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| author | Ronnie Sahlberg <lsahlber@redhat.com> | 2019-03-28 11:20:02 +1000 |
|---|---|---|
| committer | Steve French <stfrench@microsoft.com> | 2019-04-01 14:33:30 -0500 |
| commit | 2f94a3125b8742b05a011d62b16f52eb8f9ebe1c (patch) | |
| tree | f32e1140c6857b8d6d751bb014fbe4c5793a9d57 /fs | |
| parent | 5e7a8ca319268a70a6c7c3c1fde5bea38e1e5539 (diff) | |
| download | linux-2f94a3125b8742b05a011d62b16f52eb8f9ebe1c.tar.gz linux-2f94a3125b8742b05a011d62b16f52eb8f9ebe1c.tar.bz2 linux-2f94a3125b8742b05a011d62b16f52eb8f9ebe1c.zip | |
cifs: fix kref underflow in close_shroot()
Fix a bug where we used to not initialize the cached fid structure at all
in open_shroot() if the open was successful but we did not get a lease.
This would leave the structure uninitialized and later when we close the handle
we would in close_shroot() try to kref_put() an uninitialized refcount.
Fix this by always initializing this structure if the open was successful
but only do the extra get() if we got a lease.
This extra get() is only used to hold the structure until we get a lease
break from the server at which point we will kref_put() it during lease
processing.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/cifs/smb2ops.c | 16 |
1 files changed, 7 insertions, 9 deletions
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c index 1022a3771e14..7cfafac255aa 100644 --- a/fs/cifs/smb2ops.c +++ b/fs/cifs/smb2ops.c @@ -717,20 +717,18 @@ int open_shroot(unsigned int xid, struct cifs_tcon *tcon, struct cifs_fid *pfid) oparms.fid->mid = le64_to_cpu(o_rsp->sync_hdr.MessageId); #endif /* CIFS_DEBUG2 */ - if (o_rsp->OplockLevel == SMB2_OPLOCK_LEVEL_LEASE) - oplock = smb2_parse_lease_state(server, o_rsp, - &oparms.fid->epoch, - oparms.fid->lease_key); - else - goto oshr_exit; - - memcpy(tcon->crfid.fid, pfid, sizeof(struct cifs_fid)); tcon->crfid.tcon = tcon; tcon->crfid.is_valid = true; kref_init(&tcon->crfid.refcount); - kref_get(&tcon->crfid.refcount); + if (o_rsp->OplockLevel == SMB2_OPLOCK_LEVEL_LEASE) { + kref_get(&tcon->crfid.refcount); + oplock = smb2_parse_lease_state(server, o_rsp, + &oparms.fid->epoch, + oparms.fid->lease_key); + } else + goto oshr_exit; qi_rsp = (struct smb2_query_info_rsp *)rsp_iov[1].iov_base; if (le32_to_cpu(qi_rsp->OutputBufferLength) < sizeof(struct smb2_file_all_info)) |