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vuln-cve/data/2026/90xxx/CVE-2026-90177.json
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{
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"cveMetadata": {
"cveId": "CVE-2026-90177",
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"state": "PUBLISHED",
"assignerShortName": "Linux",
"dateReserved": "2026-09-11T19:38:34.791Z",
"datePublished": "2026-09-17T16:07:03.097Z",
"dateUpdated": "2026-10-21T12:50:19.113Z"
},
"containers": {
"cna": {
"providerMetadata": {
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux",
"dateUpdated": "2026-10-21T12:50:19.113Z"
},
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Check pointer type for all atomic RMW paths\n\nAtomic RMW verification records an instruction pointer type only when the\ncurrent destination is PTR_TO_ARENA. A second path can therefore reach the\nsame instruction with an ordinary pointer without comparing it against the\nsaved arena type.\n\nThe post-verification fixup uses the saved type to rewrite the instruction\nto BPF_PROBE_ATOMIC for every path. Record the actual destination type for\nall atomic RMW paths so the existing mismatch check rejects incompatible\nuses of one instruction."
}
],
"metrics": [
{
"cvssV3_1": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"baseScore": 7.8,
"baseSeverity": "HIGH"
},
"scenarios": [
{
"lang": "en",
"value": "AV:L - The attacker-controlled input is the BPF instruction stream copied in bpf_prog_load() from bpf(2) BPF_PROG_LOAD (__sys_bpf). do_check_insn() then check_atomic() then check_atomic_rmw() sees a mixed PTR_TO_ARENA versus kernel-pointer atomic; that bytecode is local syscall input, not a remote protocol payload.\nAC:L - The attacker authors both verifier paths: one branch with a PTR_TO_ARENA destination and another with PTR_TO_MAP_VALUE or PTR_TO_STACK at the same BPF_ATOMIC RMW. check_atomic_rmw() records only the arena type, bpf_convert_ctx_accesses() rewrites it to BPF_PROBE_ATOMIC, and bpf_prog_test_run_syscall() takes the non-arena path on demand.\nPR:L - The mixed path needs a BPF_MAP_TYPE_ARENA map; check_map_prog_compatibility() rejects that unless env->bpf_capable and env->allow_ptr_leaks (bpf_token_capable(CAP_BPF) and bpf_token_capable(CAP_PERFMON)). bpf_token_capable() uses ns_capable() on a delegated token userns, so this is not init-namespace root.\nUI:N - The attacker creates the arena with BPF_MAP_CREATE, loads the mixed-path program with BPF_PROG_LOAD, and executes it via bpf_prog_test_run() to bpf_prog_test_run_syscall(); no other user must mount, open a file, or otherwise cooperate.\nS:U - The confused BPF_PROBE_ATOMIC is JITed as emit_atomic_rmw_index() adding arena kern_vm_start (R12) onto a kernel map or stack pointer and runs in the host kernel; that is host memory corruption, not a KVM/Xen guest-to-host escape or IOMMU bypass.\nC:H - After bpf_convert_ctx_accesses() rewrites the shared RMW to BPF_PROBE_ATOMIC, the non-arena path executes lock xchg/cmpxchg/fetch-add at (PTR_TO_MAP_VALUE or PTR_TO_STACK + bpf_arena_get_kern_vm_start()). BPF_FETCH, XCHG, and CMPXCHG return the old value from that address, an arbitrary kernel read.\nI:H - The same instruction performs an attacker-chosen atomic RMW (BPF_ADD/AND/OR/XOR/XCHG/CMPXCHG in check_atomic_rmw) at kernel_ptr+kern_vm_start. With CONFIG_VMAP_STACK or a vmalloc map, that sum is a canonical direct-map address, giving a kernel write primitive.\nA:H - An atomic RMW into the direct map corrupts live kernel state and can panic; a non-canonical or unmapped sum that a JIT does not cover with an exception table oopses. Type-confused kernel atomics are Availability High."
}
]
}
],
"affected": [
{
"product": "Linux",
"vendor": "Linux",
"defaultStatus": "unaffected",
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"programFiles": [
"kernel/bpf/verifier.c"
],
"versions": [
{
"version": "d503a04f8bc0c75dc9db9452d8cc79d748afb752",
"lessThan": "b14dabe9656c1029abf3aa01e69c0d62f37f2f88",
"status": "affected",
"versionType": "git"
},
{
"version": "d503a04f8bc0c75dc9db9452d8cc79d748afb752",
"lessThan": "d4ba9d888ac0a8f12c78071fff73e1205a0b9293",
"status": "affected",
"versionType": "git"
},
{
"version": "d503a04f8bc0c75dc9db9452d8cc79d748afb752",
"lessThan": "eb287c6e81dedef92da01eb947f380d0aae513c3",
"status": "affected",
"versionType": "git"
},
{
"version": "d503a04f8bc0c75dc9db9452d8cc79d748afb752",
"lessThan": "4bc49ae344d65cfcef738f281ac575cf73ca2fc5",
"status": "affected",
"versionType": "git"
}
]
},
{
"product": "Linux",
"vendor": "Linux",
"defaultStatus": "affected",
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"programFiles": [
"kernel/bpf/verifier.c"
],
"versions": [
{
"version": "6.10",
"status": "affected"
},
{
"version": "0",
"lessThan": "6.10",
"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": "6.10",
"versionEndExcluding": "6.12.114"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "6.10",
"versionEndExcluding": "6.18.57"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "6.10",
"versionEndExcluding": "7.2.6"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "6.10",
"versionEndExcluding": "7.3"
}
]
}
]
}
],
"references": [
{
"url": "https://git.kernel.org/stable/c/b14dabe9656c1029abf3aa01e69c0d62f37f2f88"
},
{
"url": "https://git.kernel.org/stable/c/d4ba9d888ac0a8f12c78071fff73e1205a0b9293"
},
{
"url": "https://git.kernel.org/stable/c/eb287c6e81dedef92da01eb947f380d0aae513c3"
},
{
"url": "https://git.kernel.org/stable/c/4bc49ae344d65cfcef738f281ac575cf73ca2fc5"
}
],
"title": "bpf: Check pointer type for all atomic RMW paths",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
}
}