| Message ID | 20230628002450.18781-1-pc@manguebit.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/4] smb: client: fix parsing of source mount option | expand |
tentatively merged patches On Tue, Jun 27, 2023 at 7:25 PM Paulo Alcantara <pc@manguebit.com> wrote: > > Handle trailing and leading separators when parsing UNC and prefix > paths in smb3_parse_devname(). Then, store the sanitised paths in > smb3_fs_context::source. > > This fixes the following cases > > $ mount //srv/share// /mnt/1 -o ... > $ cat /mnt/1/d0/f0 > cat: /mnt/1/d0/f0: Invalid argument > > The -EINVAL was returned because the client sent SMB2_CREATE "\\d0\f0" > rather than SMB2_CREATE "\d0\f0". > > $ mount //srv//share /mnt/1 -o ... > mount: Invalid argument > > The -EINVAL was returned correctly although the client only realised > it after sending a couple of bad requests rather than bailing out > earlier when parsing mount options. > > Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com> > --- > fs/smb/client/cifs_dfs_ref.c | 28 +++++++++++------ > fs/smb/client/cifsproto.h | 2 ++ > fs/smb/client/dfs.c | 38 ++--------------------- > fs/smb/client/fs_context.c | 59 ++++++++++++++++++++++++++++++------ > fs/smb/client/misc.c | 17 +++++++---- > 5 files changed, 84 insertions(+), 60 deletions(-) > > diff --git a/fs/smb/client/cifs_dfs_ref.c b/fs/smb/client/cifs_dfs_ref.c > index 0329a907bdfe..b1c2499b1c3b 100644 > --- a/fs/smb/client/cifs_dfs_ref.c > +++ b/fs/smb/client/cifs_dfs_ref.c > @@ -118,12 +118,12 @@ cifs_build_devname(char *nodename, const char *prepath) > return dev; > } > > -static int set_dest_addr(struct smb3_fs_context *ctx, const char *full_path) > +static int set_dest_addr(struct smb3_fs_context *ctx) > { > struct sockaddr *addr = (struct sockaddr *)&ctx->dstaddr; > int rc; > > - rc = dns_resolve_server_name_to_ip(full_path, addr, NULL); > + rc = dns_resolve_server_name_to_ip(ctx->source, addr, NULL); > if (!rc) > cifs_set_port(addr, ctx->port); > return rc; > @@ -171,10 +171,9 @@ static struct vfsmount *cifs_dfs_do_automount(struct path *path) > mnt = ERR_CAST(full_path); > goto out; > } > - cifs_dbg(FYI, "%s: full_path: %s\n", __func__, full_path); > > tmp = *cur_ctx; > - tmp.source = full_path; > + tmp.source = NULL; > tmp.leaf_fullpath = NULL; > tmp.UNC = tmp.prepath = NULL; > tmp.dfs_root_ses = NULL; > @@ -185,13 +184,22 @@ static struct vfsmount *cifs_dfs_do_automount(struct path *path) > goto out; > } > > - rc = set_dest_addr(ctx, full_path); > - if (rc) { > - mnt = ERR_PTR(rc); > - goto out; > - } > - > rc = smb3_parse_devname(full_path, ctx); > + if (rc) { > + mnt = ERR_PTR(rc); > + goto out; > + } > + > + ctx->source = smb3_fs_context_fullpath(ctx, '/'); > + if (IS_ERR(ctx->source)) { > + mnt = ERR_CAST(ctx->source); > + ctx->source = NULL; > + goto out; > + } > + cifs_dbg(FYI, "%s: ctx: source=%s UNC=%s prepath=%s dstaddr=%pISpc\n", > + __func__, ctx->source, ctx->UNC, ctx->prepath, &ctx->dstaddr); > + > + rc = set_dest_addr(ctx); > if (!rc) > mnt = fc_mount(fc); > else > diff --git a/fs/smb/client/cifsproto.h b/fs/smb/client/cifsproto.h > index d127aded2f28..293c54867d94 100644 > --- a/fs/smb/client/cifsproto.h > +++ b/fs/smb/client/cifsproto.h > @@ -85,6 +85,8 @@ extern void release_mid(struct mid_q_entry *mid); > extern void cifs_wake_up_task(struct mid_q_entry *mid); > extern