| Message ID | 20230228220155.23394-1-pc@manguebit.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v2,1/2] cifs: improve checking of DFS links over STATUS_OBJECT_NAME_INVALID | expand |
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com> On Wed, 1 Mar 2023 at 08:15, Paulo Alcantara <pc@manguebit.com> wrote: > > Do not map STATUS_OBJECT_NAME_INVALID to -EREMOTE under non-DFS > shares, or 'nodfs' mounts or CONFIG_CIFS_DFS_UPCALL=n builds. > Otherwise, in the slow path, get a referral to figure out whether it > is an actual DFS link. > > This could be simply reproduced under a non-DFS share by running the > following > > $ mount.cifs //srv/share /mnt -o ... > $ cat /mnt/$(printf '\U110000') > cat: '/mnt/'$'\364\220\200\200': Object is remote > > Fixes: c877ce47e137 ("cifs: reduce roundtrips on create/qinfo requests") > Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com> > --- > v1 -> v2: fixed mem leak on PTR_ERR(ref_path) != -EINVAL > > fs/cifs/cifsproto.h | 20 ++++++++++---- > fs/cifs/misc.c | 67 +++++++++++++++++++++++++++++++++++++++++++++ > fs/cifs/smb2inode.c | 21 +++++++------- > fs/cifs/smb2ops.c | 23 +++++++++------- > 4 files changed, 106 insertions(+), 25 deletions(-) > > diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h > index b7a36ebd0f2f..20a2f0f3f682 100644 > --- a/fs/cifs/cifsproto.h > +++ b/fs/cifs/cifsproto.h > @@ -667,11 +667,21 @@ static inline int get_dfs_path(const unsigned int xid, struct cifs_ses *ses, > int match_target_ip(struct TCP_Server_Info *server, > const char *share, size_t share_len, > bool *result); > - > -int cifs_dfs_query_info_nonascii_quirk(const unsigned int xid, > - struct cifs_tcon *tcon, > - struct cifs_sb_info *cifs_sb, > - const char *dfs_link_path); > +int cifs_inval_name_dfs_link_error(const unsigned int xid, > + struct cifs_tcon *tcon, > + struct cifs_sb_info *cifs_sb, > + const char *full_path, > + bool *islink); > +#else > +static inline int cifs_inval_name_dfs_link_error(const unsigned int xid, > + struct cifs_tcon *tcon, > + struct cifs_sb_info *cifs_sb, > + const char *full_path, > + bool *islink) > +{ > + *islink = false; > + return 0; > +} > #endif > > static inline int cifs_create_options(struct cifs_sb_info *cifs_sb, int options) > diff --git a/fs/cifs/misc.c b/fs/cifs/misc.c > index 2905734eb289..0c6c1fc8dae9 100644 > --- a/fs/cifs/misc.c > +++ b/fs/cifs/misc.c > @@ -21,6 +21,7 @@ > #include "cifsfs.h" > #ifdef CONFIG_CIFS_DFS_UPCALL > #include "dns_resolve.h" > +#include "dfs_cache.h" > #endif > #include "fs_context.h" > #include "cached_dir.h" > @@ -1198,4 +1199,70 @@ int cifs_update_super_prepath(struct cifs_sb_info *cifs_sb, char *prefix) > cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH; > return 0; > } > + > +/* > + * Handle weird Windows SMB server behaviour. It responds with > + * STATUS_OBJECT_NAME_INVALID code to SMB2 QUERY_INFO request for > + * "\<server>\<dfsname>\<linkpath>" DFS reference, where <dfsname> contains > + * non-ASCII unicode symbols. > + */ > +int cifs_inval_name_dfs_link_error(const unsigned int xid, > + struct cifs_tcon *tcon, > + struct cifs_sb_info *cifs_sb, > + const char *full_path, > + bool *islink) > +{ > + struct cifs_ses *ses = tcon->ses; > + size_t len; > + char *path; > + char *ref_path; > + > + *islink = false; > + > + /* > + * Fast path - skip check when @full_path doesn't have a prefix path to > + * look up or tcon is not