{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-90347", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.805Z", "datePublished": "2026-09-17T16:08:56.232Z", "dateUpdated": "2026-10-21T12:51:12.725Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-21T12:51:12.725Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\narm64: ptrace: Keep 'orig_x0' in-sync with x0 on syscall entry\n\nCommit e057b9477232 (\"arm64: syscall: Ensure saved x0 is kept in-sync\nwith tracer updates\") attempted to resolve a long-standing issue with\nsyscall entry tracing, where a tracer is able to manipulate the first\nsyscall argument without being subjected to seccomp or audit checking.\n\nUnfortunately, that fix was incomplete [1], as it failed to update\n'orig_x0' between a tracer updating x0 during a seccomp ptrace exit\n(SECCOMP_RET_TRACE) and the seccomp filter being re-evaluated.\n\nRather than add hooks to the core seccomp code, instead move the\nsynchronisation code into the ptrace GPR and syscall setting code so\nthat 'orig_x0' is kept up to date with x0 whenever we're stopped on the\nsyscall entry path." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N", "baseScore": 8.4, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The attacker-controlled value is x0 written by ptrace(PTRACE_SETREGSET, NT_PRSTATUS) into gpr_set() while the tracee is stopped in syscall_trace_enter() after ptrace_report_syscall_entry() or ptrace_event(PTRACE_EVENT_SECCOMP) from SECCOMP_RET_TRACE. That write is a local ptrace syscall, not a received protocol message.\nAC:L - The tracer owns the stop: waitpid() for the PTRACE_SYSCALL enter-stop or PTRACE_EVENT_SECCOMP trap, PTRACE_SETREGSET to replace regs[0], then PTRACE_CONT. el0_svc_common() then reaches secure_computing() with orig_x0 still equal to the pre-ptrace x0. No race or uninfluenced layout is required.\nPR:L - __ptrace_may_access() allows a same-uid tracer, and default yama ptrace_scope (YAMA_SCOPE_RELATIONAL) permits PTRACE_TRACEME or PTRACE_ATTACH to a descendant without CAP_SYS_PTRACE. An ordinary user can fork, trace the child, and issue PTRACE_SETREGSET; init-namespace root is not required.\nUI:N - The attacker issues PTRACE_TRACEME/PTRACE_SYSCALL, PTRACE_SETREGSET of NT_PRSTATUS, and the in-flight syscall on their own descendant. No separate victim action such as mounting a filesystem or opening a file is required.\nS:C - populate_seccomp_data() exposes orig_x0 as sd.args[0] to a parent-installed seccomp filter (container runtime, systemd RestrictNamespaces, Android minijail). gpr_set() updates regs[0] without orig_x0, so invoke_syscall() via SC_ARM64_REGS_TO_ARGS runs a denied first argument while the filter still allows the old orig_x0, escaping that sandbox.\nC:H - syscall_get_arguments() returns stale orig_x0 to seccomp while __arm64_sys_* wrappers take regs[0]. A tracer starts an allowed openat(dfd) or socket(domain) and replaces x0 with a blocked directory fd or AF_NETLINK/AF_PACKET, so the syscall discloses files or netlink state the filter was written to deny.\nI:H - arm64 clone() takes clone_flags in x0 (CONFIG_CLONE_BACKWARDS). After gpr_set() writes regs[0] without orig_x0, __seccomp_filter() (including the SECCOMP_RET_TRACE recheck) still sees the allowed flags while invoke_syscall() honors CLONE_NEWUSER/CLONE_NEWNS the policy forbade; substituting write/ioctl's fd in x0 likewise modifies data the filter blocked.\nA:N - The bug is orig_x0 remaining stale after gpr_set() so populate_seccomp_data() and audit_syscall_entry() inspect the wrong first argument. That is a seccomp/audit policy bypass, not memory corruption, and it does not oops, panic, deadlock, or hang the kernel." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "arch/arm64/kernel/ptrace.c" ], "versions": [ { "version": "a5cd110cb8369d6b37ef5ccfe56b3fa1338c9615", "lessThan": "332c9c1a148d0425326989c1187face8f6b2a60c", "status": "affected", "versionType": "git" }, { "version": "a5cd110cb8369d6b37ef5ccfe56b3fa1338c9615", "lessThan": "ce17c651a90e242ad48df0df89b1e4cebcda5e14", "status": "affected", "versionType": "git" }, { "version": "a5cd110cb8369d6b37ef5ccfe56b3fa1338c9615", "lessThan": "e9e2854fcff5733ffc607e8ecc87e0e591ab41fd", "status": "affected", "versionType": "git" }, { "version": "a5cd110cb8369d6b37ef5ccfe56b3fa1338c9615", "lessThan": "f433869f23841a50455c4087d85540d5b4d37cde", "status": "affected", "versionType": "git" }, { "version": "a5cd110cb8369d6b37ef5ccfe56b3fa1338c9615", "lessThan": "88b839ce497ccb1ff92f7ae742c78dd2937ba572", "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/arm64/kernel/ptrace.c" ], "versions": [ { "version": "4.8", "status": "affected" }, { "version": "0", "lessThan": "4.8", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.160", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.114", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.57", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.6", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.3", "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": "4.8", "versionEndExcluding": "6.6.160" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.8", "versionEndExcluding": "6.12.114" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.8", "versionEndExcluding": "6.18.57" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.8", "versionEndExcluding": "7.2.6" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.8", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/332c9c1a148d0425326989c1187face8f6b2a60c" }, { "url": "https://git.kernel.org/stable/c/ce17c651a90e242ad48df0df89b1e4cebcda5e14" }, { "url": "https://git.kernel.org/stable/c/e9e2854fcff5733ffc607e8ecc87e0e591ab41fd" }, { "url": "https://git.kernel.org/stable/c/f433869f23841a50455c4087d85540d5b4d37cde" }, { "url": "https://git.kernel.org/stable/c/88b839ce497ccb1ff92f7ae742c78dd2937ba572" } ], "title": "arm64: ptrace: Keep 'orig_x0' in-sync with x0 on syscall entry", "x_generator": { "engine": "bippy-1.2.0" } } } }