{"id":"CVE-2025-37816","state":"PUBLISHED","title":"mei: vsc: Fix fortify-panic caused by invalid counted_by() use","description":"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.","publishedAt":"2025-05-08T06:26:12.063Z","updatedAt":"2026-05-11T21:15:41.996Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"566f5ca9768075e453b7b51a397733968df4287d","status":"affected","lessThan":"3e243378f27cc7d11682a3ad720228b0723affa5","versionType":"git"},{"version":"566f5ca9768075e453b7b51a397733968df4287d","status":"affected","lessThan":"ac04663c67f244810b3492e9ecd9f7cdbefeca2d","versionType":"git"},{"version":"566f5ca9768075e453b7b51a397733968df4287d","status":"affected","lessThan":"00f1cc14da0f06d2897b8c528df7c7dcf1b8da50","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/misc/mei/vsc-tp.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.8","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.8","versionType":"semver"},{"version":"6.12.26","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.14.5","status":"unaffected","lessThanOrEqual":"6.14.*","versionType":"semver"},{"version":"6.15","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/misc/mei/vsc-tp.c"]}],"references":["https://git.kernel.org/stable/c/3e243378f27cc7d11682a3ad720228b0723affa5","https://git.kernel.org/stable/c/ac04663c67f244810b3492e9ecd9f7cdbefeca2d","https://git.kernel.org/stable/c/00f1cc14da0f06d2897b8c528df7c7dcf1b8da50"],"weaknesses":[],"ingestedAt":"2026-10-29T20:09:03.054Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2025/37xxx/CVE-2025-37816.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2025-37816","state":"PUBLISHED","datePublished":"2025-05-08T06:26:12.063Z","dateUpdated":"2026-05-11T21:15:41.996Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2025-04-16T04:51:23.946Z"},"containers":{"cna":{"title":"mei: vsc: Fix fortify-panic caused by invalid counted_by() use","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"566f5ca9768075e453b7b51a397733968df4287d","status":"affected","lessThan":"3e243378f27cc7d11682a3ad720228b0723affa5","versionType":"git"},{"version":"566f5ca9768075e453b7b51a397733968df4287d","status":"affected","lessThan":"ac04663c67f244810b3492e9ecd9f7cdbefeca2d","versionType":"git"},{"version":"566f5ca9768075e453b7b51a397733968df4287d","status":"affected","lessThan":"00f1cc14da0f06d2897b8c528df7c7dcf1b8da50","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/misc/mei/vsc-tp.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.8","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.8","versionType":"semver"},{"version":"6.12.26","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.14.5","status":"unaffected","lessThanOrEqual":"6.14.*","versionType":"semver"},{"version":"6.15","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/misc/mei/vsc-tp.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/3e243378f27cc7d11682a3ad720228b0723affa5"},{"url":"https://git.kernel.org/stable/c/ac04663c67f244810b3492e9ecd9f7cdbefeca2d"},{"url":"https://git.kernel.org/stable/c/00f1cc14da0f06d2897b8c528df7c7dcf1b8da50"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-05-11T21:15:41.996Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.8","versionEndExcluding":"6.12.26"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.8","versionEndExcluding":"6.14.5"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.8","versionEndExcluding":"6.15"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}