diff options
| -rw-r--r-- | fs/fuse/dir.c | 64 | ||||
| -rw-r--r-- | fs/fuse/fuse_i.h | 3 | ||||
| -rw-r--r-- | fs/fuse/inode.c | 4 | ||||
| -rw-r--r-- | include/uapi/linux/fuse.h | 17 |
4 files changed, 84 insertions, 4 deletions
diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c index fa6381f199b3..0c1d7e387f0d 100644 --- a/fs/fuse/dir.c +++ b/fs/fuse/dir.c @@ -521,7 +521,63 @@ out_err: return err; } -static int get_create_ext(struct fuse_args *args, struct dentry *dentry, +static void *extend_arg(struct fuse_in_arg *buf, u32 bytes) +{ + void *p; + u32 newlen = buf->size + bytes; + + p = krealloc(buf->value, newlen, GFP_KERNEL); + if (!p) { + kfree(buf->value); + buf->size = 0; + buf->value = NULL; + return NULL; + } + + memset(p + buf->size, 0, bytes); + buf->value = p; + buf->size = newlen; + + return p + newlen - bytes; +} + +static u32 fuse_ext_size(size_t size) +{ + return FUSE_REC_ALIGN(sizeof(struct fuse_ext_header) + size); +} + +/* + * This adds just a single supplementary group that matches the parent's group. + */ +static int get_create_supp_group(struct inode *dir, struct fuse_in_arg *ext) +{ + struct fuse_conn *fc = get_fuse_conn(dir); + struct fuse_ext_header *xh; + struct fuse_supp_groups *sg; + kgid_t kgid = dir->i_gid; + gid_t parent_gid = from_kgid(fc->user_ns, kgid); + u32 sg_len = fuse_ext_size(sizeof(*sg) + sizeof(sg->groups[0])); + + if (parent_gid == (gid_t) -1 || gid_eq(kgid, current_fsgid()) || + !in_group_p(kgid)) + return 0; + + xh = extend_arg(ext, sg_len); + if (!xh) + return -ENOMEM; + + xh->size = sg_len; + xh->type = FUSE_EXT_GROUPS; + + sg = (struct fuse_supp_groups *) &xh[1]; + sg->nr_groups = 1; + sg->groups[0] = parent_gid; + + return 0; +} + +static int get_create_ext(struct fuse_args *args, + struct inode *dir, struct dentry *dentry, umode_t mode) { struct fuse_conn *fc = get_fuse_conn_super(dentry->d_sb); @@ -530,6 +586,8 @@ static int get_create_ext(struct fuse_args *args, struct dentry *dentry, if (fc->init_security) err = get_security_context(dentry, mode, &ext); + if (!err && fc->create_supp_group) + err = get_create_supp_group(dir, &ext); if (!err && ext.size) { WARN_ON(args->in_numargs >= ARRAY_SIZE(args->in_args)); @@ -612,7 +670,7 @@ static int fuse_create_open(struct inode *dir, struct dentry *entry, args.out_args[1].size = sizeof(outopen); args.out_args[1].value = &outopen; - err = get_create_ext(&args, entry, mode); + err = get_create_ext(&args, dir, entry, mode); if (err) goto out_put_forget_req; @@ -739,7 +797,7 @@ static int create_new_entry(struct fuse_mount *fm, struct fuse_args *args, args->out_args[0].value = &outarg; if (args->opcode != FUSE_LINK) { - err = get_create_ext(args, entry, mode); + err = get_create_ext(args, dir, entry, mode); if (err) goto out_put_forget_req; } diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h index ac300f14aa2d..e13a8eff2e3d 100644 --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -783,6 +783,9 @@ struct fuse_conn { /* Initialize security xattrs when creating a new inode */ unsigned int init_security:1; + /* Add supplementary group info when creating a new inode */ + unsigned int create_supp_group:1; + /* Does the filesystem support per inode DAX? */ unsigned int inode_dax:1; diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index 6b3beda16c1b..114bdb3f7ccb 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -1201,6 +1201,8 @@ static void process_init_reply(struct fuse_mount *fm, struct fuse_args *args, fc->setxattr_ext = 1; if (flags & FUSE_SECURITY_CTX) fc->init_security = 1; + if (flags & FUSE_CREATE_SUPP_GROUP) + fc->create_supp_group = 1; } else { ra_pages = fc->max_read / PAGE_SIZE; fc->no_lock = 1; @@ -1246,7 +1248,7 @@ void fuse_send_init(struct fuse_mount *fm) FUSE_ABORT_ERROR | FUSE_MAX_PAGES | FUSE_CACHE_SYMLINKS | FUSE_NO_OPENDIR_SUPPORT | FUSE_EXPLICIT_INVAL_DATA | FUSE_HANDLE_KILLPRIV_V2 | FUSE_SETXATTR_EXT | FUSE_INIT_EXT | - FUSE_SECURITY_CTX; + FUSE_SECURITY_CTX | FUSE_CREATE_SUPP_GROUP; #ifdef CONFIG_FUSE_DAX if (fm->fc->dax) flags |= FUSE_MAP_ALIGNMENT; diff --git a/include/uapi/linux/fuse.h b/include/uapi/linux/fuse.h index c71f12429e3d..1b9d0dfae72d 100644 --- a/include/uapi/linux/fuse.h +++ b/include/uapi/linux/fuse.h @@ -204,6 +204,8 @@ * - add total_extlen to fuse_in_header * - add FUSE_MAX_NR_SECCTX * - add extension header + * - add FUSE_EXT_GROUPS + * - add FUSE_CREATE_SUPP_GROUP */ #ifndef _LINUX_FUSE_H @@ -365,6 +367,8 @@ struct fuse_file_lock { * FUSE_SECURITY_CTX: add security context to create, mkdir, symlink, and * mknod * FUSE_HAS_INODE_DAX: use per inode DAX + * FUSE_CREATE_SUPP_GROUP: add supplementary group info to create, mkdir, + * symlink and mknod (single group that matches parent) */ #define FUSE_ASYNC_READ (1 << 0) #define FUSE_POSIX_LOCKS (1 << 1) @@ -401,6 +405,7 @@ struct fuse_file_lock { /* bits 32..63 get shifted down 32 bits into the flags2 field */ #define FUSE_SECURITY_CTX (1ULL << 32) #define FUSE_HAS_INODE_DAX (1ULL << 33) +#define FUSE_CREATE_SUPP_GROUP (1ULL << 34) /** * CUSE INIT request/reply flags @@ -509,10 +514,12 @@ struct fuse_file_lock { /** * extension type * FUSE_MAX_NR_SECCTX: maximum value of &fuse_secctx_header.nr_secctx + * FUSE_EXT_GROUPS: &fuse_supp_groups extension */ enum fuse_ext_type { /* Types 0..31 are reserved for fuse_secctx_header */ FUSE_MAX_NR_SECCTX = 31, + FUSE_EXT_GROUPS = 32, }; enum fuse_opcode { @@ -1073,4 +1080,14 @@ struct fuse_ext_header { uint32_t type; }; +/** + * struct fuse_supp_groups - Supplementary group extension + * @nr_groups: number of supplementary groups + * @groups: flexible array of group IDs + */ +struct fuse_supp_groups { + uint32_t nr_groups; + uint32_t groups[]; +}; + #endif /* _LINUX_FUSE_H */ |