diff options
Diffstat (limited to 'fs/xattr.c')
| -rw-r--r-- | fs/xattr.c | 446 |
1 files changed, 292 insertions, 154 deletions
diff --git a/fs/xattr.c b/fs/xattr.c index 05ec7e7d9e87..02bee149ad96 100644 --- a/fs/xattr.c +++ b/fs/xattr.c @@ -586,25 +586,32 @@ retry_deleg: } EXPORT_SYMBOL_GPL(vfs_removexattr); +int import_xattr_name(struct xattr_name *kname, const char __user *name) +{ + int error = strncpy_from_user(kname->name, name, + sizeof(kname->name)); + if (error == 0 || error == sizeof(kname->name)) + return -ERANGE; + if (error < 0) + return error; + return 0; +} + /* * Extended attribute SET operations */ -int setxattr_copy(const char __user *name, struct xattr_ctx *ctx) +int setxattr_copy(const char __user *name, struct kernel_xattr_ctx *ctx) { int error; if (ctx->flags & ~(XATTR_CREATE|XATTR_REPLACE)) return -EINVAL; - error = strncpy_from_user(ctx->kname->name, name, - sizeof(ctx->kname->name)); - if (error == 0 || error == sizeof(ctx->kname->name)) - return -ERANGE; - if (error < 0) + error = import_xattr_name(ctx->kname, name); + if (error) return error; - error = 0; if (ctx->size) { if (ctx->size > XATTR_SIZE_MAX) return -E2BIG; @@ -619,8 +626,8 @@ int setxattr_copy(const char __user *name, struct xattr_ctx *ctx) return error; } -int do_setxattr(struct mnt_idmap *idmap, struct dentry *dentry, - struct xattr_ctx *ctx) +static int do_setxattr(struct mnt_idmap *idmap, struct dentry *dentry, + struct kernel_xattr_ctx *ctx) { if (is_posix_acl_xattr(ctx->kname->name)) return do_set_acl(idmap, dentry, ctx->kname->name, @@ -630,32 +637,32 @@ int do_setxattr(struct mnt_idmap *idmap, struct dentry *dentry, ctx->kvalue, ctx->size, ctx->flags); } -static int path_setxattr(const char __user *pathname, - const char __user *name, const void __user *value, - size_t size, int flags, unsigned int lookup_flags) +int file_setxattr(struct file *f, struct kernel_xattr_ctx *ctx) +{ + int error = mnt_want_write_file(f); + + if (!error) { + audit_file(f); + error = do_setxattr(file_mnt_idmap(f), f->f_path.dentry, ctx); + mnt_drop_write_file(f); + } + return error; +} + +/* unconditionally consumes filename */ +int filename_setxattr(int dfd, struct filename *filename, + unsigned int lookup_flags, struct kernel_xattr_ctx *ctx) { - struct xattr_name kname; - struct xattr_ctx ctx = { - .cvalue = value, - .kvalue = NULL, - .size = size, - .kname = &kname, - .flags = flags, - }; struct path path; int error; - error = setxattr_copy(name, &ctx); - if (error) - return error; - retry: - error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path); + error = filename_lookup(dfd, filename, lookup_flags, &path, NULL); if (error) goto out; error = mnt_want_write(path.mnt); if (!error) { - error = do_setxattr(mnt_idmap(path.mnt), path.dentry, &ctx); + error = do_setxattr(mnt_idmap(path.mnt), path.dentry, ctx); mnt_drop_write(path.mnt); } path_put(&path); @@ -665,80 +672,121 @@ retry: } out: + putname(filename); + return error; +} + +static int path_setxattrat(int dfd, const char __user *pathname, + unsigned int at_flags, const char __user *name, + const void __user *value, size_t size, int flags) +{ + struct xattr_name kname; + struct kernel_xattr_ctx ctx = { + .cvalue = value, + .kvalue = NULL, + .size = size, + .kname = &kname, + .flags = flags, + }; + struct filename *filename; + unsigned int lookup_flags = 0; + int error; + + if ((at_flags & ~(AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH)) != 0) + return -EINVAL; + + if (!