From: Chuck Lever <chuck.lever@xxxxxxxxxx> On Fri, 04 Oct 2024 18:04:03 -0400, Olga Kornievskaia wrote: > When multiple FREE_STATEIDs are sent for the same delegation stateid, > it can lead to a possible either use-after-tree 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 zerod counter. > > [...] Applied to nfsd-fixes for v6.12, thanks! [1/1] nfsd: fix possible badness in FREE_STATEID commit: c88c150a467fcb670a1608e2272beeee3e86df6e -- Chuck Lever