int cifs_handle_standard(struct TCP_Server_Info *server, > struct mid_q_entry *mid); > +extern char *smb3_fs_context_fullpath(const struct smb3_fs_context *ctx, > + char dirsep); > extern int smb3_parse_devname(const char *devname, struct smb3_fs_context *ctx); > extern int smb3_parse_opt(const char *options, const char *key, char **val); > extern int cifs_ipaddr_cmp(struct sockaddr *srcaddr, struct sockaddr *rhs); > diff --git a/fs/smb/client/dfs.c b/fs/smb/client/dfs.c > index 2390b2fedd6a..d741f396c527 100644 > --- a/fs/smb/client/dfs.c > +++ b/fs/smb/client/dfs.c > @@ -54,39 +54,6 @@ int dfs_parse_target_referral(const char *full_path, const struct dfs_info3_para > return rc; > } > > -/* > - * cifs_build_path_to_root returns full path to root when we do not have an > - * existing connection (tcon) > - */ > -static char *build_unc_path_to_root(const struct smb3_fs_context *ctx, > - const struct cifs_sb_info *cifs_sb, bool useppath) > -{ > - char *full_path, *pos; > - unsigned int pplen = useppath && ctx->prepath ? strlen(ctx->prepath) + 1 : 0; > - unsigned int unc_len = strnlen(ctx->UNC, MAX_TREE_SIZE + 1); > - > - if (unc_len > MAX_TREE_SIZE) > - return ERR_PTR(-EINVAL); > - > - full_path = kmalloc(unc_len + pplen + 1, GFP_KERNEL); > - if (full_path == NULL) > - return ERR_PTR(-ENOMEM); > - > - memcpy(full_path, ctx->UNC, unc_len); > - pos = full_path + unc_len; > - > - if (pplen) { > - *pos = CIFS_DIR_SEP(cifs_sb); > - memcpy(pos + 1, ctx->prepath, pplen); > - pos += pplen; > - } > - > - *pos = '\0'; /* add trailing null */ > - convert_delimiter(full_path, CIFS_DIR_SEP(cifs_sb)); > - cifs_dbg(FYI, "%s: full_path=%s\n", __func__, full_path); > - return full_path; > -} > - > static int get_session(struct cifs_mount_ctx *mnt_ctx, const char *full_path) > { > struct smb3_fs_context *ctx = mnt_ctx->fs_ctx; > @@ -179,6 +146,7 @@ static int __dfs_mount_share(struct cifs_mount_ctx *mnt_ctx) > struct TCP_Server_Info *server; > struct cifs_tcon *tcon; > char *origin_fullpath = NULL; > + char sep = CIFS_DIR_SEP(cifs_sb); > int num_links = 0; > int rc; > > @@ -186,7 +154,7 @@ static int __dfs_mount_share(struct cifs_mount_ctx *mnt_ctx) > if (IS_ERR(ref_path)) > return PTR_ERR(ref_path); > > - full_path = build_unc_path_to_root(ctx, cifs_sb, true); > + full_path = smb3_fs_context_fullpath(ctx, sep); > if (IS_ERR(full_path)) { > rc = PTR_ERR(full_path); > full_path = NULL; > @@ -228,7 +196,7 @@ static int __dfs_mount_share(struct cifs_mount_ctx *mnt_ctx) > kfree(full_path); > ref_path = full_path = NULL; > > - full_path = build_unc_path_to_root(ctx, cifs_sb, true); > + full_path = smb3_fs_context_fullpath(ctx, sep); > if (IS_ERR(full_path)) { > rc = PTR_ERR(full_path); > full_path = NULL; > diff --git a/fs/smb/client/fs_context.c b/fs/smb/client/fs_context.c > index 226d71e12db0..a4b80babd03e 100644 > --- a/fs/smb/client/fs_context.c > +++ b/fs/smb/client/fs_context.c > @@ -442,14 +442,17 @@ int smb3_parse_opt(const char *options, const char *key, char **val) > * but there are some bugs that prevent rename from working if there are > * multiple delimiters. > * > - * Returns a sanitized duplicate of @path. @gfp indicates the GFP_* flags > - * for kstrdup. > + * Return a sanitized duplicate of @path or NULL for empty prefix paths. > + * Otherwise, return ERR_PTR. > + * > + * @gfp indicates