(at_flags & AT_SYMLINK_NOFOLLOW)) + lookup_flags = LOOKUP_FOLLOW; + + error = setxattr_copy(name, &ctx); + if (error) + return error; + + filename = getname_maybe_null(pathname, at_flags); + if (!filename) { + CLASS(fd, f)(dfd); + if (fd_empty(f)) + error = -EBADF; + else + error = file_setxattr(fd_file(f), &ctx); + } else { + error = filename_setxattr(dfd, filename, lookup_flags, &ctx); + } kvfree(ctx.kvalue); return error; } +SYSCALL_DEFINE6(setxattrat, int, dfd, const char __user *, pathname, unsigned int, at_flags, + const char __user *, name, const struct xattr_args __user *, uargs, + size_t, usize) +{ + struct xattr_args args = {}; + int error; + + BUILD_BUG_ON(sizeof(struct xattr_args) < XATTR_ARGS_SIZE_VER0); + BUILD_BUG_ON(sizeof(struct xattr_args) != XATTR_ARGS_SIZE_LATEST); + + if (unlikely(usize < XATTR_ARGS_SIZE_VER0)) + return -EINVAL; + if (usize > PAGE_SIZE) + return -E2BIG; + + error = copy_struct_from_user(&args, sizeof(args), uargs, usize); + if (error) + return error; + + return path_setxattrat(dfd, pathname, at_flags, name, + u64_to_user_ptr(args.value), args.size, + args.flags); +} + SYSCALL_DEFINE5(setxattr, const char __user *, pathname, const char __user *, name, const void __user *, value, size_t, size, int, flags) { - return path_setxattr(pathname, name, value, size, flags, LOOKUP_FOLLOW); + return path_setxattrat(AT_FDCWD, pathname, 0, name, value, size, flags); } SYSCALL_DEFINE5(lsetxattr, const char __user *, pathname, const char __user *, name, const void __user *, value, size_t, size, int, flags) { - return path_setxattr(pathname, name, value, size, flags, 0); + return path_setxattrat(AT_FDCWD, pathname, AT_SYMLINK_NOFOLLOW, name, + value, size, flags); } SYSCALL_DEFINE5(fsetxattr, int, fd, const char __user *, name, const void __user *,value, size_t, size, int, flags) { - struct xattr_name kname; - struct xattr_ctx ctx = { - .cvalue = value, - .kvalue = NULL, - .size = size, - .kname = &kname, - .flags = flags, - }; - int error; - - CLASS(fd, f)(fd); - if (!fd_file(f)) - return -EBADF; - - audit_file(fd_file(f)); - error = setxattr_copy(name, &ctx); - if (error) - return error; - - error = mnt_want_write_file(fd_file(f)); - if (!error) { - error = do_setxattr(file_mnt_idmap(fd_file(f)), - fd_file(f)->f_path.dentry, &ctx); - mnt_drop_write_file(fd_file(f)); - } - kvfree(ctx.kvalue); - return error; + return path_setxattrat(fd, NULL, AT_EMPTY_PATH, name, + value, size, flags); } /* * Extended attribute GET operations */ -ssize_t +static ssize_t do_getxattr(struct mnt_idmap *idmap, struct dentry *d, - struct xattr_ctx *ctx) + struct kernel_xattr_ctx *ctx) { ssize_t error; char *kname = ctx->kname->name; + void *kvalue = NULL; if (ctx->size) { if (ctx->size > XATTR_SIZE_MAX) ctx->size = XATTR_SIZE_MAX; - ctx->kvalue = kvzalloc(ctx->size, GFP_KERNEL); - if (!ctx->kvalue) + kvalue = kvzalloc(ctx->size, GFP_KERNEL); + if (!kvalue) return -ENOMEM; } - if (is_posix_acl_xattr(ctx->kname->name)) - error = do_get_acl(idmap, d, kname, ctx->kvalue, ctx->size); + if (is_posix_acl_xattr(kname)) + error = do_get_acl(idmap, d, kname, kvalue, ctx->size); else - error = vfs_getxattr(idmap, d, kname, ctx->kvalue, ctx->size); + error = vfs_getxattr(idmap, d, kname, kvalue, ctx->size); if (error > 0) { - if (ctx->size && copy_to_user(ctx->value, ctx->kvalue, error)) + if (ctx->size && copy_to_user(ctx->value, kvalue, error)) error = -EFAULT; } else if (error == -ERANGE && ctx->size >= XATTR_SIZE_MAX) { /* The file system tried to returned a value bigger @@ -746,79 +794,114 @@ do_getxattr(struct mnt_idmap *idmap, struct dentry *d, error = -E2BIG; } + kvfree(kvalue); return error; } -static ssize_t -getxattr(struct