{ "schema_version": "1.6.1", "id": "RPI-CVE-2026-90269", "modified": "2026-10-07T14:35:31Z", "upstream": [ "CVE-2026-90269" ], "published": "2026-09-17T16:10:40Z", "summary": "bpf: Reject load-acquire from pointers requiring fault protection", "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Reject load-acquire from pointers requiring fault protection\n\nA BPF_LOAD_ACQ is not rewritten to a BPF_PROBE_MEM load by the verifier,\nunlike a regular BPF_LDX, so the JIT emits a plain load with no exception\ntable entry and a fault panics the kernel instead of being handled.\n\nReject the source pointer types that a BPF_LDX would have had that fault\nprotection applied to, i.e. the ones bpf_convert_ctx_accesses() turns\ninto BPF_PROBE_MEM: a bare PTR_TO_BTF_ID, PTR_TO_BTF_ID | PTR_UNTRUSTED,\nPTR_TO_BTF_ID | MEM_ALLOC | PTR_UNTRUSTED and PTR_TO_MEM | MEM_RDONLY |\nPTR_UNTRUSTED.\n\nThis is reachable e.g. by loading ->mm out of a trusted task_struct\nyields an untrusted pointer to mm_struct, and it is NULL for a kernel\nthread:\n\n [...]\n SEC(\"tp_btf/sched_switch\")\n int BPF_PROG(demo, bool preempt, struct task_struct *prev,\n struct task_struct *next)\n {\n struct mm_struct *mm = next->mm; /* untrusted */\n\n out_ldx = (__u64)mm->pgd; /* BPF_LDX */\n out_acq = load_acquire(&mm->pgd); /* BPF_LOAD_ACQ */\n return 0;\n }\n [...]\n\nBoth dereference the same pointer, but only the BPF_LDX is protected\n(x86-64 JIT, jump targets shown prog-relative):\n\n [...]\n ; out_ldx = (__u64)mm->pgd;\n 17: movq $-10485760, %r10\n 1e: movq %rsi, %r11\n 21: addq $184, %r11\n 28: subq %r10, %r11\n 2b: movabsq $140737498841088, %r10\n 35: cmpq %r10, %r11\n 38: ja 0x3e <-- kernel addr?\n 3a: xorl %edi, %edi <-- no: dst = 0, skip the load\n 3c: jmp 0x45\n 3e: movq 184(%rsi), %rdi <-- yes: load + extable entry\n [...]\n ; load_acquire(&mm->pgd)\n 53:\tmovq %rsi, %rdi\n 56:\tmovq 184(%rdi), %rax <-- no check, no extable entry\n [...]\n\nNote that BPF_PROBE_MEM is not visible in a bpftool xlated dump, as\nbpf_insn_prepare_dump() rewrites it back to BPF_MEM.\n\nA PTR_TRUSTED pointer is deliberately not on the list. Such a load is\nnot converted either, but it does not need to be, since the pointer is\nguaranteed live, so load-acquire from it stays allowed.\n\nThe check is gated on BPF_LOAD_ACQ so that atomic RMW and store-release\nerror messages are unchanged; writes (RMW / store-release) to such\npointers are already rejected elsewhere, so only load-acquire needs this.", "affected": [ { "package": { "ecosystem": "Raspberry Pi OS:13", "name": "linux" }, "versions": [ "1:6.18.29-1+rpt1", "1:6.18.33-1+rpt1", "1:6.18.34-1+rpt1", "1:6.18.39-1+rpt1", "1:6.18.50-1+rpt1" ], "ecosystem_specific": { "binaries": [ { "binary_name": "linux-image-6.18.29+rpt-rpi-2712", "binary_version": "1:6.18.29-1+rpt1" }, { "binary_name": "linux-image-6.18.29+rpt-rpi-v6", "binary_version": "1:6.18.29-1+rpt1" }, { "binary_name": "linux-image-6.18.29+rpt-rpi-v7", "binary_version": "1:6.18.29-1+rpt1" }, { "binary_name": "linux-image-6.18.29+rpt-rpi-v8", "binary_version": "1:6.18.29-1+rpt1" }, { "binary_name": "linux-image-6.18.29+rpt-rpi-v8-rt", "binary_version": "1:6.18.29-1+rpt1" }, { "binary_name": "linux-image-6.18.33+rpt-rpi-2712