Описание
In the Linux kernel, the following vulnerability has been resolved:
nfsd: drop the stateid, not the stateowner, on seqid_op replay retry
In nfs4_preprocess_seqid_op() the stateid is obtained from
nfsd4_lookup_stateid(), which holds a reference on the nfs4_stid
(sc_count) but takes no reference on the stateowner. openlockstateid()
merely casts that stid and likewise takes no reference.
When nfsd4_cstate_assign_replay() returns -EAGAIN (the replay owner is
being torn down, RP_UNHASHED) it has not taken a stateowner reference on
that path. The error handling nevertheless called
nfs4_put_stateowner(stp->st_stateowner), dropping an so_count reference
the function never acquired -- risking a stateowner refcount underflow and
use-after-free -- while leaking the sc_count reference held on the stid.
The leaked stid reference can also stall a concurrent
nfsd4_close_open_stateid() waiting for sc_count to drop.
Drop the reference actually held -- the stid -- before retrying. The
stateowner stays alive through the reference held by the stid. This mirrors
the open path in nfsd4_process_open1(), where the put balances a reference
that path explicitly holds on the stateowner.
A flaw was found in the Linux kernel's nfsd component. During a seqid_op replay retry, the system incorrectly handles reference counts for stateowners, leading to a reference count underflow and a use-after-free vulnerability. This issue could allow an attacker to potentially cause a denial of service or execute arbitrary code.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat OpenShift Container Platform 4 | openshift/ose-rhel-coreos-8 | Affected | ||
| Red Hat OpenShift Container Platform 4 | openshift/ose-rhel-coreos-9 | Affected |
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Дополнительная информация
Статус:
EPSS
5.3 Medium
CVSS3
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: nfsd: drop the stateid, not the stateowner, on seqid_op replay retry In nfs4_preprocess_seqid_op() the stateid is obtained from nfsd4_lookup_stateid(), which holds a reference on the nfs4_stid (sc_count) but takes no reference on the stateowner. openlockstateid() merely casts that stid and likewise takes no reference. When nfsd4_cstate_assign_replay() returns -EAGAIN (the replay owner is being torn down, RP_UNHASHED) it has not taken a stateowner reference on that path. The error handling nevertheless called nfs4_put_stateowner(stp->st_stateowner), dropping an so_count reference the function never acquired -- risking a stateowner refcount underflow and use-after-free -- while leaking the sc_count reference held on the stid. The leaked stid reference can also stall a concurrent nfsd4_close_open_stateid() waiting for sc_count to drop. Drop the reference actually held -- the stid -- before retrying. The stateowner stay...
In the Linux kernel, the following vulnerability has been resolved: nfsd: drop the stateid, not the stateowner, on seqid_op replay retry In nfs4_preprocess_seqid_op() the stateid is obtained from nfsd4_lookup_stateid(), which holds a reference on the nfs4_stid (sc_count) but takes no reference on the stateowner. openlockstateid() merely casts that stid and likewise takes no reference. When nfsd4_cstate_assign_replay() returns -EAGAIN (the replay owner is being torn down, RP_UNHASHED) it has not taken a stateowner reference on that path. The error handling nevertheless called nfs4_put_stateowner(stp->st_stateowner), dropping an so_count reference the function never acquired -- risking a stateowner refcount underflow and use-after-free -- while leaking the sc_count reference held on the stid. The leaked stid reference can also stall a concurrent nfsd4_close_open_stateid() waiting for sc_count to drop. Drop the reference actually held -- the stid -- before retrying. The stateowner sta
In the Linux kernel, the following vulnerability has been resolved: n ...
In the Linux kernel, the following vulnerability has been resolved: nfsd: drop the stateid, not the stateowner, on seqid_op replay retry In nfs4_preprocess_seqid_op() the stateid is obtained from nfsd4_lookup_stateid(), which holds a reference on the nfs4_stid (sc_count) but takes no reference on the stateowner. openlockstateid() merely casts that stid and likewise takes no reference. When nfsd4_cstate_assign_replay() returns -EAGAIN (the replay owner is being torn down, RP_UNHASHED) it has not taken a stateowner reference on that path. The error handling nevertheless called nfs4_put_stateowner(stp->st_stateowner), dropping an so_count reference the function never acquired -- risking a stateowner refcount underflow and use-after-free -- while leaking the sc_count reference held on the stid. The leaked stid reference can also stall a concurrent nfsd4_close_open_stateid() waiting for sc_count to drop. Drop the reference actually held -- the stid -- before retrying. The stateowner ...
EPSS
5.3 Medium
CVSS3