mnt_idmap *idmap, struct dentry *d, - const char __user *name, void __user *value, size_t size) +ssize_t file_getxattr(struct file *f, struct kernel_xattr_ctx *ctx) { + audit_file(f); + return do_getxattr(file_mnt_idmap(f), f->f_path.dentry, ctx); +} + +/* unconditionally consumes filename */ +ssize_t filename_getxattr(int dfd, struct filename *filename, + unsigned int lookup_flags, struct kernel_xattr_ctx *ctx) +{ + struct path path; ssize_t error; +retry: + error = filename_lookup(dfd, filename, lookup_flags, &path, NULL); + if (error) + goto out; + error = do_getxattr(mnt_idmap(path.mnt), path.dentry, ctx); + path_put(&path); + if (retry_estale(error, lookup_flags)) { + lookup_flags |= LOOKUP_REVAL; + goto retry; + } +out: + putname(filename); + return error; +} + +static ssize_t path_getxattrat(int dfd, const char __user *pathname, + unsigned int at_flags, const char __user *name, + void __user *value, size_t size) +{ struct xattr_name kname; - struct xattr_ctx ctx = { + struct kernel_xattr_ctx ctx = { .value = value, - .kvalue = NULL, .size = size, .kname = &kname, .flags = 0, }; + struct filename *filename; + ssize_t error; - error = strncpy_from_user(kname.name, name, sizeof(kname.name)); - if (error == 0 || error == sizeof(kname.name)) - error = -ERANGE; - if (error < 0) - return error; + if ((at_flags & ~(AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH)) != 0) + return -EINVAL; - error = do_getxattr(idmap, d, &ctx); + error = import_xattr_name(&kname, name); + if (error) + return error; - kvfree(ctx.kvalue); - return error; + filename = getname_maybe_null(pathname, at_flags); + if (!filename) { + CLASS(fd, f)(dfd); + if (fd_empty(f)) + return -EBADF; + return file_getxattr(fd_file(f), &ctx); + } else { + int lookup_flags = 0; + if (!(at_flags & AT_SYMLINK_NOFOLLOW)) + lookup_flags = LOOKUP_FOLLOW; + return filename_getxattr(dfd, filename, lookup_flags, &ctx); + } } -static ssize_t path_getxattr(const char __user *pathname, - const char __user *name, void __user *value, - size_t size, unsigned int lookup_flags) +SYSCALL_DEFINE6(getxattrat, int, dfd, const char __user *, pathname, unsigned int, at_flags, + const char __user *, name, struct xattr_args __user *, uargs, size_t, usize) { - struct path path; - ssize_t error; -retry: - error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path); + struct xattr_args args = {}; + int error; + + BUILD_BUG_ON(sizeof(struct xattr_args) < XATTR_ARGS_SIZE_VER0); + BUILD_BUG_ON(sizeof(struct xattr_args) != XATTR_ARGS_SIZE_LATEST); + + if (unlikely(usize < XATTR_ARGS_SIZE_VER0)) + return -EINVAL; + if (usize > PAGE_SIZE) + return -E2BIG; + + error = copy_struct_from_user(&args, sizeof(args), uargs, usize); if (error) return error; - error = getxattr(mnt_idmap(path.mnt), path.dentry, name, value, size); - path_put(&path); - if (retry_estale(error, lookup_flags)) { - lookup_flags |= LOOKUP_REVAL; - goto retry; - } - return error; + + if (args.flags != 0) + return -EINVAL; + + return path_getxattrat(dfd, pathname, at_flags, name, + u64_to_user_ptr(args.value), args.size); } SYSCALL_DEFINE4(getxattr, const char __user *, pathname, const char __user *, name, void __user *, value, size_t, size) { - return path_getxattr(pathname, name, value, size, LOOKUP_FOLLOW); + return path_getxattrat(AT_FDCWD, pathname, 0, name, value, size); } SYSCALL_DEFINE4(lgetxattr, const char __user *, pathname, const char __user *, name, void __user *, value, size_t, size) { - return path_getxattr(pathname, name, value, size, 0); + return path_getxattrat(AT_FDCWD, pathname, AT_SYMLINK_NOFOLLOW, name, + value, size); } SYSCALL_DEFINE4(fgetxattr, int, fd, const