{"id":"CVE-2025-37816","summary":"mei: vsc: Fix fortify-panic caused by invalid counted_by() use","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nmei: vsc: Fix fortify-panic caused by invalid counted_by() use\n\ngcc 15 honors the __counted_by(len) attribute on vsc_tp_packet.buf[]\nand the vsc-tp.c code is using this in a wrong way. len does not contain\nthe available size in the buffer, it contains the actual packet length\n*without* the crc. So as soon as vsc_tp_xfer() tries to add the crc to\nbuf[] the fortify-panic handler gets triggered:\n\n[   80.842193] memcpy: detected buffer overflow: 4 byte write of buffer size 0\n[   80.842243] WARNING: CPU: 4 PID: 272 at lib/string_helpers.c:1032 __fortify_report+0x45/0x50\n...\n[   80.843175]  __fortify_panic+0x9/0xb\n[   80.843186]  vsc_tp_xfer.cold+0x67/0x67 [mei_vsc_hw]\n[   80.843210]  ? seqcount_lockdep_reader_access.constprop.0+0x82/0x90\n[   80.843229]  ? lockdep_hardirqs_on+0x7c/0x110\n[   80.843250]  mei_vsc_hw_start+0x98/0x120 [mei_vsc]\n[   80.843270]  mei_reset+0x11d/0x420 [mei]\n\nThe easiest fix would be to just drop the counted-by but with the exception\nof the ack buffer in vsc_tp_xfer_helper() which only contains enough room\nfor the packet-header, all other uses of vsc_tp_packet always use a buffer\nof VSC_TP_MAX_XFER_SIZE bytes for the packet.\n\nInstead of just dropping the counted-by, split the vsc_tp_packet struct\ndefinition into a header and a full-packet definition and use a fixed\nsize buf[] in the packet definition, this way fortify-source buffer\noverrun checking still works when enabled.","modified":"2026-03-20T12:42:29.051237Z","published":"2025-05-08T06:26:12.063Z","related":["SUSE-SU-2025:02254-1","SUSE-SU-2025:02307-1","SUSE-SU-2025:02333-1"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/37xxx/CVE-2025-37816.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/00f1cc14da0f06d2897b8c528df7c7dcf1b8da50"},{"type":"WEB","url":"https://git.kernel.org/stable/c/3e243378f27cc7d11682a3ad720228b0723affa5"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ac04663c67f244810b3492e9ecd9f7cdbefeca2d"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/37xxx/CVE-2025-37816.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-37816"},{"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":"566f5ca9768075e453b7b51a397733968df4287d"},{"fixed":"3e243378f27cc7d11682a3ad720228b0723affa5"},{"fixed":"ac04663c67f244810b3492e9ecd9f7cdbefeca2d"},{"fixed":"00f1cc14da0f06d2897b8c528df7c7dcf1b8da50"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2025-37816.json"}}],"schema_version":"1.7.5"}