nfsd: fix possible badness in FREE_STATEID
28Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 9.8epss 0.4%
exploitation probability
0.4%top 66% of all CVEs
observed exploitation
nono source reports it
In the Linux kernel, the following vulnerability has been resolved:
nfsd: fix possible badness in FREE_STATEID
When multiple FREE_STATEIDs are sent for the same delegation stateid,
it can lead to a possible either use-after-free or counter refcount
underflow errors.
In nfsd4_free_stateid() under the client lock we find a delegation
stateid, however the code drops the lock before calling nfs4_put_stid(),
that allows another FREE_STATE to find the stateid again. The first one
will proceed to then free the stateid which leads to either
use-after-free or decrementing already zeroed counter.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Affected products
Linux · Linux