char __user *, name, void __user *, value, size_t, size) { - struct fd f = fdget(fd); - ssize_t error = -EBADF; - - if (!fd_file(f)) - return error; - audit_file(fd_file(f)); - error = getxattr(file_mnt_idmap(fd_file(f)), fd_file(f)->f_path.dentry, - name, value, size); - fdput(f); - return error; + return path_getxattrat(fd, NULL, AT_EMPTY_PATH, name, value, size); } /* @@ -853,47 +936,80 @@ listxattr(struct dentry *d, char __user *list, size_t size) return error; } -static ssize_t path_listxattr(const char __user *pathname, char __user *list, - size_t size, unsigned int lookup_flags) +static +ssize_t file_listxattr(struct file *f, char __user *list, size_t size) +{ + audit_file(f); + return listxattr(f->f_path.dentry, list, size); +} + +/* unconditionally consumes filename */ +static +ssize_t filename_listxattr(int dfd, struct filename *filename, + unsigned int lookup_flags, + char __user *list, size_t size) { struct path path; ssize_t error; retry: - error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path); + error = filename_lookup(dfd, filename, lookup_flags, &path, NULL); if (error) - return error; + goto out; error = listxattr(path.dentry, list, size); path_put(&path); if (retry_estale(error, lookup_flags)) { lookup_flags |= LOOKUP_REVAL; goto retry; } +out: + putname(filename); return error; } +static ssize_t path_listxattrat(int dfd, const char __user *pathname, + unsigned int at_flags, char __user *list, + size_t size) +{ + struct filename *filename; + int lookup_flags; + + if ((at_flags & ~(AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH)) != 0) + return -EINVAL; + + filename = getname_maybe_null(pathname, at_flags); + if (!filename) { + CLASS(fd, f)(dfd); + if (fd_empty(f)) + return -EBADF; + return file_listxattr(fd_file(f), list, size); + } + + lookup_flags = (at_flags & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW; + return filename_listxattr(dfd, filename, lookup_flags, list, size); +} + +SYSCALL_DEFINE5(listxattrat, int, dfd, const char __user *, pathname, + unsigned int, at_flags, + char __user *, list, size_t, size) +{ + return path_listxattrat(dfd, pathname, at_flags, list, size); +} + SYSCALL_DEFINE3(listxattr, const char __user *, pathname, char __user *, list, size_t, size) { - return path_listxattr(pathname, list, size, LOOKUP_FOLLOW); + return path_listxattrat(AT_FDCWD, pathname, 0, list, size); } SYSCALL_DEFINE3(llistxattr, const char __user *, pathname, char __user *, list, size_t, size) { - return path_listxattr(pathname, list, size, 0); + return path_listxattrat(AT_FDCWD, pathname, AT_SYMLINK_NOFOLLOW, list, size); } SYSCALL_DEFINE3(flistxattr, int, fd, char __user *, list, size_t, size) { - struct fd f = fdget(fd); - ssize_t error = -EBADF; - - if (!fd_file(f)) - return error; - audit_file(fd_file(f)); - error = listxattr(fd_file(f)->f_path.dentry, list, size); - fdput(f); - return error; + return path_listxattrat(fd, NULL, AT_EMPTY_PATH, list, size); } /* @@ -907,25 +1023,33 @@ removexattr(struct mnt_idmap *idmap, struct dentry *d, const char *name) return vfs_removexattr(idmap, d, name); } -static int path_removexattr(const char __user *pathname, - const char __user *name, unsigned int lookup_flags) +static int file_removexattr(struct file *f, struct xattr_name *kname) +{ + int error = mnt_want_write_file(f); + + if (!error) { + audit_file(f); + error = removexattr(file_mnt_idmap(f), + f->f_path.dentry, kname->name); + mnt_drop_write_file(f); + } + return error; +} + +/* unconditionally consumes filename */ +static int filename_removexattr(int dfd, struct filename *filename, + unsigned int lookup_flags, struct xattr_name *kname) { struct path path; int error; - char kname[XATTR_NAME_MAX + 1]; - error = strncpy_from_user(kname, name, sizeof(kname)); - if (error == 0 || error == sizeof(kname)) - error = -ERANGE; - if (error < 0) - return error; retry: - error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path); + error = filename_lookup(dfd, filename, lookup_flags, &path, NULL); if (error) - return error; + goto out; error = mnt_want_write(path.mnt); if (!error) { - error = removexattr(mnt_idmap(path.mnt), path.dentry, kname); + error = removexattr(mnt_idmap(path.mnt), path.dentry, kname->name); mnt_drop_write(path.mnt); } path_put(&path); @@ -933,45 +1057,58 @@ retry: lookup_flags |= LOOKUP_REVAL; goto retry; } +out: + putname(filename); return error; } +static int path_removexattrat(int dfd, const char __user *pathname, + unsigned int at_flags, const char __user *name) +{ + struct xattr_name kname; + struct filename *filename; + unsigned int lookup_flags; + int error; + + if ((at_flags & ~(AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH)) != 0) + return -EINVAL; + + error = import_xattr_name(&kname, name); + if (error) + return error; + + filename = getname_maybe_null(pathname, at_flags); + if (!filename) { + CLASS(fd, f)(dfd); + if (fd_empty(f)) + return -EBADF; + return file_removexattr(fd_file(f), &kname); + } + lookup_flags = (at_flags & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW; + return filename_removexattr(dfd, filename, lookup_flags, &kname); +} + +SYSCALL_DEFINE4(removexattrat, int, dfd, const char __user *, pathname, + unsigned int, at_flags, const char __user *, name) +{ + return path_removexattrat(dfd, pathname, at_flags, name); +} + SYSCALL_DEFINE2(removexattr, const char __user *, pathname, const char __user *, name) { - return path_removexattr(pathname, name, LOOKUP_FOLLOW); + return path_removexattrat(AT_FDCWD, pathname, 0, name); } SYSCALL_DEFINE2(lremovexattr, const char __user *, pathname, const char __user *, name) { - return path_removexattr(pathname, name, 0); + return path_removexattrat(AT_FDCWD, pathname, AT_SYMLINK_NOFOLLOW, name); } SYSCALL_DEFINE2(fremovexattr, int, fd, const char __user *, name) { - struct fd f = fdget(fd); - char kname[XATTR_NAME_MAX + 1]; - int error = -EBADF; - - if (!fd_file(f)) - return error; - audit_file(fd_file(f)); - - error = strncpy_from_user(kname, name, sizeof(kname)); - if (error == 0 || error == sizeof(kname)) - error = -ERANGE; - if (error < 0) - return error; - - error = mnt_want_write_file(fd_file(f)); - if (!error) { - error = removexattr(file_mnt_idmap(fd_file(f)), - fd_file(f)->f_path.dentry, kname); - mnt_drop_write_file(fd_file(f)); - } - fdput(f); - return error; + return path_removexattrat(fd, NULL, AT_EMPTY_PATH, name); } int xattr_list_one(char **buffer, ssize_t *remaining_size, const char *name) @@ -1005,9 +1142,10 @@ generic_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size) { const struct xattr_handler *handler, * const *handlers = dentry->d_sb->s_xattr; ssize_t remaining_size = buffer_size; - int err = 0; for_each_xattr_handler(handlers, handler) { + int err; + if (!handler->name || (handler->list && !handler->list(dentry))) continue; err = xattr_list_one(&buffer, &remaining_size, handler->name); @@ -1015,7 +1153,7 @@ generic_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size) return err; } - return err ? err : buffer_size - remaining_size; + return buffer_size - remaining_size; } EXPORT_SYMBOL(generic_listxattr); |