From: Yang Erkun <yangerkun@huawei.com> hulk inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/IAUJJ4 CVE: NA -------------------------------- In the reclaim process, there may be a situation where all files are closed and the file system is unmounted, which will result in the release of nfs_server. This will trigger UAF in nfs4_put_open_state when the count of nfs4_state is decremented to zero, because the freed nfs_server will be accessed when evicting inode. Maintaining the nfs_server throughout the entire reclaim process by adding nfs_sb_active and nfs_sb_deactive to fix it. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Yang Erkun <yangerkun@huawei.com> Conflicts: fs/nfs/nfs4state.c [Commit e09b21df3b60("[Huawei] nfs: fix memory leak in error path of nfs4_do_reclaim") at hulk-5.10 add nfs4_free_state_owners in nfs4_do_reclaim to fix memory leak.] Signed-off-by: Li Lingfeng <lilingfeng3@huawei.com> --- fs/nfs/nfs4state.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c index c843917f8e2c..d9265c2eeb17 100644 --- a/fs/nfs/nfs4state.c +++ b/fs/nfs/nfs4state.c @@ -1875,6 +1875,12 @@ static int nfs4_do_reclaim(struct nfs_client *clp, const struct nfs4_state_recov continue; if (!atomic_inc_not_zero(&sp->so_count)) continue; + if (!(server->super && nfs_sb_active(server->super))) { + spin_unlock(&clp->cl_lock); + rcu_read_unlock(); + nfs4_put_state_owner(sp); + goto restart; + } spin_unlock(&clp->cl_lock); rcu_read_unlock(); @@ -1883,10 +1889,12 @@ static int nfs4_do_reclaim(struct nfs_client *clp, const struct nfs4_state_recov set_bit(ops->owner_flag_bit, &sp->so_flags); nfs4_put_state_owner(sp); status = nfs4_recovery_handle_error(clp, status); + nfs_sb_deactive(server->super); return (status != 0) ? status : -EAGAIN; } nfs4_put_state_owner(sp); + nfs_sb_deactive(server->super); goto restart; } spin_unlock(&clp->cl_lock); -- 2.31.1