the GFP_* flags for kstrdup. > * The caller is responsible for freeing the original. > */ > #define IS_DELIM(c) ((c) == '/' || (c) == '\\') > char *cifs_sanitize_prepath(char *prepath, gfp_t gfp) > { > char *cursor1 = prepath, *cursor2 = prepath; > + char *s; > > /* skip all prepended delimiters */ > while (IS_DELIM(*cursor1)) > @@ -470,8 +473,39 @@ char *cifs_sanitize_prepath(char *prepath, gfp_t gfp) > if (IS_DELIM(*(cursor2 - 1))) > cursor2--; > > - *(cursor2) = '\0'; > - return kstrdup(prepath, gfp); > + *cursor2 = '\0'; > + if (!*prepath) > + return NULL; > + s = kstrdup(prepath, gfp); > + if (!s) > + return ERR_PTR(-ENOMEM); > + return s; > +} > + > +/* > + * Return full path based on the values of @ctx->{UNC,prepath}. > + * > + * It is assumed that both values were already parsed by smb3_parse_devname(). > + */ > +char *smb3_fs_context_fullpath(const struct smb3_fs_context *ctx, char dirsep) > +{ > + size_t ulen, plen; > + char *s; > + > + ulen = strlen(ctx->UNC); > + plen = ctx->prepath ? strlen(ctx->prepath) + 1 : 0; > + > + s = kmalloc(ulen + plen + 1, GFP_KERNEL); > + if (!s) > + return ERR_PTR(-ENOMEM); > + memcpy(s, ctx->UNC, ulen); > + if (plen) { > + s[ulen] = dirsep; > + memcpy(s + ulen + 1, ctx->prepath, plen); > + } > + s[ulen + plen] = '\0'; > + convert_delimiter(s, dirsep); > + return s; > } > > /* > @@ -485,6 +519,7 @@ smb3_parse_devname(const char *devname, struct smb3_fs_context *ctx) > char *pos; > const char *delims = "/\\"; > size_t len; > + int rc; > > if (unlikely(!devname || !*devname)) { > cifs_dbg(VFS, "Device name not specified\n"); > @@ -512,6 +547,8 @@ smb3_parse_devname(const char *devname, struct smb3_fs_context *ctx) > > /* now go until next delimiter or end of string */ > len = strcspn(pos, delims); > + if (!len) > + return -EINVAL; > > /* move "pos" up to delimiter or NULL */ > pos += len; > @@ -534,8 +571,11 @@ smb3_parse_devname(const char *devname, struct smb3_fs_context *ctx) > return 0; > > ctx->prepath = cifs_sanitize_prepath(pos, GFP_KERNEL); > - if (!ctx->prepath) > - return -ENOMEM; > + if (IS_ERR(ctx->prepath)) { > + rc = PTR_ERR(ctx->prepath); > + ctx->prepath = NULL; > + return rc; > + } > > return 0; > } > @@ -1150,12 +1190,13 @@ static int smb3_fs_context_parse_param(struct fs_context *fc, > cifs_errorf(fc, "Unknown error parsing devname\n"); > goto cifs_parse_mount_err; > } > - ctx->source = kstrdup(param->string, GFP_KERNEL); > - if (ctx->source == NULL) { > + ctx->source = smb3_fs_context_fullpath(ctx, '/'); > + if (IS_ERR(ctx->source)) { > + ctx->source = NULL; > cifs_errorf(fc, "OOM when copying UNC string\n"); > goto cifs_parse_mount_err; > } > - fc->source = kstrdup(param->string, GFP_KERNEL); > + fc->source = kstrdup(ctx->source, GFP_KERNEL); > if (fc->source == NULL) { > cifs_errorf(fc, "OOM when copying UNC string\n"); > goto cifs_parse_mount_err; > diff --git a/fs/smb/client/misc.c b/fs/smb/client/misc.c > index cd914be905b2..609d0c0d9eca 100644 > --- a/fs/smb/client/misc.c > +++ b/fs/smb/client/misc.c > @@ -1198,16 +1198,21 @@ int match_target_ip(struct TCP_Server_Info *server, > > int cifs_update_super_prepath(struct cifs_sb_info *cifs_sb, char *prefix) > { > + int rc; > + > kfree(cifs_sb->prepath); > + cifs_sb->prepath = NULL; > > if (prefix && *prefix) { > cifs_sb->prepath = cifs_sanitize_prepath(prefix, GFP_ATOMIC); > - if (!cifs_sb->prepath) > - return -ENOMEM; > - > - convert_delimiter(cifs_sb->prepath, CIFS_DIR_SEP(cifs_sb)); > - } else > - cifs_sb->prepath = NULL; > + if (IS_ERR(cifs_sb->prepath)) { > + rc = PTR_ERR(cifs_sb->prepath); > + cifs_sb->prepath = NULL; > + return rc; > + } > + if (cifs_sb->prepath) > + convert_delimiter(cifs_sb->prepath, CIFS_DIR_SEP(cifs_sb)); > + } > > cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH; > return 0; > -- > 2.41.0 >
