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
Impacted products
| Vendor | Product | Version |
|---|
{
"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 \u0026= 0x7fffffff after verifier r0 \u0026= 0x7fffffff\n 2: w1 = w0 rewrites w1 = w0\n 3: if w0 \u003c 10 goto +0 --------------\u003e r11 = 0x2f5674a6 (r)\n 4: r1 \u003e\u003e= 32 r11 \u003c\u003c= 32 (r)\n 5: r0 = r1 r1 |= r11 (r)\n 6: exit; if w0 \u003c 0xa goto pc+0\n r1 \u003e\u003e= 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 propagaci\u00f3n 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 est\u00e1 establecido: 0: llamar a bpf_ktime_get_ns llamar a bpf_ktime_get_ns 1: r0 \u0026amp;= 0x7fffffff despu\u00e9s del verificador r0 \u0026amp;= 0x7fffffff 2: w1 = w0 reescribe w1 = w0 3: si w0 \u0026lt; 10 goto +0 --------------\u0026gt; r11 = 0x2f5674a6 (r) 4: r1 \u0026gt;\u0026gt;= 32 r11 \u0026lt;\u0026lt;= 32 (r) 5: r0 = r1 r1 |= r11 (r) 6: salir; si w0 \u0026lt; 0xa goto pc+0 r1 \u0026gt;\u0026gt;= 32 r0 = r1 salir (o falta la extensi\u00f3n cero de w1 en (2) para arquitecturas que requieren extensi\u00f3n cero para la mitad superior del registro). Lo siguiente ocurre sin este parche: - r0 est\u00e1 marcado como no un subreg en (0); - w1 est\u00e1 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 extensi\u00f3n cero, porque el subreg_def de w1 no est\u00e1 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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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
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- Confirmed: The vulnerability is confirmed from an analyst perspective.
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- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.