{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-90358", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.806Z", "datePublished": "2026-09-17T16:09:03.531Z", "dateUpdated": "2026-10-19T09:02:14.615Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T09:02:14.615Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf, x86: Fix trampoline stack size for 128-bit arguments\n\nbtf_distill_func_proto() accepts a function argument up to 16 bytes, so a\n128-bit scalar such as __int128 reaches the x86 trampoline with\narg_size == 16. But the current implementation assumes an __int128\nargument only needs one register, so the register save area is\nunder-allocated and save_args() overwrites adjacent stack slots.\n\nCompute the register count from arg_size for all arguments to fix it." } ], "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 under-allocation is in __arch_prepare_bpf_trampoline()/save_args() in arch/x86/net/bpf_jit_comp.c and is reached only when a local process issues bpf(BPF_PROG_LOAD) for BPF_PROG_TYPE_TRACING fentry/fexit and bpf(BPF_LINK_CREATE) against a BTF function with a 16-byte integer argument. BPF is a local syscall vector, not a network protocol parser.\nAC:L - The attacker selects an attach target whose BTF has arg_size==16 without BTF_FMODEL_STRUCT_ARG (e.g. bpf_testmod_test_int128_arg). __arch_prepare_bpf_trampoline() then under-counts nr_regs by one slot per such argument and save_args() deterministically overwrites the next stack slot; no race or uninfluenced layout is required.\nPR:L - bpf_prog_load() rejects BPF_PROG_TYPE_TRACING unless bpf_token_capable(CAP_BPF) and, via is_perfmon_prog_type(), bpf_token_capable(CAP_PERFMON). Those capabilities are delegable with BPF tokens and are scored Low, not init-namespace root, consistent with other BPF trampoline CVEs.\nUI:N - The attacker loads the fentry/fexit program, attaches it with BPF_LINK_CREATE, and invokes the target themselves (for bpf_testmod, a read of the module sysfs test file that calls bpf_testmod_test_int128_arg). No separate victim mount or click is required.\nS:U - save_args() overwrites the trampoline's own saved RBP and adjacent slots in the host kernel stack. That is in-kernel memory corruption on the same authority, not a KVM/Xen guest-to-host, IOMMU, or sandbox boundary crossing.\nC:H - The extra 8-byte store of the __int128's second register (RSI) lands in adjacent trampoline slots. On an fentry trampoline without a return-value slot that is saved RBP, so leave pivots RSP through argument contents and subsequent pops/unwinds can disclose kernel stack/memory.\nI:H - The same OOB store overwrites saved RBP (and with two 16-byte scalars, the return address at RBP+8). The trampoline epilogue then executes leave; ret on a corrupted frame, which is kernel stack memory corruption exploitable for a stack pivot and control-flow hijack.\nA:H - Overwriting saved RBP with the high half of a small __int128 (0 for bpf_testmod_test_int128_arg((__int128)1,...)) makes leave load a bogus frame pointer, so the following pop/ret oopses or panics the kernel." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "arch/x86/net/bpf_jit_comp.c" ], "versions": [ { "version": "a9c5ad31fbdc4dec6d266fe22e51de1ad6d1bcf2", "lessThan": "4aed2346fa9b88d458eeb8c01123f3c07585a675", "status": "affected", "versionType": "git" }, { "version": "a9c5ad31fbdc4dec6d266fe22e51de1ad6d1bcf2", "lessThan": "40f3bfbbb222b92278f3797614b70f68d46824ac", "status": "affected", "versionType": "git" }, { "version": "a9c5ad31fbdc4dec6d266fe22e51de1ad6d1bcf2", "lessThan": "a6d7d7a253c550e74b0651897fe313c2f9b2301f", "status": "affected", "versionType": "git" }, { "version": "a9c5ad31fbdc4dec6d266fe22e51de1ad6d1bcf2", "lessThan": "814cba835ef648e0c5eb79505c96c0493b29eea6", "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/x86/net/bpf_jit_comp.c" ], "versions": [ { "version": "6.1", "status": "affected" }, { "version": "0", "lessThan": "6.1", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.110", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.52", "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": "6.1", "versionEndExcluding": "6.12.110" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.1", "versionEndExcluding": "6.18.52" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.1", "versionEndExcluding": "7.2.6" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.1", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/4aed2346fa9b88d458eeb8c01123f3c07585a675" }, { "url": "https://git.kernel.org/stable/c/40f3bfbbb222b92278f3797614b70f68d46824ac" }, { "url": "https://git.kernel.org/stable/c/a6d7d7a253c550e74b0651897fe313c2f9b2301f" }, { "url": "https://git.kernel.org/stable/c/814cba835ef648e0c5eb79505c96c0493b29eea6" } ], "title": "bpf, x86: Fix trampoline stack size for 128-bit arguments", "x_generator": { "engine": "bippy-1.2.0" } } } }