Описание
In the Linux kernel, the following vulnerability has been resolved:
xsk: Harden userspace-supplied xdp_desc validation
Turned out certain clearly invalid values passed in xdp_desc from
userspace can pass xp_{,un}aligned_validate_desc() and then lead
to UBs or just invalid frames to be queued for xmit.
desc->len close to U32_MAX with a non-zero pool->tx_metadata_len
can cause positive integer overflow and wraparound, the same way low
enough desc->addr with a non-zero pool->tx_metadata_len can cause
negative integer overflow. Both scenarios can then pass the
validation successfully.
This doesn't happen with valid XSk applications, but can be used
to perform attacks.
Always promote desc->len to u64 first to exclude positive
overflows of it. Use explicit check_{add,sub}_overflow() when
validating desc->addr (which is u64 already).
bloat-o-meter reports a little growth of the code size:
add/remove: 0/0 grow/shrink: 2/1 up/down: 60/-16 (44)
Function old new delta
xskq_cons_peek_desc 299 330 +31
xsk_tx_peek_release_desc_batch 973 1002 +29
xsk_generic_xmit 3148 3132 -16
but hopefully this doesn't hurt the performance much.
Integer overflow vulnerabilities were found in the Linux kernel's XDP socket descriptor validation. A local user can trigger these issues by supplying crafted xdp_desc values through AF_XDP sockets—either desc->len values near U32_MAX that overflow when added to metadata length, or extremely low desc->addr values that underflow when subtracting metadata length. Both bypass validation checks and allow invalid frames to be queued for transmission or cause undefined behavior, resulting in denial of service.
Отчет
AF_XDP allows userspace to submit packet descriptors for zero-copy transmission. The validation functions check that descriptor addresses and lengths are within pool boundaries. When tx_metadata_len is non-zero, calculations add it to desc->len or subtract it from desc->addr. Since desc->len is u32, values near U32_MAX can wrap around when metadata is added, making invalid large sizes appear valid. Similarly, low desc->addr values can underflow during subtraction, passing validation incorrectly. While legitimate XDP applications don't send such values, attackers can exploit these overflows. The fix promotes desc->len to u64 before arithmetic and uses explicit overflow checking for desc->addr calculations.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat Enterprise Linux 10 | kernel | Fix deferred | ||
| Red Hat Enterprise Linux 6 | kernel | Not affected | ||
| Red Hat Enterprise Linux 7 | kernel | Not affected | ||
| Red Hat Enterprise Linux 7 | kernel-rt | Not affected | ||
| Red Hat Enterprise Linux 8 | kernel | Not affected | ||
| Red Hat Enterprise Linux 8 | kernel-rt | Not affected | ||
| Red Hat Enterprise Linux 9 | kernel | Fix deferred | ||
| Red Hat Enterprise Linux 9 | kernel-rt | Fix deferred |
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Дополнительная информация
Статус:
EPSS
5.5 Medium
CVSS3
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: xsk: Harden userspace-supplied xdp_desc validation Turned out certain clearly invalid values passed in xdp_desc from userspace can pass xp_{,un}aligned_validate_desc() and then lead to UBs or just invalid frames to be queued for xmit. desc->len close to ``U32_MAX`` with a non-zero pool->tx_metadata_len can cause positive integer overflow and wraparound, the same way low enough desc->addr with a non-zero pool->tx_metadata_len can cause negative integer overflow. Both scenarios can then pass the validation successfully. This doesn't happen with valid XSk applications, but can be used to perform attacks. Always promote desc->len to ``u64`` first to exclude positive overflows of it. Use explicit check_{add,sub}_overflow() when validating desc->addr (which is ``u64`` already). bloat-o-meter reports a little growth of the code size: add/remove: 0/0 grow/shrink: 2/1 up/down: 60/-16 (44) Function ...
In the Linux kernel, the following vulnerability has been resolved: xsk: Harden userspace-supplied xdp_desc validation Turned out certain clearly invalid values passed in xdp_desc from userspace can pass xp_{,un}aligned_validate_desc() and then lead to UBs or just invalid frames to be queued for xmit. desc->len close to ``U32_MAX`` with a non-zero pool->tx_metadata_len can cause positive integer overflow and wraparound, the same way low enough desc->addr with a non-zero pool->tx_metadata_len can cause negative integer overflow. Both scenarios can then pass the validation successfully. This doesn't happen with valid XSk applications, but can be used to perform attacks. Always promote desc->len to ``u64`` first to exclude positive overflows of it. Use explicit check_{add,sub}_overflow() when validating desc->addr (which is ``u64`` already). bloat-o-meter reports a little growth of the code size: add/remove: 0/0 grow/shrink: 2/1 up/down: 60/-16 (44) Function
In the Linux kernel, the following vulnerability has been resolved: x ...
In the Linux kernel, the following vulnerability has been resolved: xsk: Harden userspace-supplied xdp_desc validation Turned out certain clearly invalid values passed in xdp_desc from userspace can pass xp_{,un}aligned_validate_desc() and then lead to UBs or just invalid frames to be queued for xmit. desc->len close to ``U32_MAX`` with a non-zero pool->tx_metadata_len can cause positive integer overflow and wraparound, the same way low enough desc->addr with a non-zero pool->tx_metadata_len can cause negative integer overflow. Both scenarios can then pass the validation successfully. This doesn't happen with valid XSk applications, but can be used to perform attacks. Always promote desc->len to ``u64`` first to exclude positive overflows of it. Use explicit check_{add,sub}_overflow() when validating desc->addr (which is ``u64`` already). bloat-o-meter reports a little growth of the code size: add/remove: 0/0 grow/shrink: 2/1 up/down: 60/-16 (44) Function ...
Уязвимость ядра операционной системы Linux, связанная с недостаточной проверкой входных данных, позволяющая нарушителю вызвать отказ в обслуживании
EPSS
5.5 Medium
CVSS3