fkie_cve-2022-50168
Vulnerability from fkie_nvd
Published
2025-06-18 11:15
Modified
2025-06-18 13:47
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
bpf, x86: fix freeing of not-finalized bpf_prog_pack
syzbot reported a few issues with bpf_prog_pack [1], [2]. This only happens
with multiple subprogs. In jit_subprogs(), we first call bpf_int_jit_compile()
on each sub program. And then, we call it on each sub program again. jit_data
is not freed in the first call of bpf_int_jit_compile(). Similarly we don't
call bpf_jit_binary_pack_finalize() in the first call of bpf_int_jit_compile().
If bpf_int_jit_compile() failed for one sub program, we will call
bpf_jit_binary_pack_finalize() for this sub program. However, we don't have a
chance to call it for other sub programs. Then we will hit "goto out_free" in
jit_subprogs(), and call bpf_jit_free on some subprograms that haven't got
bpf_jit_binary_pack_finalize() yet.
At this point, bpf_jit_binary_pack_free() is called and the whole 2MB page is
freed erroneously.
Fix this with a custom bpf_jit_free() for x86_64, which calls
bpf_jit_binary_pack_finalize() if necessary. Also, with custom
bpf_jit_free(), bpf_prog_aux->use_bpf_prog_pack is not needed any more,
remove it.
[1] https://syzkaller.appspot.com/bug?extid=2f649ec6d2eea1495a8f
[2] https://syzkaller.appspot.com/bug?extid=87f65c75f4a72db05445
References
Impacted products
| Vendor | Product | Version |
|---|
{
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf, x86: fix freeing of not-finalized bpf_prog_pack\n\nsyzbot reported a few issues with bpf_prog_pack [1], [2]. This only happens\nwith multiple subprogs. In jit_subprogs(), we first call bpf_int_jit_compile()\non each sub program. And then, we call it on each sub program again. jit_data\nis not freed in the first call of bpf_int_jit_compile(). Similarly we don\u0027t\ncall bpf_jit_binary_pack_finalize() in the first call of bpf_int_jit_compile().\n\nIf bpf_int_jit_compile() failed for one sub program, we will call\nbpf_jit_binary_pack_finalize() for this sub program. However, we don\u0027t have a\nchance to call it for other sub programs. Then we will hit \"goto out_free\" in\njit_subprogs(), and call bpf_jit_free on some subprograms that haven\u0027t got\nbpf_jit_binary_pack_finalize() yet.\n\nAt this point, bpf_jit_binary_pack_free() is called and the whole 2MB page is\nfreed erroneously.\n\nFix this with a custom bpf_jit_free() for x86_64, which calls\nbpf_jit_binary_pack_finalize() if necessary. Also, with custom\nbpf_jit_free(), bpf_prog_aux-\u003euse_bpf_prog_pack is not needed any more,\nremove it.\n\n[1] https://syzkaller.appspot.com/bug?extid=2f649ec6d2eea1495a8f\n[2] https://syzkaller.appspot.com/bug?extid=87f65c75f4a72db05445"
},
{
"lang": "es",
"value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: bpf, x86: se corrige la liberaci\u00f3n de bpf_prog_pack no finalizado. syzbot report\u00f3 algunos problemas con bpf_prog_pack [1], [2]. Esto solo ocurre con varios subprogramas. En jit_subprogs(), primero llamamos a bpf_int_jit_compile() en cada subprograma. Y luego, lo volvemos a llamar en cada subprograma. jit_data no se libera en la primera llamada de bpf_int_jit_compile(). De igual manera, no llamamos a bpf_jit_binary_pack_finalize() en la primera llamada de bpf_int_jit_compile(). Si bpf_int_jit_compile() falla en un subprograma, llamaremos a bpf_jit_binary_pack_finalize() para este subprograma. Sin embargo, no podemos llamarlo para otros subprogramas. Luego, pulsaremos \"goto out_free\" en jit_subprogs() y llamaremos a bpf_jit_free en algunos subprogramas que a\u00fan no tienen bpf_jit_binary_pack_finalize(). En este punto, se llama a bpf_jit_binary_pack_free() y se libera la p\u00e1gina completa de 2 MB por error. Se puede solucionar con un bpf_jit_free() personalizado para x86_64, que llama a bpf_jit_binary_pack_finalize() si es necesario. Adem\u00e1s, con bpf_jit_free() personalizado, bpf_prog_aux-\u0026gt;use_bpf_prog_pack ya no es necesario; elim\u00ednelo. [1] https://syzkaller.appspot.com/bug?extid=2f649ec6d2eea1495a8f [2] https://syzkaller.appspot.com/bug?extid=87f65c75f4a72db05445"
}
],
"id": "CVE-2022-50168",
"lastModified": "2025-06-18T13:47:40.833",
"metrics": {},
"published": "2025-06-18T11:15:47.117",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/1d5f82d9dd477d5c66e0214a68c3e4f308eadd6d"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/60e66074812dde9cde3d99cdd3caa9e40f1a4516"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/f91ce608a79c0db3e72bd63c23e011a9ebc31505"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Awaiting Analysis"
}
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- 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.
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