Описание
In the Linux kernel, the following vulnerability has been resolved:
net: wwan: mhi_wwan_mbim: guard against a cyclic NDP chain
The NDP traversal in mhi_mbim_rx() only stops when wNextNdpIndex is
zero. Nothing requires the offsets to advance, so a modem that
points an NDP at itself, or at an earlier NDP, keeps the loop
spinning forever on one CPU.
Break out when the next NDP offset is not larger than the current
one.
Verified in a QEMU guest with a fault injector feeding the driver's
receive callback an NTB whose single NDP points at itself: the
unpatched driver spins in mhi_mbim_rx() with one CPU pinned at 100%
and the thread never returns. With this check the loop terminates
within one iteration.
Changes in v2: move the non-increasing check to the wNextNdpIndex
retrieval site, as suggested by Loic Poulain, instead of tracking
the previous offset in a separate variable.
A flaw was found in the Linux kernel's MHI Mobile Broadband Interface Model (MBIM) driver. This flaw allows a malicious or compromised modem to cause a Denial of Service (DoS) by sending network frames with cyclic Network Datagram Pointer (NDP) chains that do not advance. Processing these cyclic descriptors causes an infinite loop in the driver, pinning a CPU core at full capacity and hanging the receiving thread.
Отчет
A low-impact denial of service flaw was found in the Linux kernel MHI WWAN MBIM driver (mhi_wwan_mbim). When the driver receives a Network Transfer Block (NTB), the NDP traversal loop in mhi_mbim_rx() only stops when the next NDP index is zero and does not verify that the offsets advance. A malicious or compromised modem can therefore deliver frames with a cyclic or self-referential Network Datagram Pointer (NDP) chain, driving the driver into an infinite loop that pins a CPU core at 100% and hangs the receive thread. Confidentiality and integrity are not affected. Red Hat rates this flaw as low severity because the attack requires a malicious or compromised modem attached over the MHI bus; ordinary network traffic does not control the NDP metadata produced by modem firmware, so an arbitrary remote peer cannot trigger the loop. The MHI MBIM driver is present in Red Hat Enterprise Linux 9 (from 9.3 onward), Red Hat Enterprise Linux 10, Red Hat In-Vehicle OS 2, and the RHEL CoreOS 9 based OpenShift Container Platform releases (4.16 and later, including 5.x), which are affected. Fixes for these streams are currently deferred to a future update; the residual risk of deferral is limited to a local denial of service (CPU exhaustion on one core) that requires attacker-controlled modem hardware or firmware. Red Hat Enterprise Linux 6, 7, 8, and RHEL 9.2, as well as OpenShift Container Platform 4.15 and earlier (including the RHEL CoreOS 8 based releases), are not affected because the vulnerable driver code is not present in those versions.
Меры по смягчению последствий
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
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 | Not affected | ||
| Red Hat OpenShift Container Platform 4 | openshift/ose-rhel-coreos-8 | Not affected | ||
| Red Hat OpenShift Container Platform 4 | openshift/ose-rhel-coreos-9 | 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: net: wwan: mhi_wwan_mbim: guard against a cyclic NDP chain The NDP traversal in mhi_mbim_rx() only stops when wNextNdpIndex is zero. Nothing requires the offsets to advance, so a modem that points an NDP at itself, or at an earlier NDP, keeps the loop spinning forever on one CPU. Break out when the next NDP offset is not larger than the current one. Verified in a QEMU guest with a fault injector feeding the driver's receive callback an NTB whose single NDP points at itself: the unpatched driver spins in mhi_mbim_rx() with one CPU pinned at 100% and the thread never returns. With this check the loop terminates within one iteration. Changes in v2: move the non-increasing check to the wNextNdpIndex retrieval site, as suggested by Loic Poulain, instead of tracking the previous offset in a separate variable.
In the Linux kernel, the following vulnerability has been resolved: net: wwan: mhi_wwan_mbim: guard against a cyclic NDP chain The NDP traversal in mhi_mbim_rx() only stops when wNextNdpIndex is zero. Nothing requires the offsets to advance, so a modem that points an NDP at itself, or at an earlier NDP, keeps the loop spinning forever on one CPU. Break out when the next NDP offset is not larger than the current one. Verified in a QEMU guest with a fault injector feeding the driver's receive callback an NTB whose single NDP points at itself: the unpatched driver spins in mhi_mbim_rx() with one CPU pinned at 100% and the thread never returns. With this check the loop terminates within one iteration. Changes in v2: move the non-increasing check to the wNextNdpIndex retrieval site, as suggested by Loic Poulain, instead of tracking the previous offset in a separate variable.
In the Linux kernel, the following vulnerability has been resolved: n ...
In the Linux kernel, the following vulnerability has been resolved: net: wwan: mhi_wwan_mbim: guard against a cyclic NDP chain The NDP traversal in mhi_mbim_rx() only stops when wNextNdpIndex is zero. Nothing requires the offsets to advance, so a modem that points an NDP at itself, or at an earlier NDP, keeps the loop spinning forever on one CPU. Break out when the next NDP offset is not larger than the current one. Verified in a QEMU guest with a fault injector feeding the driver's receive callback an NTB whose single NDP points at itself: the unpatched driver spins in mhi_mbim_rx() with one CPU pinned at 100% and the thread never returns. With this check the loop terminates within one iteration. Changes in v2: move the non-increasing check to the wNextNdpIndex retrieval site, as suggested by Loic Poulain, instead of tracking the previous offset in a separate variable.
EPSS
5.5 Medium
CVSS3