Описание
In the Linux kernel, the following vulnerability has been resolved:
nvme: add missing SRCU grace period in error path
nvme_alloc_ns() error path at out_unlink_ns removes ns from the
namespace head siblings list with list_del_rcu(&ns->siblings) but
does not wait for SRCU readers before freeing the namespace struct.
Multipath code iterates the head->list under srcu_read_lock() in
nvme_find_path() and nvme_mpath_revalidate_paths(), so a concurrent
reader can still hold a reference to ns when kfree(ns) runs.
The normal removal path in nvme_ns_remove() correctly calls
synchronize_srcu(&ns->head->srcu) after list_del_rcu() to wait for
in-progress readers. Add the same grace period in the error path.
A flaw was found in the NVMe (Non-Volatile Memory Express) driver of the Linux kernel. The nvme_alloc_ns() function's error handling path fails to wait for all SRCU (Sleepable Read-Copy Update) readers to complete before freeing a namespace structure. This oversight allows a concurrent reader to access a freed memory region, leading to a use-after-free vulnerability. A local attacker could potentially exploit this to cause a system crash or achieve arbitrary code execution.
Отчет
This vulnerability is rated with an Important severity impact because, although exploitation requires local privileges rather than remote access, successful execution can compromise kernel memory integrity and allow arbitrary code execution. The risk manifests on systems configured with NVMe storage subsystems, where namespace error recovery operations can allow concurrent readers to reference released data structures. Standard installations operating on NVMe storage are susceptible during namespace teardown failures, whereas enterprise Linux 7 and earlier releases lack the vulnerable multipath synchronization logic.
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 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 9 | kernel-rt | Affected | ||
| Red Hat OpenShift Container Platform 4 | openshift/ose-rhel-coreos-8 | Affected | ||
| Red Hat OpenShift Container Platform 5 | openshift/ose-rhel-coreos-9 | Affected | ||
| Red Hat Enterprise Linux 10 | kernel | Fixed | RHSA-2026:76738 | 08.10.2026 |
| Red Hat Enterprise Linux 8 | kernel-rt | Fixed | RHSA-2026:75746 | 05.10.2026 |
| Red Hat Enterprise Linux 8 | kernel | Fixed | RHSA-2026:75747 | 05.10.2026 |
| Red Hat Enterprise Linux 9 | kernel | Fixed | RHSA-2026:76739 | 08.10.2026 |
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Дополнительная информация
Статус:
EPSS
7.8 High
CVSS3
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: nvme: add missing SRCU grace period in error path nvme_alloc_ns() error path at out_unlink_ns removes ns from the namespace head siblings list with list_del_rcu(&ns->siblings) but does not wait for SRCU readers before freeing the namespace struct. Multipath code iterates the head->list under srcu_read_lock() in nvme_find_path() and nvme_mpath_revalidate_paths(), so a concurrent reader can still hold a reference to ns when kfree(ns) runs. The normal removal path in nvme_ns_remove() correctly calls synchronize_srcu(&ns->head->srcu) after list_del_rcu() to wait for in-progress readers. Add the same grace period in the error path.
In the Linux kernel, the following vulnerability has been resolved: nvme: add missing SRCU grace period in error path nvme_alloc_ns() error path at out_unlink_ns removes ns from the namespace head siblings list with list_del_rcu(&ns->siblings) but does not wait for SRCU readers before freeing the namespace struct. Multipath code iterates the head->list under srcu_read_lock() in nvme_find_path() and nvme_mpath_revalidate_paths(), so a concurrent reader can still hold a reference to ns when kfree(ns) runs. The normal removal path in nvme_ns_remove() correctly calls synchronize_srcu(&ns->head->srcu) after list_del_rcu() to wait for in-progress readers. Add the same grace period in the error path.
In the Linux kernel, the following vulnerability has been resolved: n ...
In the Linux kernel, the following vulnerability has been resolved: nvme: add missing SRCU grace period in error path nvme_alloc_ns() error path at out_unlink_ns removes ns from the namespace head siblings list with list_del_rcu(&ns->siblings) but does not wait for SRCU readers before freeing the namespace struct. Multipath code iterates the head->list under srcu_read_lock() in nvme_find_path() and nvme_mpath_revalidate_paths(), so a concurrent reader can still hold a reference to ns when kfree(ns) runs. The normal removal path in nvme_ns_remove() correctly calls synchronize_srcu(&ns->head->srcu) after list_del_rcu() to wait for in-progress readers. Add the same grace period in the error path.
EPSS
7.8 High
CVSS3