From 427f5f83a3191cbf024c5aea6e5b601cdf88d895 Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Fri, 8 Jul 2022 14:27:09 -0400 Subject: [PATCH] NFSD: Ensure nf_inode is never dereferenced The documenting comment for struct nf_file states: /* * A representation of a file that has been opened by knfsd. These are hashed * in the hashtable by inode pointer value. Note that this object doesn't * hold a reference to the inode by itself, so the nf_inode pointer should * never be dereferenced, only used for comparison. */ Replace the two existing dereferences to make the comment always true. Reviewed-by: Jeff Layton Signed-off-by: Chuck Lever --- fs/nfsd/filecache.c | 5 ++--- fs/nfsd/filecache.h | 2 +- fs/nfsd/nfs4state.c | 2 +- 3 files changed, 4 insertions(+), 5 deletions(-) diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c index 58721fced7f3..57d06a2e94a2 100644 --- a/fs/nfsd/filecache.c +++ b/fs/nfsd/filecache.c @@ -228,12 +228,11 @@ nfsd_file_mark_put(struct nfsd_file_mark *nfm) } static struct nfsd_file_mark * -nfsd_file_mark_find_or_create(struct nfsd_file *nf) +nfsd_file_mark_find_or_create(struct nfsd_file *nf, struct inode *inode) { int err; struct fsnotify_mark *mark; struct nfsd_file_mark *nfm = NULL, *new; - struct inode *inode = nf->nf_inode; do { fsnotify_group_lock(nfsd_file_fsnotify_group); @@ -1144,7 +1143,7 @@ out_status: open_file: trace_nfsd_file_alloc(nf); - nf->nf_mark = nfsd_file_mark_find_or_create(nf); + nf->nf_mark = nfsd_file_mark_find_or_create(nf, key.inode); if (nf->nf_mark) { if (open) { status = nfsd_open_verified(rqstp, fhp, may_flags, diff --git a/fs/nfsd/filecache.h b/fs/nfsd/filecache.h index 28145f162892..8e8c0c47d67d 100644 --- a/fs/nfsd/filecache.h +++ b/fs/nfsd/filecache.h @@ -39,7 +39,7 @@ struct nfsd_file { #define NFSD_FILE_PENDING (1) #define NFSD_FILE_REFERENCED (2) unsigned long nf_flags; - struct inode *nf_inode; + struct inode *nf_inode; /* don't deref */ refcount_t nf_ref; unsigned char nf_may; struct nfsd_file_mark *nf_mark; diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 9d1a3e131c49..994bd11bafe0 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -2564,7 +2564,7 @@ static void nfs4_show_fname(struct seq_file *s, struct nfsd_file *f) static void nfs4_show_superblock(struct seq_file *s, struct nfsd_file *f) { - struct inode *inode = f->nf_inode; + struct inode *inode = file_inode(f->nf_file); seq_printf(s, "superblock: \"%02x:%02x:%ld\"", MAJOR(inode->i_sb->s_dev), -- 2.39.5