{"id":"CVE-2026-31636","summary":"rxrpc: fix RESPONSE authenticator parser OOB read","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nrxrpc: fix RESPONSE authenticator parser OOB read\n\nrxgk_verify_authenticator() copies auth_len bytes into a temporary\nbuffer and then passes p + auth_len as the parser limit to\nrxgk_do_verify_authenticator(). Since p is a __be32 *, that inflates the\nparser end pointer by a factor of four and lets malformed RESPONSE\nauthenticators read past the kmalloc() buffer.\n\nDecoded from the original latest-net reproduction logs with\nscripts/decode_stacktrace.sh:\n\nBUG: KASAN: slab-out-of-bounds in rxgk_verify_response()\nCall Trace:\n dump_stack_lvl() [lib/dump_stack.c:123]\n print_report() [mm/kasan/report.c:379 mm/kasan/report.c:482]\n kasan_report() [mm/kasan/report.c:597]\n rxgk_verify_response()\n   [net/rxrpc/rxgk.c:1103 net/rxrpc/rxgk.c:1167\n    net/rxrpc/rxgk.c:1274]\n rxrpc_process_connection()\n   [net/rxrpc/conn_event.c:266 net/rxrpc/conn_event.c:364\n    net/rxrpc/conn_event.c:386]\n process_one_work() [kernel/workqueue.c:3281]\n worker_thread()\n   [kernel/workqueue.c:3353 kernel/workqueue.c:3440]\n kthread() [kernel/kthread.c:436]\n ret_from_fork() [arch/x86/kernel/process.c:164]\n\nAllocated by task 54:\n rxgk_verify_response()\n   [include/linux/slab.h:954 net/rxrpc/rxgk.c:1155\n    net/rxrpc/rxgk.c:1274]\n rxrpc_process_connection()\n   [net/rxrpc/conn_event.c:266 net/rxrpc/conn_event.c:364\n    net/rxrpc/conn_event.c:386]\n\nConvert the byte count to __be32 units before constructing the parser\nlimit.","modified":"2026-06-18T03:56:01.952651103Z","published":"2026-04-24T14:44:50.637Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31636.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/20a188775a9a9982d1987e12660d9b44b40a6c99"},{"type":"WEB","url":"https://git.kernel.org/stable/c/3e3138007887504ee9206d0bfb5acb062c600025"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7875f3d9777bd4e9892c4db830571ab8ac2044c0"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31636.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-31636"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"9d1d2b59341f58126a69b51f9f5f8ccb9f12e54a"},{"fixed":"7875f3d9777bd4e9892c4db830571ab8ac2044c0"},{"fixed":"20a188775a9a9982d1987e12660d9b44b40a6c99"},{"fixed":"3e3138007887504ee9206d0bfb5acb062c600025"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-31636.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.16.0"},{"fixed":"6.18.23"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"6.19.13"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-31636.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H"}]}