diff --git a/fs/smb/client/cifs_dfs_ref.c b/fs/smb/client/cifs_dfs_ref.c index 0329a907bdfe..b1c2499b1c3b 100644 --- a/fs/smb/client/cifs_dfs_ref.c +++ b/fs/smb/client/cifs_dfs_ref.c @@ -118,12 +118,12 @@ cifs_build_devname(char *nodename, const char *prepath) return dev; } -static int set_dest_addr(struct smb3_fs_context *ctx, const char *full_path) +static int set_dest_addr(struct smb3_fs_context *ctx) { struct sockaddr *addr = (struct sockaddr *)&ctx->dstaddr; int rc; - rc = dns_resolve_server_name_to_ip(full_path, addr, NULL); + rc = dns_resolve_server_name_to_ip(ctx->source, addr, NULL); if (!rc) cifs_set_port(addr, ctx->port); return rc; @@ -171,10 +171,9 @@ static struct vfsmount *cifs_dfs_do_automount(struct path *path) mnt = ERR_CAST(full_path); goto out; } - cifs_dbg(FYI, "%s: full_path: %s\n", __func__, full_path); tmp = *cur_ctx; - tmp.source = full_path; + tmp.source = NULL; tmp.leaf_fullpath = NULL; tmp.UNC = tmp.prepath = NULL; tmp.dfs_root_ses = NULL; @@ -185,13 +184,22 @@ static struct vfsmount *cifs_dfs_do_automount(struct path *path) goto out; } - rc = set_dest_addr(ctx, full_path); - if (rc) { - mnt = ERR_PTR(rc); - goto out; - } - rc = smb3_parse_devname(full_path, ctx); + if (rc) { + mnt = ERR_PTR(rc); + goto out; + } + + ctx->source = smb3_fs_context_fullpath(ctx, '/'); + if (IS_ERR(ctx->source)) { + mnt = ERR_CAST(ctx->source); + ctx->source = NULL; + goto out; + } + cifs_dbg(FYI, "%s: ctx: source=%s UNC=%s prepath=%s dstaddr=%pISpc\n", + __func__, ctx->source, ctx->UNC, ctx->prepath, &ctx->dstaddr); + + rc = set_dest_addr(ctx); if (!rc) mnt = fc_mount(fc); else diff --git a/fs/smb/client/cifsproto.h b/fs/smb/client/cifsproto.h index d127aded2f28..293c54867d94 100644 --- a/fs/smb/client/cifsproto.h +++ b/fs/smb/client/cifsproto.h @@ -85,6 +85,8 @@ extern void release_mid(struct mid_q_entry *mid); extern void cifs_wake_up_task(struct mid_q_entry *mid); extern int cifs_handle_standard(struct TCP_Server_Info *server, struct mid_q_entry *mid); +extern char *smb3_fs_context_fullpath(const struct smb3_fs_context *ctx, + char dirsep); extern int smb3_parse_devname(const char *devname, struct smb3_fs_context *ctx); extern int smb3_parse_opt(const char *options, const char *key, char **val); extern int cifs_ipaddr_cmp(struct sockaddr *srcaddr, struct sockaddr *rhs); diff --git a/fs/smb/client/dfs.c b/fs/smb/client/dfs.c index 2390b2fedd6a..d741f396c527 100644 --- a/fs/smb/client/dfs.c +++ b/fs/smb/client/dfs.c @@ -54,39 +54,6 @@ int dfs_parse_target_referral(const char *full_path, const struct dfs_info3_para return rc; } -/* - * cifs_build_path_to_root returns full path to root when we do not have an - * existing connection (tcon) - */ -static char *build_unc_path_to_root(const struct smb3_fs_context *ctx, - const struct cifs_sb_info *cifs_sb, bool useppath) -{ - char *full_path, *pos; - unsigned int pplen = useppath && ctx->prepath ? strlen(ctx->prepath) + 1 : 0; - unsigned int unc_len = strnlen(ctx->UNC, MAX_TREE_SIZE + 1); - - if (unc_len > MAX_TREE_SIZE) - return ERR_PTR(-EINVAL); - - full_path = kmalloc(unc_len + pplen + 1, GFP_KERNEL); - if (full_path == NULL) - return ERR_PTR(-ENOMEM); - - memcpy(full_path, ctx->UNC, unc_len); - pos = full_path + unc_len; - - if (pplen) { - *pos = CIFS_DIR_SEP(cifs_sb); - memcpy(pos + 1, ctx->prepath, pplen); - pos += pplen; - } - - *pos = '\0'; /* add trailing null */ - convert_delimiter(full_path, CIFS_DIR_SEP(cifs_sb)); - cifs_dbg(FYI, "%s: full_path=%s\n", __func__, full_path); - return full_path; -} - static int get_session(struct cifs_mount_ctx *mnt_ctx, const char *full_path) { struct smb3_fs_context *ctx = mnt_ctx->fs_ctx; @@ -179,6 +146,7 @@ static int __dfs_mount_share(struct cifs_mount_ctx *mnt_ctx) struct TCP_Server_Info *server; struct cifs_tcon *tcon; char *origin_fullpath = NULL; + char sep = CIFS_DIR_SEP(cifs_sb); int num_links = 0; int rc; @@ -186,7 +154,7 @@ static int __dfs_mount_share(struct cifs_mount_ctx *mnt_ctx) if (IS_ERR(ref_path)) return PTR_ERR(ref_path); - full_path = build_unc_path_to_root(ctx, cifs_sb, true); + full_path = smb3_fs_context_fullpath(ctx, sep); if (IS_ERR(full_path)) { rc = PTR_ERR(full_path); full_path = NULL; @@ -228,7 +196,7 @@ static int __dfs_mount_share(struct cifs_mount_ctx *mnt_ctx) kfree(full_path); ref_path = full_path = NULL; - full_path = build_unc_path_to_root(ctx, cifs_sb, true); + full_path = smb3_fs_context_fullpath(ctx, sep); if (IS_ERR(full_path)) { rc = PTR_ERR(full_path); full_path = NULL; diff --git a/fs/smb/client/fs_context.c b/fs/smb/client/fs_context.c index 226d71e12db0..a4b80babd03e 100644 --- a/fs/smb/client/fs_context.c +++ b/fs/smb/client/fs_context.c @@ -442,14 +442,17 @@ int smb3_parse_opt(const char *options, const char *key, char **val) * but there are some bugs that prevent rename from working if there are * multiple delimiters. * - * Returns a sanitized duplicate of @path. @gfp indicates the GFP_* flags - * for kstrdup. + * Return a sanitized duplicate of @path or NULL for empty prefix paths. + * Otherwise, return ERR_PTR. + * + * @gfp indicates the GFP_* flags for kstrdup. * The caller is responsible for freeing the original. */ #define IS_DELIM(c) ((c) == '/' || (c) == '\\') char *cifs_sanitize_prepath(char *prepath, gfp_t gfp) { char *cursor1 = prepath, *cursor2 = prepath; + char *s; /* skip all prepended delimiters */ while (IS_DELIM(*cursor1)) @@ -470,8 +473,39 @@ char *cifs_sanitize_prepath(char *prepath, gfp_t gfp) if (IS_DELIM(*(cursor2 - 1))) cursor2--; - *(cursor2) = '\0'; - return kstrdup(prepath, gfp); + *cursor2 = '\0'; + if (!*prepath) + return NULL; + s = kstrdup(prepath, gfp); + if (!s) + return ERR_PTR(-ENOMEM); + return s; +} + +/* + * Return full path based on the values of @ctx->{UNC,prepath}. + * + * It is assumed that both values were already parsed by smb3_parse_devname(). + */ +char *smb3_fs_context_fullpath(const struct smb3_fs_context *ctx, char dirsep) +{ + size_t ulen, plen; + char *s; + + ulen = strlen(ctx->UNC); + plen = ctx->prepath ? strlen(ctx->prepath) + 1 : 0; + + s = kmalloc(ulen + plen + 1, GFP_KERNEL); + if (!s) + return ERR_PTR(-ENOMEM); + memcpy(s, ctx->UNC, ulen); + if (plen) { + s[ulen] = dirsep; + memcpy(s + ulen + 1, ctx->prepath, plen); + } + s[ulen + plen] = '\0'; + convert_delimiter(s, dirsep); + return s; } /* @@ -485,6 +519,7 @@ smb3_parse_devname(const char *devname, struct smb3_fs_context *ctx) char *pos; const char *delims = "/\\"; size_t len; + int rc; if (unlikely(!devname || !