diff options
| author | J. Bruce Fields <bfields@redhat.com> | 2020-07-15 13:31:36 -0400 |
|---|---|---|
| committer | J. Bruce Fields <bfields@redhat.com> | 2020-07-22 16:47:14 -0400 |
| commit | 9affa435817711861d774f5626c393c80f16d044 (patch) | |
| tree | cdbc309d8b515f478f1595b617911b84141bc028 /fs | |
| parent | becd2014923ff259b8155df58199f605dd50cb8f (diff) | |
nfsd4: fix NULL dereference in nfsd/clients display code
We hold the cl_lock here, and that's enough to keep stateid's from going
away, but it's not enough to prevent the files they point to from going
away. Take fi_lock and a reference and check for NULL, as we do in
other code.
Reported-by: NeilBrown <neilb@suse.de>
Fixes: 78599c42ae3c ("nfsd4: add file to display list of client's opens")
Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/nfsd/nfs4state.c | 20 |
1 files changed, 19 insertions, 1 deletions
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index cce2510b2cca..c9056316a0b3 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -507,6 +507,17 @@ find_any_file(struct nfs4_file *f) return ret; } +static struct nfsd_file *find_deleg_file(struct nfs4_file *f) +{ + struct nfsd_file *ret = NULL; + + spin_lock(&f->fi_lock); + if (f->fi_deleg_file) + ret = nfsd_file_get(f->fi_deleg_file); + spin_unlock(&f->fi_lock); + return ret; +} + static atomic_long_t num_delegations; unsigned long max_delegations; @@ -2444,6 +2455,8 @@ static int nfs4_show_open(struct seq_file *s, struct nfs4_stid *st) oo = ols->st_stateowner; nf = st->sc_file; file = find_any_file(nf); + if (!file) + return 0; seq_printf(s, "- "); nfs4_show_stateid(s, &st->sc_stateid); @@ -2481,6 +2494,8 @@ static int nfs4_show_lock(struct seq_file *s, struct nfs4_stid *st) oo = ols->st_stateowner; nf = st->sc_file; file = find_any_file(nf); + if (!file) + return 0; seq_printf(s, "- "); nfs4_show_stateid(s, &st->sc_stateid); @@ -2513,7 +2528,9 @@ static int nfs4_show_deleg(struct seq_file *s, struct nfs4_stid *st) ds = delegstateid(st); nf = st->sc_file; - file = nf->fi_deleg_file; + file = find_deleg_file(nf); + if (!file) + return 0; seq_printf(s, "- "); nfs4_show_stateid(s, &st->sc_stateid); @@ -2529,6 +2546,7 @@ static int nfs4_show_deleg(struct seq_file *s, struct nfs4_stid *st) seq_printf(s, ", "); nfs4_show_fname(s, file); seq_printf(s, " }\n"); + nfsd_file_put(file); return 0; } |