From 49024ec8795ed2bd7217c249ef50a70c4e25d662 Mon Sep 17 00:00:00 2001 From: Paulo Alcantara Date: Tue, 27 Jun 2023 21:24:47 -0300 Subject: [PATCH] smb: client: fix parsing of source mount option 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) Cc: stable@vger.kernel.org Signed-off-by: Steve French --- fs/smb/client/cifs_dfs_ref.c | 20 ++++++++++----- 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, 80 insertions(+), 56 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); + rc = smb3_parse_devname(full_path, ctx); if (rc) { mnt = ERR_PTR(rc); goto out; } - rc = smb3_parse_devname(full_path, ctx); + 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 @@ out: 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 1bda75609b64..4946a0c59600 100644 --- a/fs/smb/client/fs_context.c +++ b/fs/smb/client/fs_context.c @@ -441,14 +441,17 @@ out: * 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)) @@ -469,8 +472,39 @@ 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; } /* @@ -484,6 +518,7 @@ 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"); @@ -511,6 +546,8 @@ 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; @@ -533,8 +570,11 @@ 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; } @@ -1146,12 +1186,13 @@ 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; -- 2.11.0