DFS. > + */ > + if (strlen(full_path) < 2 || !cifs_sb || > + (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS) || > + !is_tcon_dfs(tcon) || !ses->server->origin_fullpath) > + return 0; > + > + /* > + * Slow path - tcon is DFS and @full_path has prefix path, so attempt > + * to get a referral to figure out whether it is an DFS link. > + */ > + len = strnlen(tcon->tree_name, MAX_TREE_SIZE + 1) + strlen(full_path) + 1; > + path = kmalloc(len, GFP_KERNEL); > + if (!path) > + return -ENOMEM; > + > + scnprintf(path, len, "%s%s", tcon->tree_name, full_path); > + ref_path = dfs_cache_canonical_path(path + 1, cifs_sb->local_nls, > + cifs_remap(cifs_sb)); > + kfree(path); > + > + if (IS_ERR(ref_path)) { > + if (PTR_ERR(ref_path) != -EINVAL) > + return PTR_ERR(ref_path); > + } else { > + struct dfs_info3_param *refs = NULL; > + int num_refs = 0; > + > + /* > + * XXX: we are not using dfs_cache_find() here because we might > + * end filling all the DFS cache and thus potentially > + * removing cached DFS targets that the client would eventually > + * need during failover. > + */ > + if (ses->server->ops->get_dfs_refer && > + !ses->server->ops->get_dfs_refer(xid, ses, ref_path, &refs, > + &num_refs, cifs_sb->local_nls, > + cifs_remap(cifs_sb))) > + *islink = refs[0].server_type == DFS_TYPE_LINK; > + free_dfs_info_array(refs, num_refs); > + kfree(ref_path); > + } > + return 0; > +} > #endif > diff --git a/fs/cifs/smb2inode.c b/fs/cifs/smb2inode.c > index 37b4cd59245d..9b956294e864 100644 > --- a/fs/cifs/smb2inode.c > +++ b/fs/cifs/smb2inode.c > @@ -527,12 +527,13 @@ int smb2_query_path_info(const unsigned int xid, struct cifs_tcon *tcon, > struct cifs_sb_info *cifs_sb, const char *full_path, > struct cifs_open_info_data *data, bool *adjust_tz, bool *reparse) > { > - int rc; > __u32 create_options = 0; > struct cifsFileInfo *cfile; > struct cached_fid *cfid = NULL; > struct kvec err_iov[3] = {}; > int err_buftype[3] = {}; > + bool islink; > + int rc, rc2; > > *adjust_tz = false; > *reparse = false; > @@ -580,15 +581,15 @@ int smb2_query_path_info(const unsigned int xid, struct cifs_tcon *tcon, > SMB2_OP_QUERY_INFO, cfile, NULL, NULL, > NULL, NULL); > goto out; > - } else if (rc != -EREMOTE && IS_ENABLED(CONFIG_CIFS_DFS_UPCALL) && > - hdr->Status == STATUS_OBJECT_NAME_INVALID) { > - /* > - * Handle weird Windows SMB server behaviour. It responds with > - * STATUS_OBJECT_NAME_INVALID code to SMB2 QUERY_INFO request > - * for "\<server>\<dfsname>\<linkpath>" DFS reference, > - * where <dfsname> contains non-ASCII unicode symbols. > - */ > - rc = -EREMOTE; > + } else if (rc != -EREMOTE && hdr->Status == STATUS_OBJECT_NAME_INVALID) { > + rc2 = cifs_inval_name_dfs_link_error(xid, tcon, cifs_sb, > + full_path, &islink); > + if (rc2) { > + rc = rc2; > + goto out; > + } > + if (islink) > + rc = -EREMOTE; > } > if (rc == -EREMOTE && IS_ENABLED(CONFIG_CIFS_DFS_UPCALL) && cifs_sb && > (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS)) > diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c > index f79b075f2992..6dfb865ee9d7 100644 > --- a/fs/cifs/smb2ops.c > +++ b/fs/cifs/smb2ops.c > @@ -796,7 +796,6 @@ static int > smb2_is_path_accessible(const unsigned int xid, struct cifs_tcon *tcon, > struct cifs_sb_info *cifs_sb, const char *full_path) > { > - int rc; > __le16 *utf16_path; > __u8 oplock = SMB2_OPLOCK_LEVEL_NONE; > int err_buftype = CIFS_NO_BUFFER; > @@ -804,6 +803,8 @@ smb2_is_path_accessible(const unsigned int xid, struct cifs_tcon *tcon, > struct kvec err_iov = {}; > struct cifs_fid fid; > struct cached_fid *cfid; > + bool islink; > + int rc, rc2; > > rc = open_cached_dir(xid, tcon, full_path, cifs_sb, true, &cfid); > if (!rc) { > @@ -833,15 +834,17 @@ smb2_is_path_accessible(const unsigned int xid, struct cifs_tcon *tcon, > > if (unlikely(!hdr || err_buftype == CIFS_NO_BUFFER)) > goto out; > - /* > - * Handle weird Windows SMB server behaviour. It responds with > - * STATUS_OBJECT_NAME_INVALID code to SMB2 QUERY_INFO request > - * for "\<server>\<dfsname>\<linkpath>" DFS reference, > - * where <dfsname> contains non-ASCII unicode symbols. > - */ > - if (rc != -EREMOTE && IS_ENABLED(CONFIG_CIFS_DFS_UPCALL) && > - hdr->Status == STATUS_OBJECT_NAME_INVALID) > - rc = -EREMOTE; > + > + if (rc != -EREMOTE && hdr->Status == STATUS_OBJECT_NAME_INVALID) { > + rc2 = cifs_inval_name_dfs_link_error(xid, tcon, cifs_sb, > + full_path, &islink); > + if (rc2) { > + rc = rc2; > + goto out; > + } > + if (islink) > + rc = -EREMOTE; > + } > if (rc == -EREMOTE && IS_ENABLED(CONFIG_CIFS_DFS_UPCALL) && cifs_sb && > (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS)) > rc = -EOPNOTSUPP; > -- > 2.39.2 >
updated to add RB tag and added: CC: stable@vger.kernel.org # 6.2 On Tue, Feb 28, 2023 at 4:21 PM ronnie sahlberg <ronniesahlberg@gmail.com> wrote: > > Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com> > > On Wed, 1 Mar 2023 at 08:15, Paulo Alcantara <pc@manguebit.com> wrote: > > > > Do not map STATUS_OBJECT_NAME_INVALID to -EREMOTE under non-DFS > > shares, or 'nodfs' mounts or CONFIG_CIFS_DFS_UPCALL=n builds. > > Otherwise, in the slow path, get a referral to figure out whether it > > is an actual DFS link. > > > > This could be simply reproduced under a non-DFS share by running the > > following > > > > $ mount.cifs //srv/share /mnt -o ... > > $ cat /mnt/$(printf '\U110000') > > cat: '/mnt/'$'\364\220\200\200': Object is remote > > > > Fixes: c877ce47e137 ("cifs: reduce roundtrips on create/qinfo requests") > > Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com> > > --- > > v1 -> v2: fixed mem leak on PTR_ERR(ref_path) != -EINVAL > > > > fs/cifs/cifsproto.h | 20 ++++++++++---- > > fs/cifs/misc.c | 67 +++++++++++++++++++++++++++++++++++++++++++++ > > fs/cifs/smb2inode.c | 21 +++++++------- > > fs/cifs/smb2ops.c | 23 +++++++++------- > > 4 files changed, 106 insertions(+), 25 deletions(-) > > > > diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h > > index b7a36ebd0f2f..20a2f0f3f682 100644 > > --- a/fs/cifs/cifsproto.h > > +++ b/fs/cifs/cifsproto.h > > @@ -667,11 +667,21 @@ static inline int get_dfs_path(const unsigned int xid, struct cifs_ses *ses, > > int match_target_ip(struct TCP_Server_Info *server, > > const char *share, size_t share_len, > > bool *result); > > - > > -int cifs_dfs_query_info_nonascii_quirk(const unsigned int xid, > > - struct cifs_tcon *tcon, > > - struct cifs_sb_info *cifs_sb, > > - const char *dfs_link_path); > > +int cifs_inval_name_dfs_link_error(const unsigned int xid, > > + struct cifs_tcon *tcon, > > + struct cifs_sb_info *cifs_sb, > > + const char *full_path, > > + bool *islink); > > +#else > > +static inline int cifs_inval_name_dfs_link_error(const unsigned int xid, > > + struct cifs_tcon *tcon, > > + struct cifs_sb_info *cifs_sb, > > + const char *full_path, > > + bool *islink) > > +{ > > + *islink = false; > > + return 0; > > +} > > #endif > > > > static inline int cifs_create_options(struct cifs_sb_info *cifs_sb, int options) > > diff --git a/fs/cifs/misc.c b/fs/cifs/misc.c > > index 2905734eb289..0c6c1fc8dae9 100644 > > --- a/fs/cifs/misc.c > > +++ b/fs/cifs/misc.c > > @@ -21,6 +21,7 @@ > > #include "cifsfs.h" > > #ifdef CONFIG_CIFS_DFS_UPCALL > > #include "dns_resolve.h" > > +#include "dfs_cache.h" > > #endif > > #include "fs_context.h" > > #include "cached_dir.h" > > @@ -1198,4 +1199,70 @@ int cifs_update_super_prepath(struct cifs_sb_info *cifs_sb, char *prefix) > > cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH; > > return 0; > > } > > + > > +/* > > + * Handle weird Windows SMB server behaviour. It responds with > > + * STATUS_OBJECT_NAME_INVALID code to SMB2 QUERY_INFO request for > > + * "\<server>\<dfsname>\<linkpath>" DFS reference, where <dfsname> contains > > + * non-ASCII unicode symbols. > > + */ > > +int cifs_inval_name_dfs_link_error(const unsigned int xid, > > + struct cifs_tcon *tcon, > > + struct cifs_sb_info *cifs_sb, > > + const char *full_path, > > + bool *islink) > > +{ > > + struct cifs_ses *ses = tcon->ses; > > + size_t len; > > + char *path; > > + char *ref_path; > > + > > + *islink = false; > > + > > + /* > > + * Fast path - skip check when @full_path doesn't have a prefix path to > > + * look up or tcon is not DFS. > > + */ > > + if (strlen(full_path) < 2 || !cifs_sb || > > + (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS) || > > + !is_tcon_dfs(tcon) || !ses->server->origin_fullpath) > > + return 0; > > + > > + /* > > + * Slow path - tcon is DFS and @full_path has prefix path, so attempt > > + * to get a referral to figure out whether it is an DFS link. > > + */ > > + len = strnlen(tcon->tree_name, MAX_TREE_SIZE + 1) + strlen(full_path) + 1; > > + path = kmalloc(len, GFP_KERNEL); > > + if (!path) > > + return -ENOMEM; > > + > > + scnprintf(path, len, "%s%s", tcon->tree_name, full_path); > > + ref_path = dfs_cache_canonical_path(path + 1, cifs_sb->local_nls, > > + cifs_remap(cifs_sb)); > > + kfree(path); > > + > > + if (IS_ERR(ref_path)) { > > + if (PTR_ERR(ref_path) != -EINVAL) > > + return PTR_ERR(ref_path); > > + } else { > > + struct dfs_info3_param *refs = NULL; > > + int num_refs = 0; > > + > > + /* > > + * XXX: we are not using dfs_cache_find() here because we might > > + * end filling all the DFS cache and thus potentially > > + * removing cached DFS targets that the client would eventually > > + * need during failover. > > + */ > > + if (ses->server->ops->get_dfs_refer && > > + !ses->server->ops->get_dfs_refer(xid, ses, ref_path, &refs, > > + &num_refs, cifs_sb->local_nls, > > + cifs_remap(cifs_sb))) > > + *islink = refs[0].server_type == DFS_TYPE_LINK; > > + free_dfs_info_array(refs, num_refs); > > + kfree(ref_path); > > + } > > + return 0; > > +} > > #endif > > diff --git a/fs/cifs/smb2inode.c b/fs/cifs/smb2inode.c > > index 37b4cd59245d..9b956294e864 100644 > > --- a/fs/cifs/smb2inode.c > > +++ b/fs/cifs/smb2inode.c > > @@ -527,12 +527,13 @@ int smb2_query_path_info(const unsigned int xid, struct cifs_tcon *tcon, > > struct cifs_sb_info *cifs_sb, const char *full_path, > > struct cifs_open_info_data *data, bool *adjust_tz, bool *reparse) > > { > > - int rc; > > __u32 create_options = 0; > > struct cifsFileInfo *cfile; > > struct cached_fid *cfid = NULL; > > struct kvec err_iov[3] = {}; > > int err_buftype[3] = {}; > > + bool islink; > > + int rc, rc2; > > > > *adjust_tz = false; > > *reparse = false; > > @@ -580,15 +581,15 @@ int smb2_query_path_info(const unsigned int xid, struct cifs_tcon *tcon, > > SMB2_OP_QUERY_INFO, cfile, NULL, NULL, > > NULL, NULL); > > goto out; > > - } else if (rc != -EREMOTE && IS_ENABLED(CONFIG_CIFS_DFS_UPCALL) && > > - hdr->Status == STATUS_OBJECT_NAME_INVALID) { > > - /* > > - * Handle weird Windows SMB server behaviour. It responds with > > - * STATUS_OBJECT_NAME_INVALID code to SMB2 QUERY_INFO request > > - * for "\<server>\<dfsname>\<linkpath>" DFS reference, > > - * where <dfsname> contains non-ASCII unicode symbols. > > - */ > > - rc = -EREMOTE; > > + } else if (rc != -EREMOTE && hdr->Status == STATUS_OBJECT_NAME_INVALID) { > > + rc2 = cifs_inval_name_dfs_link_error(xid, tcon, cifs_sb, > > + full_path, &islink); > > + if (rc2) { > > + rc = rc2; > > + goto out; > > + } > > + if (islink) > > + rc = -EREMOTE; > > } > > if (rc == -EREMOTE && IS_ENABLED(CONFIG_CIFS_DFS_UPCALL) && cifs_sb && > > (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS)) > > diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c > > index f79b075f2992..6dfb865ee9d7 100644 > > --- a/fs/cifs/smb2ops.c > > +++ b/fs/cifs/smb2ops.c > > @@ -796,7 +796,6 @@ static int > > smb2_is_path_accessible(const unsigned int xid, struct cifs_tcon *tcon, > > struct cifs_sb_info *cifs_sb, const char *full_path) > > { > > - int rc; > > __le16 *utf16_path; > > __u8 oplock = SMB2_OPLOCK_LEVEL_NONE; > > int err_buftype = CIFS_NO_BUFFER; > > @@ -804,6 +803,8 @@ smb2_is_path_accessible(const unsigned int xid, struct cifs_tcon *tcon, > > struct kvec err_iov = {}; > > struct cifs_fid fid; > > struct cached_fid *cfid; > > + bool islink; > > + int rc, rc2; > > > > rc = open_cached_dir(xid, tcon, full_path, cifs_sb, true, &cfid); > > if (!rc) { > > @@ -833,15 +834,17 @@ smb2_is_path_accessible(const unsigned int xid, struct cifs_tcon *tcon, > > > > if (unlikely(!hdr || err_buftype == CIFS_NO_BUFFER)) > > goto out; > > - /* > > - * Handle weird Windows SMB server behaviour. It responds with > > - * STATUS_OBJECT_NAME_INVALID code to SMB2 QUERY_INFO request > > - * for "\<server>\<dfsname>\<linkpath>" DFS reference, > > - * where <dfsname> contains non-ASCII unicode symbols. > > - */ > > - if (rc != -EREMOTE && IS_ENABLED(CONFIG_CIFS_DFS_UPCALL) && > > - hdr->Status == STATUS_OBJECT_NAME_INVALID) > > - rc = -EREMOTE; > > + > > + if (rc != -EREMOTE && hdr->Status == STATUS_OBJECT_NAME_INVALID) { > > + rc2 = cifs_inval_name_dfs_link_error(xid, tcon, cifs_sb, > > + full_path, &islink); > > + if (rc2) { > > + rc = rc2; > > + goto out; > > + } > > + if (islink) > > + rc = -EREMOTE; > > + } > > if (rc == -EREMOTE && IS_ENABLED(CONFIG_CIFS_DFS_UPCALL) && cifs_sb && > > (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS)) > > rc = -EOPNOTSUPP; > > -- > > 2.39.2 > >
diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h index b7a36ebd0f2f..20a2f0f3f682 100644 --- a/fs/cifs/cifsproto.h +++ b/fs/cifs/cifsproto.h @@ -667,11 +667,21 @@ static inline int get_dfs_path(const unsigned int xid, struct cifs_ses *ses, int match_target_ip(struct TCP_Server_Info *server, const char *share, size_t share_len, bool *result); - -int cifs_dfs_query_info_nonascii_quirk(const unsigned int xid, - struct cifs_tcon *tcon, - struct cifs_sb_info *cifs_sb, - const char *dfs_link_path); +int cifs_inval_name_dfs_link_error(const unsigned int xid, + struct cifs_tcon *tcon, + struct cifs_sb_info *cifs_sb, + const char *full_path, + bool *islink); +#else +static inline int cifs_inval_name_dfs_link_error(const unsigned int xid, + struct cifs_tcon *tcon, + struct cifs_sb_info *cifs_sb, + const char *full_path, + bool *islink) +{ + *islink = false; + return 0; +} #endif static inline int cifs_create_options(struct cifs_sb_info *cifs_sb, int options) diff --git a/fs/cifs/misc.c b/fs/cifs/misc.c index 2905734eb289..0c6c1fc8dae9 100644 --- a/fs/cifs/misc.c +++ b/fs/cifs/misc.c @@ -21,6 +21,7 @@ #include "cifsfs.h" #ifdef CONFIG_CIFS_DFS_UPCALL #include "dns_resolve.h" +#include "dfs_cache.h" #endif #include "fs_context.h" #include "cached_dir.h" @@ -1198,4 +1199,70 @@ int cifs_update_super_prepath(struct cifs_sb_info *cifs_sb, char *prefix) cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH; return 0; } + +/* + * Handle weird Windows SMB server behaviour. It responds with + * STATUS_OBJECT_NAME_INVALID code to SMB2 QUERY_INFO request for + * "\<server>\<dfsname>\<linkpath>" DFS reference, where <dfsname> contains + * non-ASCII unicode symbols. + */ +int cifs_inval_name_dfs_link_error(const unsigned int xid, + struct cifs_tcon *tcon, + struct cifs_sb_info *cifs_sb, + const char *full_path, + bool *islink) +{ + struct cifs_ses *ses = tcon->ses; + size_t len; + char *path; + char *ref_path; + + *islink = false; + + /* + * Fast path - skip check when @full_path doesn't have a prefix path to + * look up or tcon is not DFS. + */ + if (strlen(full_path) < 2 || !cifs_sb || + (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS) || + !is_tcon_dfs(tcon) || !ses->server->origin_fullpath) + return 0; + + /* + * Slow path - tcon is DFS and @full_path has prefix path, so attempt + * to get a referral to figure out whether it is an DFS link. + */ + len = strnlen(tcon->tree_name, MAX_TREE_SIZE + 1) + strlen(full_path) + 1; + path = kmalloc(len, GFP_KERNEL); + if (!path) + return -ENOMEM; + + scnprintf(path, len, "%s%s", tcon->tree_name, full_path); + ref_path = dfs_cache_canonical_path(path + 1, cifs_sb->local_nls, + cifs_remap(cifs_sb)); + kfree(path); + + if (IS_ERR(ref_path)) { + if (PTR_ERR(ref_path) != -EINVAL) + return PTR_ERR(ref_path); + } else { + struct dfs_info3_param *refs = NULL; + int num_refs = 0; + + /* + * XXX: we are not using dfs_cache_find() here because we might + * end filling all the DFS cache and thus potentially + * removing cached DFS targets that the client would eventually + * need during failover. + */ + if (ses->server->ops->get_dfs_refer && + !ses->server->ops->get_dfs_refer(xid, ses, ref_path, &refs, + &num_refs, cifs_sb->local_nls, + cifs_remap(cifs_sb))) + *islink = refs[0].server_type == DFS_TYPE_LINK; + free_dfs_info_array(refs, num_refs); + kfree(ref_path); + } + return 0; +} #endif diff --git a/fs/cifs/smb2inode.c b/fs/cifs/smb2inode.c index 37b4cd59245d..9b956294e864 100644 --- a/fs/cifs/smb2inode.c +++ b/fs/cifs/smb2inode.c @@ -527,12 +527,13 @@ int smb2_query_path_info(const unsigned int xid, struct cifs_tcon *tcon, struct cifs_sb_info *cifs_sb, const char *full_path, struct cifs_open_info_data *data, bool *adjust_tz, bool *reparse) { - int rc; __u32 create_options = 0; struct cifsFileInfo *cfile; struct cached_fid *cfid = NULL; struct kvec err_iov[3] = {}; int