", "binary_version": "1:6.18.33-1+rpt1" }, { "binary_name": "linux-image-6.18.33+rpt-rpi-v6", "binary_version": "1:6.18.33-1+rpt1" }, { "binary_name": "linux-image-6.18.33+rpt-rpi-v7", "binary_version": "1:6.18.33-1+rpt1" }, { "binary_name": "linux-image-6.18.33+rpt-rpi-v8", "binary_version": "1:6.18.33-1+rpt1" }, { "binary_name": "linux-image-6.18.33+rpt-rpi-v8-rt", "binary_version": "1:6.18.33-1+rpt1" }, { "binary_name": "linux-image-6.18.34+rpt-rpi-2712", "binary_version": "1:6.18.34-1+rpt1" }, { "binary_name": "linux-image-6.18.34+rpt-rpi-v6", "binary_version": "1:6.18.34-1+rpt1" }, { "binary_name": "linux-image-6.18.34+rpt-rpi-v7", "binary_version": "1:6.18.34-1+rpt1" }, { "binary_name": "linux-image-6.18.34+rpt-rpi-v8", "binary_version": "1:6.18.34-1+rpt1" }, { "binary_name": "linux-image-6.18.34+rpt-rpi-v8-rt", "binary_version": "1:6.18.34-1+rpt1" }, { "binary_name": "linux-image-6.18.39+rpt-rpi-2712", "binary_version": "1:6.18.39-1+rpt1" }, { "binary_name": "linux-image-6.18.39+rpt-rpi-v6", "binary_version": "1:6.18.39-1+rpt1" }, { "binary_name": "linux-image-6.18.39+rpt-rpi-v7", "binary_version": "1:6.18.39-1+rpt1" }, { "binary_name": "linux-image-6.18.39+rpt-rpi-v8", "binary_version": "1:6.18.39-1+rpt1" }, { "binary_name": "linux-image-6.18.39+rpt-rpi-v8-rt", "binary_version": "1:6.18.39-1+rpt1" }, { "binary_name": "linux-image-6.18.50+rpt-rpi-2712", "binary_version": "1:6.18.50-1+rpt1" }, { "binary_name": "linux-image-6.18.50+rpt-rpi-v6", "binary_version": "1:6.18.50-1+rpt1" }, { "binary_name": "linux-image-6.18.50+rpt-rpi-v7", "binary_version": "1:6.18.50-1+rpt1" }, { "binary_name": "linux-image-6.18.50+rpt-rpi-v8", "binary_version": "1:6.18.50-1+rpt1" }, { "binary_name": "linux-image-6.18.50+rpt-rpi-v8-rt", "binary_version": "1:6.18.50-1+rpt1" } ] }, "database_specific": { "per_version": { "1:6.18.29-1+rpt1": { "linux_commit": "66318c5b5cd8145a662303af12ed39ac07eb27cc", "upstream_version": "6.18.29", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.18.52" }, "1:6.18.33-1+rpt1": { "linux_commit": "95b85bebbedcaedfa7ca79116ed38b7376fba412", "upstream_version": "6.18.33", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.18.52" }, "1:6.18.34-1+rpt1": { "linux_commit": "c8c7494100e99ee05b11aaa4f0588a223a63d1af", "upstream_version": "6.18.34", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.18.52" }, "1:6.18.39-1+rpt1": { "linux_commit": "60ea684a8ace97bb0db1a16e20753bdd6ab371ff", "upstream_version": "6.18.39", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.18.52" }, "1:6.18.50-1+rpt1": { "linux_commit": "cff533aec2fa601846766b32ff57204e0a61bed7", "upstream_version": "6.18.50", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.18.52" } } } } ], "references": [ { "type": "ADVISORY", "url": "https://www.cve.org/CVERecord?id=CVE-2026-90269" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/c4c8de3bf48d3756ab0f910fe5cc4937d70efdcd" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/5f8ade6e9b7931fc9697394f1b2c4ae833f5ac18" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/7db0a00445f1a40bacfe9b747405c11cb5f10fc9" } ], "database_specific": { "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git", "upstream_modified": "2026-09-17T16:10:40Z" } }