From: Trond Myklebust Date: Sun, 10 Jan 2021 20:58:08 +0000 (-0500) Subject: NFS: nfs_igrab_and_active must first reference the superblock X-Git-Tag: v4.4.253~17 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=bd756f3238499558d48b919112f74496b4f6a286;p=thirdparty%2Fkernel%2Fstable.git NFS: nfs_igrab_and_active must first reference the superblock 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 Otherwise, we can end up with iput() calling superblock operations that are no longer valid or accessible.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 --- diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h index 578350fd96e11..7eeab683a81f8 100644 --- a/fs/nfs/internal.h +++ b/fs/nfs/internal.h @@ -534,12 +534,14 @@ extern int nfs41_walk_client_list(struct nfs_client *clp, 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)