From 281393894af9cc3f9483204475014e89d728987c Mon Sep 17 00:00:00 2001 From: Steve French Date: Mon, 9 Dec 2019 19:47:10 -0600 Subject: smb3: fix refcount underflow warning on unmount when no directory leases Fix refcount underflow warning when unmounting to servers which didn't grant directory leases. [ 301.680095] refcount_t: underflow; use-after-free. [ 301.680192] WARNING: CPU: 1 PID: 3569 at lib/refcount.c:28 refcount_warn_saturate+0xb4/0xf3 ... [ 301.682139] Call Trace: [ 301.682240] close_shroot+0x97/0xda [cifs] [ 301.682351] SMB2_tdis+0x7c/0x176 [cifs] [ 301.682456] ? _get_xid+0x58/0x91 [cifs] [ 301.682563] cifs_put_tcon.part.0+0x99/0x202 [cifs] [ 301.682637] ? ida_free+0x99/0x10a [ 301.682727] ? cifs_umount+0x3d/0x9d [cifs] [ 301.682829] cifs_put_tlink+0x3a/0x50 [cifs] [ 301.682929] cifs_umount+0x44/0x9d [cifs] Fixes: 72e73c78c446 ("cifs: close the shared root handle on tree disconnect") Signed-off-by: Steve French Acked-by: Ronnie Sahlberg Reviewed-by: Aurelien Aptel Reviewed-by: Pavel Shilovsky Reported-and-tested-by: Arthur Marsh --- fs/cifs/smb2pdu.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c index 0ab6b1200288..d2658f51ff60 100644 --- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -1847,7 +1847,8 @@ SMB2_tdis(const unsigned int xid, struct cifs_tcon *tcon) if ((tcon->need_reconnect) || (tcon->ses->need_reconnect)) return 0; - close_shroot(&tcon->crfid); + if (tcon->crfid.is_valid) + close_shroot(&tcon->crfid); rc = smb2_plain_req_init(SMB2_TREE_DISCONNECT, tcon, (void **) &req, &total_len); -- cgit v1.2.3 From e0fc5b1153b81571d6ff80902a54c3eb13319b33 Mon Sep 17 00:00:00 2001 From: Steve French Date: Mon, 9 Dec 2019 22:34:10 -0600 Subject: SMB3: Fix crash in SMB2_open_init due to uninitialized field in compounding path Ran into an intermittent crash in SMB2_open_init+0x2f6/0x970 due to oparms.cifs_sb not being initialized when called from: smb2_compound_op+0x45d/0x1690 Zero the whole oparms struct in the compounding path before setting up the oparms so we don't risk any uninitialized fields. Fixes: fdef665ba44a ("smb3: fix mode passed in on create for modetosid mount option") Signed-off-by: Steve French Acked-by: Ronnie Sahlberg Reviewed-by: Pavel Shilovsky --- fs/cifs/smb2inode.c | 1 + 1 file changed, 1 insertion(+) diff --git a/fs/cifs/smb2inode.c b/fs/cifs/smb2inode.c index 18c7a33adceb..5ef5e97a6d13 100644 --- a/fs/cifs/smb2inode.c +++ b/fs/cifs/smb2inode.c @@ -95,6 +95,7 @@ smb2_compound_op(const unsigned int xid, struct cifs_tcon *tcon, goto finished; } + memset(&oparms, 0, sizeof(struct cifs_open_parms)); oparms.tcon = tcon; oparms.desired_access = desired_access; oparms.disposition = create_disposition; -- cgit v1.2.3 From d9191319358da13ee6a332fb9bf745f2181a612a Mon Sep 17 00:00:00 2001 From: Pavel Shilovsky Date: Tue, 10 Dec 2019 11:44:52 -0800 Subject: CIFS: Close cached root handle only if it has a lease SMB2_tdis() checks if a root handle is valid in order to decide whether it needs to close the handle or not. However if another thread has reference for the handle, it may end up with putting the reference twice. The extra reference that we want to put during the tree disconnect is the reference that has a directory lease. So, track the fact that we have a directory lease and close the handle only in that case. Signed-off-by: Pavel Shilovsky Reviewed-by: Ronnie Sahlberg Signed-off-by: Steve French --- fs/cifs/cifsglob.h | 2 +- fs/cifs/cifssmb.c | 3 +++ fs/cifs/smb2ops.c | 19 ++++++++++++++++++- fs/cifs/smb2pdu.c | 3 +-- fs/cifs/smb2proto.h | 2 ++ 5 files changed, 25 