_to. For a user mode helper, the\ngp value can be observed in user space after execve or possibly by other\nmeans.\n\n[From the email thread]\n\nThe /* Kernel thread */ comment is somewhat inaccurate in that it is also used\nfor user_mode_helper threads, which exec a user process, e.g. /sbin/init or\nwhen /proc/sys/kernel/core_pattern is a pipe. Such threads do not have\nPF_KTHREAD set and are valid targets for ptrace etc. even before they exec.\n\nchildregs is the *user* context during syscall execution and it is observable\nfrom userspace in at least five ways:\n\n1. kernel_execve does not currently clear integer registers, so the starting\n register state for PID 1 and other user processes started by the kernel has\n sp = user stack, gp = kernel __global_pointer$, all other integer registers\n zeroed by the memset in the patch comment.\n\n This is a bug in its own right, but I'm unwilling to bet that it is the only\n way to exploit the issue addressed by this patch.\n\n2. ptrace(PTRACE_GETREGSET): you can PTRACE_ATTACH to a user_mode_helper thread\n before it execs, but ptrace requires SIGSTOP to be delivered which can only\n happen at user/kernel boundaries.\n\n3. /proc/*/task/*/syscall: this is perfectly happy to read pt_regs for\n user_mode_helpers before the exec completes, but gp is not one of the\n registers it returns.\n\n4. PERF_SAMPLE_REGS_USER: LOCKDOWN_PERF normally prevents access to kernel\n addresses via PERF_SAMPLE_REGS_INTR, but due to this bug kernel addresses\n are also exposed via PERF_SAMPLE_REGS_USER which is permitted under\n LOCKDOWN_PERF. I have not attempted to write exploit code.\n\n5. Much of the tracing infrastructure allows access to user registers. I have\n not attempted to determine which forms of tracing allow access to user\n registers without already allowing access to kernel registers." } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "arch/riscv/kernel/process.c" ], "versions": [ { "version": "7db91e57a0ac", "lessThan": "9abc3e6f1116", "status": "affected", "versionType": "git" }, { "version": "7db91e57a0ac", "lessThan": "dff6072124f6", "status": "affected", "versionType": "git" }, { "version": "7db91e57a0ac", "lessThan": "f6583444d7e7", "status": "affected", "versionType": "git" }, { "version": "7db91e57a0ac", "lessThan": "00effef72c98", "status": "affected", "versionType": "git" }, { "version": "7db91e57a0ac", "lessThan": "d8dcba0691b8", "status": "affected", "versionType": "git" }, { "version": "7db91e57a0ac", "lessThan": "d14fa1fcf69d", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "arch/riscv/kernel/process.c" ], "versions": [ { "version": "4.15", "status": "affected" }, { "version": "0", "lessThan": "4.15", "status": "unaffected", "versionType": "custom" }, { "version": "5.10.216", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "custom" }, { "version": "5.15.154", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "custom" }, { "version": "6.1.85", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "custom" }, { "version": "6.6.26", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "custom" }, { "version": "6.8.5", "lessThanOrEqual": "6.8.*", "status": "unaffected", "versionType": "custom" }, { "version": "6.9", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/9abc3e6f1116adb7a2d4fbb8ce20c37916976bf5" }, { "url": "https://git.kernel.org/stable/c/dff6072124f6df77bfd36951fbd88565746980ef" }, { "url": "https://git.kernel.org/stable/c/f6583444d7e78dae750798552b65a2519ff3ca84" }, { "url": "https://git.kernel.org/stable/c/00effef72c98294edb1efa87ffa0f6cfb61b36a4" }, { "url": "https://git.kernel.org/stable/c/d8dcba0691b8e42bddb61aab201e4d918a08e5d9" }, { "url": "https://git.kernel.org/stable/c/d14fa1fcf69db9d070e75f1c4425211fa619dfc8" }, { "url": "https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html" } ], "title": "riscv: process: Fix kernel gp leakage", "x_generator": { "engine": "bippy-a5840b7849dd" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "timestamp": "2024-06-17T17:38:51.778237Z", "id": "CVE-2024-35871", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "partial" } ], "role": "CISA Coordinator", "version": "2.0.3" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-06-17T17:41:55.174Z" } }, { "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2024-08-02T03:21:49.064Z" }, "title": "CVE Program Container", "references": [ { "url": "https://git.kernel.org/stable/c/9abc3e6f1116adb7a2d4fbb8ce20c37916976bf5", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/dff6072124f6df77bfd36951fbd88565746980ef", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/f6583444d7e78dae750798552b65a2519ff3ca84", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/00effef72c98294edb1efa87ffa0f6cfb61b36a4", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/d8dcba0691b8e42bddb61aab201e4d918a08e5d9", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/d14fa1fcf69db9d070e75f1c4425211fa619dfc8", "tags": [ "x_transferred" ] }, { "url": "https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html", "tags": [ "x_transferred" ] } ] } ] }, "dataVersion": "5.1" }