*devname)) { cifs_dbg(VFS, "Device name not specified\n"); @@ -512,6 +547,8 @@ smb3_parse_devname(const char *devname, struct smb3_fs_context *ctx) /* now go until next delimiter or end of string */ len = strcspn(pos, delims); + if (!len) + return -EINVAL; /* move "pos" up to delimiter or NULL */ pos += len; @@ -534,8 +571,11 @@ smb3_parse_devname(const char *devname, struct smb3_fs_context *ctx) return 0; ctx->prepath = cifs_sanitize_prepath(pos, GFP_KERNEL); - if (!ctx->prepath) - return -ENOMEM; + if (IS_ERR(ctx->prepath)) { + rc = PTR_ERR(ctx->prepath); + ctx->prepath = NULL; + return rc; + } return 0; } @@ -1150,12 +1190,13 @@ static int smb3_fs_context_parse_param(struct fs_context *fc, cifs_errorf(fc, "Unknown error parsing devname\n"); goto cifs_parse_mount_err; } - ctx->source = kstrdup(param->string, GFP_KERNEL); - if (ctx->source == NULL) { + ctx->source = smb3_fs_context_fullpath(ctx, '/'); + if (IS_ERR(ctx->source)) { + ctx->source = NULL; cifs_errorf(fc, "OOM when copying UNC string\n"); goto cifs_parse_mount_err; } - fc->source = kstrdup(param->string, GFP_KERNEL); + fc->source = kstrdup(ctx->source, GFP_KERNEL); if (fc->source == NULL) { cifs_errorf(fc, "OOM when copying UNC string\n"); goto cifs_parse_mount_err; diff --git a/fs/smb/client/misc.c b/fs/smb/client/misc.c index cd914be905b2..609d0c0d9eca 100644 --- a/fs/smb/client/misc.c +++ b/fs/smb/client/misc.c @@ -1198,16 +1198,21 @@ int match_target_ip(struct TCP_Server_Info *server, int cifs_update_super_prepath(struct cifs_sb_info *cifs_sb, char *prefix) { + int rc; + kfree(cifs_sb->prepath); + cifs_sb->prepath = NULL; if (prefix && *prefix) { cifs_sb->prepath = cifs_sanitize_prepath(prefix, GFP_ATOMIC); - if (!cifs_sb->prepath) - return -ENOMEM; - - convert_delimiter(cifs_sb->prepath, CIFS_DIR_SEP(cifs_sb)); - } else - cifs_sb->prepath = NULL; + if (IS_ERR(cifs_sb->prepath)) { + rc = PTR_ERR(cifs_sb->prepath); + cifs_sb->prepath = NULL; + return rc; + } + if (cifs_sb->prepath) + convert_delimiter(cifs_sb->prepath, CIFS_DIR_SEP(cifs_sb)); + } cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH; return 0;
Handle trailing and leading separators when parsing UNC and prefix paths in smb3_parse_devname(). Then, store the sanitised paths in smb3_fs_context::source. This fixes the following cases $ mount //srv/share// /mnt/1 -o ... $ cat /mnt/1/d0/f0 cat: /mnt/1/d0/f0: Invalid argument The -EINVAL was returned because the client sent SMB2_CREATE "\\d0\f0" rather than SMB2_CREATE "\d0\f0". $ mount //srv//share /mnt/1 -o ... mount: Invalid argument The -EINVAL was returned correctly although the client only realised it after sending a couple of bad requests rather than bailing out earlier when parsing mount options. Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com> --- fs/smb/client/cifs_dfs_ref.c | 28 +++++++++++------ fs/smb/client/cifsproto.h | 2 ++ fs/smb/client/dfs.c | 38 ++--------------------- fs/smb/client/fs_context.c | 59 ++++++++++++++++++++++++++++++------ fs/smb/client/misc.c | 17 +++++++---- 5 files changed, 84 insertions(+), 60 deletions(-)