mainline inclusion from mainline-v5.16-rc1 commit 576acc259146af848cec0940f573f7125a116b9f category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/18238 CVE: CVE-2026-74730 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- During umount, the session slot tables are freed. If there are outstanding FREE_STATEID tasks, a use-after-free and slab corruption can occur when rpc_exit_task calls rpc_call_done -> nfs41_sequence_done -> nfs4_sequence_process/nfs41_sequence_free_slot. Prevent that from happening by taking a reference on the nfs_client in nfs41_free_stateid and putting it in nfs41_free_stateid_release. Signed-off-by: Scott Mayhew <smayhew@redhat.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Zhou Minqiang <zhouminqiang2@huawei.com> --- fs/nfs/nfs4proc.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 4b3c614361bd..785ab1e49845 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -10120,6 +10120,10 @@ static void nfs41_free_stateid_done(struct rpc_task *task, void *calldata) static void nfs41_free_stateid_release(void *calldata) { + struct nfs_free_stateid_data *data = calldata; + struct nfs_client *clp = data->server->nfs_client; + + nfs_put_client(clp); kfree(calldata); } @@ -10156,6 +10160,10 @@ static int nfs41_free_stateid(struct nfs_server *server, }; struct nfs_free_stateid_data *data; struct rpc_task *task; + struct nfs_client *clp = server->nfs_client; + + if (!refcount_inc_not_zero(&clp->cl_count)) + return -EIO; nfs4_state_protect(server->nfs_client, NFS_SP4_MACH_CRED_STATEID, &task_setup.rpc_client, &msg); -- 2.52.0