{"id":"CVE-2026-64402","title":"In the Linux kernel, the following vulnerability has been resolved:\n\ncoresight: ultrasoc-smb: Fix OOB write in smb_sync_perf_buffer()\n\nWhen the SMB sink is used as a perf AUX sink, smb_update_buffer() calls\nsmb_sync_perf_buffer() to copy…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\ncoresight: ultrasoc-smb: Fix OOB write in smb_sync_perf_buffer()\n\nWhen the SMB sink is used as a perf AUX sink, smb_update_buffer() calls\nsmb_sync_perf_buffer() to copy…","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-787"],"vendor":"linux","product":"linux_kernel","affected":["linux_kernel >= 6.3, < 6.6.145","linux_kernel >= 6.7, < 6.12.96","linux_kernel >= 6.13, < 6.18.39","linux_kernel >= 6.19, < 7.1.4"],"patched":["linux_kernel 7.1.4"],"published":"2026-07-25","updated":"2026-09-04","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-64402","references":[{"url":"https://git.kernel.org/stable/c/38dbc8db8341ccdf8e1e1a067453d33ad751864b","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/4c5a0a946373da99a80398289b28845b5ae40cd1","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/661a019ac0413ecec9e5d1dfcc12fbca8e78d5fb","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/98495b5a4d77dd22e106f462b76e1093a55b29a7","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/daf6246ab988fc8bdc82ad7c8d0b1c182d11b15f","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd"],"epss":0.00129,"epssPercentile":0.02863,"ingestedAt":"2026-09-05T13:39:57.942Z","slug":"CVE-2026-64402","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\ncoresight: ultrasoc-smb: Fix OOB write in smb_sync_perf_buffer()\n\nWhen the SMB sink is used as a perf AUX sink, smb_update_buffer() calls\nsmb_sync_perf_buffer() to copy hardware trace data into the perf AUX ring\nbuffer pages. It derives pg_idx = head >> PAGE_SHIFT from @head, which is\nhandle->head, and indexes dst_pages[pg_idx]. The pg_idx %= nr_pages\nnormalization is only applied after the first loop iteration.\n\nThis leaves the initial page index underived from the buffer size, which\ncan result in an out-of-bounds write past dst_pages[] when head exceeds\nthe AUX buffer size.\n\nNormalize head modulo the AUX buffer size before deriving the page index\nand offset, mirroring tmc_etr_sync_perf_buffer().\n\n## Affected\n\n- `linux_kernel >= 6.3, < 6.6.145`\n- `linux_kernel >= 6.7, < 6.12.96`\n- `linux_kernel >= 6.13, < 6.18.39`\n- `linux_kernel >= 6.19, < 7.1.4`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `linux_kernel 7.1.4`","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}