{"id":"CVE-2026-43416","title":"powerpc, perf: Check that current->mm is alive before getting user callchain","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\npowerpc, perf: Check that current->mm is alive before getting user callchain\n\nIt may happen that mm is already released, which leads to kernel panic.\nThis adds the NULL…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 20002ded4d937ca87aca6253b874920a96a763c4 < 98074e16742ae87fb82e234b419783c5ffc9baea","Linux >= 20002ded4d937ca87aca6253b874920a96a763c4 < 7e5f60b8cfc02a2b23a40a5f5fd2fa81d010e737","Linux >= 20002ded4d937ca87aca6253b874920a96a763c4 < e9bbfb4bfa86c6b5515b868d6982ac60505d7e39","Linux 2.6.32"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-11-06T15:37:49.414507Z"},"published":"2026-05-08","updated":"2026-11-06","sourceUpdated":"2026-11-06T15:42:52.602Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-43416","references":[{"url":"https://git.kernel.org/stable/c/98074e16742ae87fb82e234b419783c5ffc9baea"},{"url":"https://git.kernel.org/stable/c/7e5f60b8cfc02a2b23a40a5f5fd2fa81d010e737"},{"url":"https://git.kernel.org/stable/c/e9bbfb4bfa86c6b5515b868d6982ac60505d7e39"}],"tags":["cve.org"],"epss":0.00121,"epssPercentile":0.01901,"ingestedAt":"2026-11-06T15:54:03.922Z","slug":"CVE-2026-43416","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\npowerpc, perf: Check that current->mm is alive before getting user callchain\n\nIt may happen that mm is already released, which leads to kernel panic.\nThis adds the NULL check for current->mm, similarly to\ncommit 20afc60f892d (\"x86, perf: Check that current->mm is alive before getting user callchain\").\n\nI was getting this panic when running a profiling BPF program\n(profile.py from bcc-tools):\n\n    [26215.051935] Kernel attempted to read user page (588) - exploit attempt? (uid: 0)\n    [26215.051950] BUG: Kernel NULL pointer dereference on read at 0x00000588\n    [26215.051952] Faulting instruction address: 0xc00000000020fac0\n    [26215.051957] Oops: Kernel access of bad area, sig: 11 [#1]\n    [...]\n    [26215.052049] Call Trace:\n    [26215.052050] [c000000061da6d30] [c00000000020fc10] perf_callchain_user_64+0x2d0/0x490 (unreliable)\n    [26215.052054] [c000000061da6dc0] [c00000000020f92c] perf_callchain_user+0x1c/0x30\n    [26215.052057] [c000000061da6de0] [c0000000005ab2a0] get_perf_callchain+0x100/0x360\n    [26215.052063] [c000000061da6e70] [c000000000573bc8] bpf_get_stackid+0x88/0xf0\n    [26215.052067] [c000000061da6ea0] [c008000000042258] bpf_prog_16d4ab9ab662f669_do_perf_event+0xf8/0x274\n    [...]\n\nIn addition, move storing the top-level stack entry to generic\nperf_callchain_user to make sure the top-evel entry is always captured,\neven if current->mm is NULL.\n\n[Maddy: fixed message to avoid checkpatch format style error]\n\n## Affected\n\n- `Linux >= 20002ded4d937ca87aca6253b874920a96a763c4 < 98074e16742ae87fb82e234b419783c5ffc9baea`\n- `Linux >= 20002ded4d937ca87aca6253b874920a96a763c4 < 7e5f60b8cfc02a2b23a40a5f5fd2fa81d010e737`\n- `Linux >= 20002ded4d937ca87aca6253b874920a96a763c4 < e9bbfb4bfa86c6b5515b868d6982ac60505d7e39`\n- `Linux 2.6.32`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}