From db93917456989d1b9b9b0c179ebff99306b28c67 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Mon, 22 Feb 2021 11:00:30 +0800 Subject: [PATCH] NFS: nfs_igrab_and_active must first reference the superblock stable inclusion from linux-4.19.169 commit df7adeee7477c865fecdd43b55aee6cca0e9bb0a -------------------------------- commit 896567ee7f17a8a736cda8a28cc987228410a2ac upstream. Before referencing the inode, we must ensure that the superblock can be referenced. Otherwise, we can end up with iput() calling superblock operations that are no longer valid or accessible. Fixes: ea7c38fef0b7 ("NFSv4: Ensure we reference the inode for return-on-close in delegreturn") Signed-off-by: Trond Myklebust Signed-off-by: Greg Kroah-Hartman Signed-off-by: Yang Yingliang Signed-off-by: Cheng Jian --- fs/nfs/internal.h | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h index 8357ff69962f..cc07189a501f 100644 --- a/fs/nfs/internal.h +++ b/fs/nfs/internal.h @@ -575,12 +575,14 @@ extern int nfs4_test_session_trunk(struct rpc_clnt *, static inline struct inode *nfs_igrab_and_active(struct inode *inode) { - inode = igrab(inode); - if (inode != NULL && !nfs_sb_active(inode->i_sb)) { - iput(inode); - inode = NULL; + struct super_block *sb = inode->i_sb; + + if (sb && nfs_sb_active(sb)) { + if (igrab(inode)) + return inode; + nfs_sb_deactive(sb); } - return inode; + return NULL; } static inline void nfs_iput_and_deactive(struct inode *inode) -- GitLab