Description (CNA)
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.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected eec7620800081e27dbf8019ac2e66259f0d5bf6f before 69ed78b6b947c9257213164678b4edf17533093b; affected eec7620800081e27dbf8019ac2e66259f0d5bf6f before 00843074d9b84824552c9679d423d29500ca5de0; affected eec7620800081e27dbf8019ac2e66259f0d5bf6f before f7cb90ddc021747fc9abfd4cf5252d425fd34eec; affected eec7620800081e27dbf8019ac2e66259f0d5bf6f before 5e4627d3513e60accfce9d5f4c7fa95251ef93d6 |
| Linux / Linux | affected 6.10; unaffected 0 before 6.10; unaffected 6.12.109 through 6.12.*; unaffected 6.18.50 through 6.18.*; unaffected 7.2.4 through 7.2.*; unaffected 7.3 through * |
CWE
No CWE identifiers supplied.