Описание
In the Linux kernel, the following vulnerability has been resolved:
lockd: fix swapped arguments in nlmsvc_match_ip()
When releasing locks by server IP address via /proc/fs/nfsd/unlock_ip,
nlmsvc_unlock_all_by_ip() calls nlm_traverse_files() with the server
sockaddr as the opaque @data argument:
nlm_traverse_files(server_addr, nlmsvc_match_ip, NULL);
The match callback is later invoked from nlm_traverse_locks() as:
match(lockhost, host);
where the first argument is the nlm_host that owns the lock, and the
second argument is the @data that was originally passed down (here the
server sockaddr). This is the convention every other match callback
relies on (nlmsvc_mark_host(), nlmsvc_same_host(), nlmsvc_is_client()):
arg1 is the real nlm_host, arg2 is the caller-supplied reference value.
nlmsvc_match_ip() has had these two arguments reversed ever since the
unlock-by-IP feature was introduced in commit 4373ea84c84d ("lockd:
unlock lockd locks associated with a given server ip"):
return rpc_cmp_addr(nlm_srcaddr(host), datap);
Here @host is actually the server sockaddr, so nlm_srcaddr(host)
dereferences a struct sockaddr as a struct nlm_host and reads garbage
at the offset of h_srcaddr; meanwhile @datap is actually the lock
owner's nlm_host but is compared as a sockaddr. As a result the
comparison practically never matches and locks are not released for the
requested IP.
Swap the arguments so the lock owner's source address is compared
against the requested server address:
return rpc_cmp_addr(nlm_srcaddr(datap), (struct sockaddr *)host);
[ cel: fix the misleading typedef parameter names too ]
A flaw was found in the Linux kernel's lockd subsystem. A local privileged user can cause a Denial of Service (DoS) due to reversed function arguments when releasing locks by IP address. This issue causes the kernel to misinterpret memory structures, leading to invalid memory reads and preventing Network Lock Manager (NLM) locks from being released.
Отчет
This vulnerability is rated as Low impact because exploitation requires local administrative privileges to write to the NFS daemon administrative interface, limiting the blast radius on supported systems. In standard Red Hat Enterprise Linux environments, unprivileged users lack access to these control interfaces. The operational effect is largely restricted to lock cleanup failures for the specified network address rather than host compromise or privilege escalation.
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 | ||
| 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:
5.5 Medium
CVSS3
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: lockd: fix swapped arguments in nlmsvc_match_ip() When releasing locks by server IP address via /proc/fs/nfsd/unlock_ip, nlmsvc_unlock_all_by_ip() calls nlm_traverse_files() with the server sockaddr as the opaque @data argument: nlm_traverse_files(server_addr, nlmsvc_match_ip, NULL); The match callback is later invoked from nlm_traverse_locks() as: match(lockhost, host); where the first argument is the nlm_host that owns the lock, and the second argument is the @data that was originally passed down (here the server sockaddr). This is the convention every other match callback relies on (nlmsvc_mark_host(), nlmsvc_same_host(), nlmsvc_is_client()): arg1 is the real nlm_host, arg2 is the caller-supplied reference value. nlmsvc_match_ip() has had these two arguments reversed ever since the unlock-by-IP feature was introduced in commit 4373ea84c84d ("lockd: unlock lockd locks associated with a given server ip"): return r...
In the Linux kernel, the following vulnerability has been resolved: lockd: fix swapped arguments in nlmsvc_match_ip() When releasing locks by server IP address via /proc/fs/nfsd/unlock_ip, nlmsvc_unlock_all_by_ip() calls nlm_traverse_files() with the server sockaddr as the opaque @data argument: nlm_traverse_files(server_addr, nlmsvc_match_ip, NULL); The match callback is later invoked from nlm_traverse_locks() as: match(lockhost, host); where the first argument is the nlm_host that owns the lock, and the second argument is the @data that was originally passed down (here the server sockaddr). This is the convention every other match callback relies on (nlmsvc_mark_host(), nlmsvc_same_host(), nlmsvc_is_client()): arg1 is the real nlm_host, arg2 is the caller-supplied reference value. nlmsvc_match_ip() has had these two arguments reversed ever since the unlock-by-IP feature was introduced in commit 4373ea84c84d ("lockd: unlock lockd locks associated with a given server ip"):
In the Linux kernel, the following vulnerability has been resolved: l ...
In the Linux kernel, the following vulnerability has been resolved: lockd: fix swapped arguments in nlmsvc_match_ip() When releasing locks by server IP address via /proc/fs/nfsd/unlock_ip, nlmsvc_unlock_all_by_ip() calls nlm_traverse_files() with the server sockaddr as the opaque @data argument: nlm_traverse_files(server_addr, nlmsvc_match_ip, NULL); The match callback is later invoked from nlm_traverse_locks() as: match(lockhost, host); where the first argument is the nlm_host that owns the lock, and the second argument is the @data that was originally passed down (here the server sockaddr). This is the convention every other match callback relies on (nlmsvc_mark_host(), nlmsvc_same_host(), nlmsvc_is_client()): arg1 is the real nlm_host, arg2 is the caller-supplied reference value. nlmsvc_match_ip() has had these two arguments reversed ever since the unlock-by-IP feature was introduced in commit 4373ea84c84d ("lockd: unlock lockd locks associated with a given server ip"):...
5.5 Medium
CVSS3