{"id":"CVE-2025-38591","revision":"f7f58de6e7d146c4880862b4766c4bd9","records":[{"revision":"f7f58de6e7d146c4880862b4766c4bd9","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2025-38591","aliases":[],"title":"bpf: Reject narrower access to pointer ctx fields","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Reject narrower access to pointer ctx fields\n\nThe following BPF program, simplified from a syzkaller repro, causes a\nkernel warning:\n\n    r0 = *(u8 *)(r1 + 169);\n    exit;\n\nWith pointer field sk being at offset 168 in __sk_buff. This access is\ndetected as a narrower read in bpf_skb_is_valid_access because it\ndoesn't match offsetof(struct __sk_buff, sk). It is therefore allowed\nand later proceeds to bpf_convert_ctx_access. Note that for the\n\"is_narrower_load\" case in the convert_ctx_accesses(), the insn->off\nis aligned, so the cnt may not be 0 because it matches the\noffsetof(struct __sk_buff, sk) in the bpf_convert_ctx_access. However,\nthe target_size stays 0 and the verifier errors with a kernel warning:\n\n    verifier bug: error during ctx access conversion(1)\n\nThis patch fixes that to return a proper \"invalid bpf_context access\noff=X size=Y\" error on the load instruction.\n\nThe same issue affects multiple other fields in context structures that\nallow narrow access. Some other non-affected fields (for sk_msg,\nsk_lookup, and sockopt) were also changed to use bpf_ctx_range_ptr for\nconsistency.\n\nNote this syzkaller crash was reported in the \"Closes\" link below, which\nused to be about a different bug, fixed in\ncommit fce7bd8e385a (\"bpf/verifier: Handle BPF_LOAD_ACQ instructions\nin insn_def_regno()\"). Because syzbot somehow confused the two bugs,\nthe new crash and repro didn't get reported to the mailing list.","state":0,"publishedAt":"2025-08-19T17:03:12.508+00:00","modifiedAt":"2026-10-15T01:07:31.83+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"kernel/bpf/cgroup.c\",\n                        \"net/core/filter.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"f96da09473b52c09125cc9bf7d7d4576ae8229e0\",\n                            \"lessThan\": \"7847c4140e06f6e87229faae22cc38525334c156\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"f96da09473b52c09125cc9bf7d7d4576ae8229e0\",\n                            \"lessThan\": \"feae34c992eb7191862fb1594c704fbbf650fef8\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"f96da09473b52c09125cc9bf7d7d4576ae8229e0\",\n                            \"lessThan\": \"33660d44e789edb4f303210c813fc56d56377a90\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"f96da09473b52c09125cc9bf7d7d4576ae8229e0\",\n                            \"lessThan\": \"e2e9599f3503df7cf3569d2b6c50d5488fb59435\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"f96da09473b52c09125cc9bf7d7d4576ae8229e0\",\n                            \"lessThan\": \"058a0da4f6d916a79b693384111bb80a90d73763\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"f96da09473b52c09125cc9bf7d7d4576ae8229e0\",\n                            \"lessThan\": \"202900ceeef67458c964c2af6e1427c8e533ea7c\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"f96da09473b52c09125cc9bf7d7d4576ae8229e0\",\n                            \"lessThan\": \"e09299225d5ba3916c91ef70565f7d2187e4cca0\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"kernel/bpf/cgroup.c\",\n                        \"net/core/filter.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"4.13\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"4.13\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.10.249\",\n                            \"lessThanOrEqual\": \"5.10.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.15.199\",\n                            \"lessThanOrEqual\": \"5.15.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.162\",\n                            \"lessThanOrEqual\": \"6.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.157\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.67\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.16.1\",\n                            \"lessThanOrEqual\": \"6.16.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.17\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[],"references":["https://git.kernel.org/stable/c/7847c4140e06f6e87229faae22cc38525334c156","https://git.kernel.org/stable/c/feae34c992eb7191862fb1594c704fbbf650fef8","https://git.kernel.org/stable/c/33660d44e789edb4f303210c813fc56d56377a90","https://git.kernel.org/stable/c/e2e9599f3503df7cf3569d2b6c50d5488fb59435","https://git.kernel.org/stable/c/058a0da4f6d916a79b693384111bb80a90d73763","https://git.kernel.org/stable/c/202900ceeef67458c964c2af6e1427c8e533ea7c","https://git.kernel.org/stable/c/e09299225d5ba3916c91ef70565f7d2187e4cca0"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2025-38591","license":"CVE Program Terms of Use","key":"cve-program:CVE-2025-38591","identifiers":["CVE-2025-38591"]},"retained":false,"historicalAffected":[]}],"coverage":[]}