insertions(+), 4 deletions(-) diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h index fd0262ce5ad5..ce9bac756c2a 100644 --- a/fs/cifs/cifsglob.h +++ b/fs/cifs/cifsglob.h @@ -1061,7 +1061,7 @@ cap_unix(struct cifs_ses *ses) struct cached_fid { bool is_valid:1; /* Do we have a useable root fid */ bool file_all_info_is_valid:1; - + bool has_lease:1; struct kref refcount; struct cifs_fid *fid; struct mutex fid_mutex; diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c index 4f554f019a98..cc86a67225d1 100644 --- a/fs/cifs/cifssmb.c +++ b/fs/cifs/cifssmb.c @@ -42,6 +42,7 @@ #include "cifsproto.h" #include "cifs_unicode.h" #include "cifs_debug.h" +#include "smb2proto.h" #include "fscache.h" #include "smbdirect.h" #ifdef CONFIG_CIFS_DFS_UPCALL @@ -112,6 +113,8 @@ cifs_mark_open_files_invalid(struct cifs_tcon *tcon) mutex_lock(&tcon->crfid.fid_mutex); tcon->crfid.is_valid = false; + /* cached handle is not valid, so SMB2_CLOSE won't be sent below */ + close_shroot_lease_locked(&tcon->crfid); memset(tcon->crfid.fid, 0, sizeof(struct cifs_fid)); mutex_unlock(&tcon->crfid.fid_mutex); diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c index a5c96bc522cb..6250370c1170 100644 --- a/fs/cifs/smb2ops.c +++ b/fs/cifs/smb2ops.c @@ -616,6 +616,7 @@ smb2_close_cached_fid(struct kref *ref) cfid->fid->volatile_fid); cfid->is_valid = false; cfid->file_all_info_is_valid = false; + cfid->has_lease = false; } } @@ -626,13 +627,28 @@ void close_shroot(struct cached_fid *cfid) mutex_unlock(&cfid->fid_mutex); } +void close_shroot_lease_locked(struct cached_fid *cfid) +{ + if (cfid->has_lease) { + cfid->has_lease = false; + kref_put(&cfid->refcount, smb2_close_cached_fid); + } +} + +void close_shroot_lease(struct cached_fid *cfid) +{ + mutex_lock(&cfid->fid_mutex); + close_shroot_lease_locked(cfid); + mutex_unlock(&cfid->fid_mutex); +} + void smb2_cached_lease_break(struct work_struct *work) { struct cached_fid *cfid = container_of(work, struct cached_fid, lease_break); - close_shroot(cfid); + close_shroot_lease(cfid); } /* @@ -773,6 +789,7 @@ int open_shroot(unsigned int xid, struct cifs_tcon *tcon, struct cifs_fid *pfid) /* BB TBD check to see if oplock level check can be removed below */ if (o_rsp->OplockLevel == SMB2_OPLOCK_LEVEL_LEASE) { kref_get(&tcon->crfid.refcount); + tcon->crfid.has_lease = true; smb2_parse_contexts(server, o_rsp, &oparms.fid->epoch, oparms.fid->lease_key, &oplock, NULL); diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c index d2658f51ff60..9434f6dd8df3 100644 --- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -1847,8 +1847,7 @@ SMB2_tdis(const unsigned int xid, struct cifs_tcon *tcon) if ((tcon->need_reconnect) || (tcon->ses->need_reconnect)) return 0; - if (tcon->crfid.is_valid) - close_shroot(&tcon->crfid); + close_shroot_lease(&tcon->crfid); rc = smb2_plain_req_init(SMB2_TREE_DISCONNECT, tcon, (void **) &req, &total_len); diff --git a/fs/cifs/smb2proto.h b/fs/cifs/smb2proto.h index a18272c987fe..27d29f2eb6c8 100644 --- a/fs/cifs/smb2proto.h +++ b/fs/cifs/smb2proto.h @@ -70,6 +70,8 @@ extern int smb3_handle_read_data(struct TCP_Server_Info *server, extern int open_shroot(unsigned int xid, struct cifs_tcon *tcon, struct cifs_fid *pfid); extern void close_shroot(struct cached_fid *cfid); +extern void close_shroot_lease(struct cached_fid *cfid); +extern void close_shroot_lease_locked(struct cached_fid *cfid); extern void move_smb2_info_to_cifs(FILE_ALL_INFO *dst, struct smb2_file_all_info *src); extern int smb2_query_path_info(const unsigned int xid, struct cifs_tcon *tcon, -- cgit v1.2.3