fkie_cve-2025-37816
Vulnerability from fkie_nvd
Published
2025-05-08 07:15
Modified
2025-05-08 14:39
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved: mei: vsc: Fix fortify-panic caused by invalid counted_by() use gcc 15 honors the __counted_by(len) attribute on vsc_tp_packet.buf[] and the vsc-tp.c code is using this in a wrong way. len does not contain the available size in the buffer, it contains the actual packet length *without* the crc. So as soon as vsc_tp_xfer() tries to add the crc to buf[] the fortify-panic handler gets triggered: [ 80.842193] memcpy: detected buffer overflow: 4 byte write of buffer size 0 [ 80.842243] WARNING: CPU: 4 PID: 272 at lib/string_helpers.c:1032 __fortify_report+0x45/0x50 ... [ 80.843175] __fortify_panic+0x9/0xb [ 80.843186] vsc_tp_xfer.cold+0x67/0x67 [mei_vsc_hw] [ 80.843210] ? seqcount_lockdep_reader_access.constprop.0+0x82/0x90 [ 80.843229] ? lockdep_hardirqs_on+0x7c/0x110 [ 80.843250] mei_vsc_hw_start+0x98/0x120 [mei_vsc] [ 80.843270] mei_reset+0x11d/0x420 [mei] The easiest fix would be to just drop the counted-by but with the exception of the ack buffer in vsc_tp_xfer_helper() which only contains enough room for the packet-header, all other uses of vsc_tp_packet always use a buffer of VSC_TP_MAX_XFER_SIZE bytes for the packet. Instead of just dropping the counted-by, split the vsc_tp_packet struct definition into a header and a full-packet definition and use a fixed size buf[] in the packet definition, this way fortify-source buffer overrun checking still works when enabled.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/00f1cc14da0f06d2897b8c528df7c7dcf1b8da50
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/3e243378f27cc7d11682a3ad720228b0723affa5
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/ac04663c67f244810b3492e9ecd9f7cdbefeca2d
Impacted products
Vendor Product Version


To clipboard 

{
  "cveTags": [],
  "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."
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: mei: vsc: Se corrige el problema de fortify-panic causado por el uso no v\u00e1lido de counted_by() gcc 15 respeta el atributo __counted_by(len) en vsc_tp_packet.buf[] y el c\u00f3digo vsc-tp.c lo usa de manera incorrecta. len no contiene el tama\u00f1o disponible en el b\u00fafer, contiene la longitud real del paquete *sin* el crc. Entonces, tan pronto como vsc_tp_xfer() intenta agregar el crc a buf[], se activa el controlador fortify-panic: [80.842193] memcpy: desbordamiento de b\u00fafer detectado: escritura de 4 bytes de tama\u00f1o de b\u00fafer 0 [80.842243] ADVERTENCIA: CPU: 4 PID: 272 en lib/string_helpers.c:1032 __fortify_report+0x45/0x50 ... [80.843175] __fortify_panic+0x9/0xb [80.843186] vsc_tp_xfer.cold+0x67/0x67 [mei_vsc_hw] [80.843210] ? lockdep_hardirqs_on+0x7c/0x110 [ 80.843250] mei_vsc_hw_start+0x98/0x120 [mei_vsc] [ 80.843270] mei_reset+0x11d/0x420 [mei] La soluci\u00f3n m\u00e1s f\u00e1cil ser\u00eda simplemente omitir el conteo, pero con la excepci\u00f3n del b\u00fafer de reconocimiento en vsc_tp_xfer_helper() que solo contiene suficiente espacio para el encabezado del paquete, todos los dem\u00e1s usos de vsc_tp_packet siempre usan un b\u00fafer de VSC_TP_MAX_XFER_SIZE bytes para el paquete. En lugar de simplemente eliminar el conteo, divida la definici\u00f3n de la estructura vsc_tp_packet en un encabezado y una definici\u00f3n de paquete completo y use un buf[] de tama\u00f1o fijo en la definici\u00f3n del paquete, de esta manera la verificaci\u00f3n de desbordamiento del b\u00fafer de fortify-source a\u00fan funciona cuando est\u00e1 habilitada."
    }
  ],
  "id": "CVE-2025-37816",
  "lastModified": "2025-05-08T14:39:09.683",
  "metrics": {},
  "published": "2025-05-08T07:15:52.837",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/00f1cc14da0f06d2897b8c528df7c7dcf1b8da50"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/3e243378f27cc7d11682a3ad720228b0723affa5"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/ac04663c67f244810b3492e9ecd9f7cdbefeca2d"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Awaiting Analysis"
}


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