err_buftype[3] = {}; + bool islink; + int rc, rc2; *adjust_tz = false; *reparse = false; @@ -580,15 +581,15 @@ int smb2_query_path_info(const unsigned int xid, struct cifs_tcon *tcon, SMB2_OP_QUERY_INFO, cfile, NULL, NULL, NULL, NULL); goto out; - } else if (rc != -EREMOTE && IS_ENABLED(CONFIG_CIFS_DFS_UPCALL) && - hdr->Status == STATUS_OBJECT_NAME_INVALID) { - /* - * Handle weird Windows SMB server behaviour. It responds with - * STATUS_OBJECT_NAME_INVALID code to SMB2 QUERY_INFO request - * for "\<server>\<dfsname>\<linkpath>" DFS reference, - * where <dfsname> contains non-ASCII unicode symbols. - */ - rc = -EREMOTE; + } else if (rc != -EREMOTE && hdr->Status == STATUS_OBJECT_NAME_INVALID) { + rc2 = cifs_inval_name_dfs_link_error(xid, tcon, cifs_sb, + full_path, &islink); + if (rc2) { + rc = rc2; + goto out; + } + if (islink) + rc = -EREMOTE; } if (rc == -EREMOTE && IS_ENABLED(CONFIG_CIFS_DFS_UPCALL) && cifs_sb && (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS)) diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c index f79b075f2992..6dfb865ee9d7 100644 --- a/fs/cifs/smb2ops.c +++ b/fs/cifs/smb2ops.c @@ -796,7 +796,6 @@ static int smb2_is_path_accessible(const unsigned int xid, struct cifs_tcon *tcon, struct cifs_sb_info *cifs_sb, const char *full_path) { - int rc; __le16 *utf16_path; __u8 oplock = SMB2_OPLOCK_LEVEL_NONE; int err_buftype = CIFS_NO_BUFFER; @@ -804,6 +803,8 @@ smb2_is_path_accessible(const unsigned int xid, struct cifs_tcon *tcon, struct kvec err_iov = {}; struct cifs_fid fid; struct cached_fid *cfid; + bool islink; + int rc, rc2; rc = open_cached_dir(xid, tcon, full_path, cifs_sb, true, &cfid); if (!rc) { @@ -833,15 +834,17 @@ smb2_is_path_accessible(const unsigned int xid, struct cifs_tcon *tcon, if (unlikely(!hdr || err_buftype == CIFS_NO_BUFFER)) goto out; - /* - * Handle weird Windows SMB server behaviour. It responds with - * STATUS_OBJECT_NAME_INVALID code to SMB2 QUERY_INFO request - * for "\<server>\<dfsname>\<linkpath>" DFS reference, - * where <dfsname> contains non-ASCII unicode symbols. - */ - if (rc != -EREMOTE && IS_ENABLED(CONFIG_CIFS_DFS_UPCALL) && - hdr->Status == STATUS_OBJECT_NAME_INVALID) - rc = -EREMOTE; + + if (rc != -EREMOTE && hdr->Status == STATUS_OBJECT_NAME_INVALID) { + rc2 = cifs_inval_name_dfs_link_error(xid, tcon, cifs_sb, + full_path, &islink); + if (rc2) { + rc = rc2; + goto out; + } + if (islink) + rc = -EREMOTE; + } if (rc == -EREMOTE && IS_ENABLED(CONFIG_CIFS_DFS_UPCALL) && cifs_sb && (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS)) rc = -EOPNOTSUPP;
Do not map STATUS_OBJECT_NAME_INVALID to -EREMOTE under non-DFS shares, or 'nodfs' mounts or CONFIG_CIFS_DFS_UPCALL=n builds. Otherwise, in the slow path, get a referral to figure out whether it is an actual DFS link. This could be simply reproduced under a non-DFS share by running the following $ mount.cifs //srv/share /mnt -o ... $ cat /mnt/$(printf '\U110000') cat: '/mnt/'$'\364\220\200\200': Object is remote Fixes: c877ce47e137 ("cifs: reduce roundtrips on create/qinfo requests") Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com> --- v1 -> v2: fixed mem leak on PTR_ERR(ref_path) != -EINVAL fs/cifs/cifsproto.h | 20 ++++++++++---- fs/cifs/misc.c | 67 +++++++++++++++++++++++++++++++++++++++++++++ fs/cifs/smb2inode.c | 21 +++++++------- fs/cifs/smb2ops.c | 23 +++++++++------- 4 files changed, 106 insertions(+), 25 deletions(-)