fkie_cve-2024-53125
Vulnerability from fkie_nvd
Published
2024-12-04 14:15
Modified
2024-12-19 19:15
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved: bpf: sync_linked_regs() must preserve subreg_def Range propagation must not affect subreg_def marks, otherwise the following example is rewritten by verifier incorrectly when BPF_F_TEST_RND_HI32 flag is set: 0: call bpf_ktime_get_ns call bpf_ktime_get_ns 1: r0 &= 0x7fffffff after verifier r0 &= 0x7fffffff 2: w1 = w0 rewrites w1 = w0 3: if w0 < 10 goto +0 --------------> r11 = 0x2f5674a6 (r) 4: r1 >>= 32 r11 <<= 32 (r) 5: r0 = r1 r1 |= r11 (r) 6: exit; if w0 < 0xa goto pc+0 r1 >>= 32 r0 = r1 exit (or zero extension of w1 at (2) is missing for architectures that require zero extension for upper register half). The following happens w/o this patch: - r0 is marked as not a subreg at (0); - w1 is marked as subreg at (2); - w1 subreg_def is overridden at (3) by copy_register_state(); - w1 is read at (5) but mark_insn_zext() does not mark (2) for zero extension, because w1 subreg_def is not set; - because of BPF_F_TEST_RND_HI32 flag verifier inserts random value for hi32 bits of (2) (marked (r)); - this random value is read at (5).
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/60fd3538d2a8fd44c41d25088c0ece3e1fd30659
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/b57ac2d92c1f565743f6890a5b9cf317ed856b09
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/bfe9446ea1d95f6cb7848da19dfd58d2eec6fd84
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/dadf82c1b2608727bcc306843b540cd7414055a7
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/e2ef0f317a52e678fe8fa84b94d6a15b466d6ff0
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/e9bd9c498cb0f5843996dbe5cbce7a1836a83c70
Impacted products
Vendor Product Version


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{
   cveTags: [],
   descriptions: [
      {
         lang: "en",
         value: "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: sync_linked_regs() must preserve subreg_def\n\nRange propagation must not affect subreg_def marks, otherwise the\nfollowing example is rewritten by verifier incorrectly when\nBPF_F_TEST_RND_HI32 flag is set:\n\n  0: call bpf_ktime_get_ns                   call bpf_ktime_get_ns\n  1: r0 &= 0x7fffffff       after verifier   r0 &= 0x7fffffff\n  2: w1 = w0                rewrites         w1 = w0\n  3: if w0 < 10 goto +0     -------------->  r11 = 0x2f5674a6     (r)\n  4: r1 >>= 32                               r11 <<= 32           (r)\n  5: r0 = r1                                 r1 |= r11            (r)\n  6: exit;                                   if w0 < 0xa goto pc+0\n                                             r1 >>= 32\n                                             r0 = r1\n                                             exit\n\n(or zero extension of w1 at (2) is missing for architectures that\n require zero extension for upper register half).\n\nThe following happens w/o this patch:\n- r0 is marked as not a subreg at (0);\n- w1 is marked as subreg at (2);\n- w1 subreg_def is overridden at (3) by copy_register_state();\n- w1 is read at (5) but mark_insn_zext() does not mark (2)\n  for zero extension, because w1 subreg_def is not set;\n- because of BPF_F_TEST_RND_HI32 flag verifier inserts random\n  value for hi32 bits of (2) (marked (r));\n- this random value is read at (5).",
      },
      {
         lang: "es",
         value: "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: bpf: sync_linked_regs() debe preservar subreg_def La propagación del rango no debe afectar a las marcas subreg_def, de lo contrario el siguiente ejemplo es reescrito incorrectamente por el verificador cuando el indicador BPF_F_TEST_RND_HI32 está establecido: 0: llamar a bpf_ktime_get_ns llamar a bpf_ktime_get_ns 1: r0 &amp;= 0x7fffffff después del verificador r0 &amp;= 0x7fffffff 2: w1 = w0 reescribe w1 = w0 3: si w0 &lt; 10 goto +0 --------------&gt; r11 = 0x2f5674a6 (r) 4: r1 &gt;&gt;= 32 r11 &lt;&lt;= 32 (r) 5: r0 = r1 r1 |= r11 (r) 6: salir; si w0 &lt; 0xa goto pc+0 r1 &gt;&gt;= 32 r0 = r1 salir (o falta la extensión cero de w1 en (2) para arquitecturas que requieren extensión cero para la mitad superior del registro). Lo siguiente ocurre sin este parche: - r0 está marcado como no un subreg en (0); - w1 está marcado como subreg en (2); - el subreg_def de w1 es anulado en (3) por copy_register_state(); - w1 se lee en (5) pero mark_insn_zext() no marca (2) para extensión cero, porque el subreg_def de w1 no está configurado; - debido al indicador BPF_F_TEST_RND_HI32, el verificador inserta un valor aleatorio para los bits hi32 de (2) (marcado (r)); - este valor aleatorio se lee en (5).",
      },
   ],
   id: "CVE-2024-53125",
   lastModified: "2024-12-19T19:15:07.613",
   metrics: {},
   published: "2024-12-04T14:15:20.460",
   references: [
      {
         source: "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
         url: "https://git.kernel.org/stable/c/60fd3538d2a8fd44c41d25088c0ece3e1fd30659",
      },
      {
         source: "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
         url: "https://git.kernel.org/stable/c/b57ac2d92c1f565743f6890a5b9cf317ed856b09",
      },
      {
         source: "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
         url: "https://git.kernel.org/stable/c/bfe9446ea1d95f6cb7848da19dfd58d2eec6fd84",
      },
      {
         source: "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
         url: "https://git.kernel.org/stable/c/dadf82c1b2608727bcc306843b540cd7414055a7",
      },
      {
         source: "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
         url: "https://git.kernel.org/stable/c/e2ef0f317a52e678fe8fa84b94d6a15b466d6ff0",
      },
      {
         source: "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
         url: "https://git.kernel.org/stable/c/e9bd9c498cb0f5843996dbe5cbce7a1836a83c70",
      },
   ],
   sourceIdentifier: "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
   vulnStatus: "Awaiting Analysis",
}


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