6.10-stable review patch. If anyone has any objections, please let me know.
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From: Olga Kornievskaia okorniev@redhat.com
[ Upstream commit a204501e1743d695ca2930ed25a2be9f8ced96d3 ]
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 Signed-off-by: Sasha Levin sashal@kernel.org --- fs/nfsd/nfs4state.c | 21 ++++++++++++--------- 1 file changed, 12 insertions(+), 9 deletions(-)
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index a20c2c9d7d457..dafff707e23a4 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");