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| author | Olga Kornievskaia <okorniev@redhat.com> | 2024-08-23 18:51:08 +0300 |
|---|---|---|
| committer | Chuck Lever <chuck.lever@oracle.com> | 2024-08-23 19:25:46 +0300 |
| commit | a204501e1743d695ca2930ed25a2be9f8ced96d3 (patch) | |
| tree | 7a59d18c335d0fb4babc37e0237f4f14048cc84d /fs/nfsd | |
| parent | f58bab6fd4063913bd8321e99874b8239e9ba726 (diff) | |
| download | linux-a204501e1743d695ca2930ed25a2be9f8ced96d3.tar.xz | |
nfsd: prevent panic for nfsv4.0 closed files in nfs4_show_open
Prior to commit 3f29cc82a84c ("nfsd: split sc_status out of
sc_type") states_show() relied on sc_type field to be of valid
type before calling into a subfunction to show content of a
particular stateid. From that commit, we split the validity of
the stateid into sc_status and no longer changed sc_type to 0
while unhashing the stateid. This resulted in kernel oopsing
for nfsv4.0 opens that stay around and in nfs4_show_open()
would derefence sc_file which was NULL.
Instead, for closed open stateids forgo displaying information
that relies of having a valid sc_file.
To reproduce: mount the server with 4.0, read and close
a file and then on the server cat /proc/fs/nfsd/clients/2/states
[ 513.590804] Call trace:
[ 513.590925] _raw_spin_lock+0xcc/0x160
[ 513.591119] nfs4_show_open+0x78/0x2c0 [nfsd]
[ 513.591412] states_show+0x44c/0x488 [nfsd]
[ 513.591681] seq_read_iter+0x5d8/0x760
[ 513.591896] seq_read+0x188/0x208
[ 513.592075] vfs_read+0x148/0x470
[ 513.592241] ksys_read+0xcc/0x178
Fixes: 3f29cc82a84c ("nfsd: split sc_status out of sc_type")
Signed-off-by: Olga Kornievskaia <okorniev@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Diffstat (limited to 'fs/nfsd')
| -rw-r--r-- | fs/nfsd/nfs4state.c | 21 |
1 files changed, 12 insertions, 9 deletions
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index a20c2c9d7d45..dafff707e23a 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -2789,15 +2789,18 @@ static int nfs4_show_open(struct seq_file *s, struct nfs4_stid *st) deny & NFS4_SHARE_ACCESS_READ ? "r" : "-", deny & NFS4_SHARE_ACCESS_WRITE ? "w" : "-"); - spin_lock(&nf->fi_lock); - file = find_any_file_locked(nf); - if (file) { - nfs4_show_superblock(s, file); - seq_puts(s, ", "); - nfs4_show_fname(s, file); - seq_puts(s, ", "); - } - spin_unlock(&nf->fi_lock); + if (nf) { + spin_lock(&nf->fi_lock); + file = find_any_file_locked(nf); + if (file) { + nfs4_show_superblock(s, file); + seq_puts(s, ", "); + nfs4_show_fname(s, file); + seq_puts(s, ", "); + } + spin_unlock(&nf->fi_lock); + } else + seq_puts(s, "closed, "); nfs4_show_owner(s, oo); if (st->sc_status & SC_STATUS_ADMIN_REVOKED) seq_puts(s, ", admin-revoked"); |