{"id":"CVE-2026-23433","summary":"arm_mpam: Fix null pointer dereference when restoring bandwidth counters","details":"In the Linux kernel, the following vulnerability has been resolved:\n\narm_mpam: Fix null pointer dereference when restoring bandwidth counters\n\nWhen an MSC supporting memory bandwidth monitoring is brought offline and\nthen online, mpam_restore_mbwu_state() calls __ris_msmon_read() via ipi to\nrestore the configuration of the bandwidth counters. It doesn't care about\nthe value read, mbwu_arg.val, and doesn't set it leading to a null pointer\ndereference when __ris_msmon_read() adds to it. This results in a kernel\noops with a call trace such as:\n\nCall trace:\n__ris_msmon_read+0x19c/0x64c (P)\nmpam_restore_mbwu_state+0xa0/0xe8\nsmp_call_on_cpu_callback+0x1c/0x38\nprocess_one_work+0x154/0x4b4\nworker_thread+0x188/0x310\nkthread+0x11c/0x130\nret_from_fork+0x10/0x20\n\nProvide a local variable for val to avoid __ris_msmon_read() dereferencing\na null pointer when adding to val.","modified":"2026-07-08T07:09:45.991584748Z","published":"2026-04-03T15:15:18.757Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23433.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/4ad79c874e53ebb7fe3b8ae7ac6c858a2121f415"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ac3e12bc195786d3d44d730b5b2259fd36191848"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23433.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-23433"},{"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":"41e8a14950e1732af51cfec8fa09f8ded02a5ca9"},{"fixed":"ac3e12bc195786d3d44d730b5b2259fd36191848"},{"fixed":"4ad79c874e53ebb7fe3b8ae7ac6c858a2121f415"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-23433.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"6.19.10"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-23433.json"}}],"schema_version":"1.7.5"}