Affected: Alpaquita:25: linux-lts, Alpaquita:stream: linux-lts

In the Linux kernel, the following vulnerability has been resolved:

SUNRPC: Check svc pool percpu counter allocation

__svc_create() initializes three per-pool percpu_counter stats and ignores every return value. On SMP, percpu_counter_init() fails when __alloc_percpu_gfp() cannot satisfy the allocation, leaving the failed counter with fbc->counters == NULL and its embedded raw_spinlock_t, list_head, and count never initialized. __svc_create() returns the half-constructed svc_serv to nfsd, lockd, or the NFS callback service anyway.

Once that service is live, the hot-path increments in svc_xprt_enqueue(), svc_handle_xprt(), and svc_pool_wake_idle_thread() reach a counter whose backing pointer is NULL. The pointer is a per-cpu offset, so the access does not fault: it resolves to offset zero of the current CPU's per-cpu area and silently corrupts whatever variable lives there. A /proc/fs/nfsd/pool_stats read walks the same NULL per-cpu storage and returns garbage, and on CONFIG_DEBUG_SPINLOCK or lockdep it splats on the never-initialized lock.

Creating the broken service requires a percpu allocation failure during RPC server startup, so it is reachable only by a local administrator under memory pressure or fault injection; a remote peer cannot induce the bad state on its own.

Check each percpu_counter_init() return value in __svc_create() and fail when an allocation fails, unwinding the counters already set up in the current pool and in every pool initialized before it. A d…

In the Linux kernel, the following vulnerability has been resolved:

SUNRPC: Check svc pool percpu counter allocation

__svc_create() initializes three per-pool percpu_counter stats and ignores every return value. On SMP, percpu_counter_init() fails when __alloc_percpu_gfp() cannot satisfy the allocation, leaving the failed counter with fbc->counters == NULL and its embedded raw_spinlock_t, list_head, and count never initialized. __svc_create() returns the half-constructed svc_serv to nfsd, lockd, or the NFS callback service anyway.

Once that service is live, the hot-path increments in svc_xprt_enqueue(), svc_handle_xprt(), and svc_pool_wake_idle_thread() reach a counter whose backing pointer is NULL. The pointer is a per-cpu offset, so the access does not fault: it resolves to offset zero of the current CPU's per-cpu area and silently corrupts whatever variable lives there. A /proc/fs/nfsd/pool_stats read walks the same NULL per-cpu storage and returns garbage, and on CONFIG_DEBUG_SPINLOCK or lockdep it splats on the never-initialized lock.

Creating the broken service requires a percpu allocation failure during RPC server startup, so it is reachable only by a local administrator under memory pressure or fault injection; a remote peer cannot induce the bad state on its own.

Check each percpu_counter_init() return value in __svc_create() and fail when an allocation fails, unwinding the counters already set up in the current pool and in every pool initialized before it. A d…

kernel-devel-7.2.7-1.1 on GA media

Affected: Ubuntu:16.04:LTS: linux-hwe-edge, Ubuntu:18.04:LTS: linux-aws-5.0, Ubuntu:18.04:LTS: linux-aws-5.3, Ubuntu:18.04:LTS: linux-azure, Ubuntu:18.04:LTS: linux-azure-5.3, Ubuntu:18.04:LTS: linux-azure-edge, Ubuntu:18.04:LTS: linux-gcp, Ubuntu:18.04:LTS: linux-gcp-5.3, Ubuntu:18.04:LTS: linux-gke-4.15, Ubuntu:18.04:LTS: linux-gke-5.4 and 154 more

In the Linux kernel, the following vulnerability has been resolved: SUNRPC: Check svc pool percpu counter allocation __svc_create() initializes three per-pool percpu_counter stats and ignores every return value. On SMP, percpu_counter_init() fails when __alloc_percpu_gfp() cannot satisfy the allocation, leaving the failed counter with fbc->counters == NULL and its embedded raw_spinlock_t, list_head, and count never initialized. __svc_create() returns the half-constructed svc_serv to nfsd, lockd, or the NFS callback service anyway. Once that service is live, the hot-path increments in svc_xprt_enqueue(), svc_handle_xprt(), and svc_pool_wake_idle_thread() reach a counter whose backing pointer is NULL. The pointer is a per-cpu offset, so the access does not fault: it resolves to offset zero of the current CPU's per-cpu area and silently corrupts whatever variable lives there. A /proc/fs/nfsd/pool_stats read walks the same NULL per-cpu storage and returns garbage, and on CONFIG_DEBUG_SPINLOCK or lockdep it splats on the never-initialized lock. Creating the broken service requires a percpu allocation failure during RPC server startup, so it is reachable only by a local administrator under memory pressure or fault injection; a remote peer cannot induce the bad state on its own. Check each percpu_counter_init() return value in __svc_create() and fail when an allocation fails, unwinding the counters already set up in the current pool and in every pool initialized before it. A discre…

Ein Angreifer kann mehrere Schwachstellen im Linux Kernel ausnutzen, um Sicherheitsmaßnahmen zu umgehen, Daten oder den Systemzustand zu manipulieren, Denial-of-Service-Zustände herbeizuführen oder andere, nicht näher spezifizierte Angriffe durchzuführen.