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-rw-r--r--fs/fuse/dir.c91
-rw-r--r--fs/fuse/fuse_i.h3
-rw-r--r--fs/fuse/inode.c5
-rw-r--r--include/uapi/linux/fuse.h34
4 files changed, 130 insertions, 3 deletions
diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index 0654bfedcbb0..656e921f3506 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -17,6 +17,9 @@
#include <linux/xattr.h>
#include <linux/iversion.h>
#include <linux/posix_acl.h>
+#include <linux/security.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
static void fuse_advise_use_readdirplus(struct inode *dir)
{
@@ -456,6 +459,62 @@ static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry,
return ERR_PTR(err);
}
+static int get_security_context(struct dentry *entry, umode_t mode,
+ void **security_ctx, u32 *security_ctxlen)
+{
+ struct fuse_secctx *fctx;
+ struct fuse_secctx_header *header;
+ void *ctx = NULL, *ptr;
+ u32 ctxlen, total_len = sizeof(*header);
+ int err, nr_ctx = 0;
+ const char *name;
+ size_t namelen;
+
+ err = security_dentry_init_security(entry, mode, &entry->d_name,
+ &name, &ctx, &ctxlen);
+ if (err) {
+ if (err != -EOPNOTSUPP)
+ goto out_err;
+ /* No LSM is supporting this security hook. Ignore error */
+ ctxlen = 0;
+ ctx = NULL;
+ }
+
+ if (ctxlen) {
+ nr_ctx = 1;
+ namelen = strlen(name) + 1;
+ err = -EIO;
+ if (WARN_ON(namelen > XATTR_NAME_MAX + 1 || ctxlen > S32_MAX))
+ goto out_err;
+ total_len += FUSE_REC_ALIGN(sizeof(*fctx) + namelen + ctxlen);
+ }
+
+ err = -ENOMEM;
+ header = ptr = kzalloc(total_len, GFP_KERNEL);
+ if (!ptr)
+ goto out_err;
+
+ header->nr_secctx = nr_ctx;
+ header->size = total_len;
+ ptr += sizeof(*header);
+ if (nr_ctx) {
+ fctx = ptr;
+ fctx->size = ctxlen;
+ ptr += sizeof(*fctx);
+
+ strcpy(ptr, name);
+ ptr += namelen;
+
+ memcpy(ptr, ctx, ctxlen);
+ }
+ *security_ctxlen = total_len;
+ *security_ctx = header;
+ err = 0;
+out_err:
+ kfree(ctx);
+ return err;
+}
+
/*
* Atomic create+open operation
*
@@ -476,6 +535,8 @@ static int fuse_create_open(struct inode *dir, struct dentry *entry,
struct fuse_entry_out outentry;
struct fuse_inode *fi;
struct fuse_file *ff;
+ void *security_ctx = NULL;
+ u32 security_ctxlen;
/* Userspace expects S_IFREG in create mode */
BUG_ON((mode & S_IFMT) != S_IFREG);
@@ -517,7 +578,20 @@ static int fuse_create_open(struct inode *dir, struct dentry *entry,
args.out_args[0].value = &outentry;
args.out_args[1].size = sizeof(outopen);
args.out_args[1].value = &outopen;
+
+ if (fm->fc->init_security) {
+ err = get_security_context(entry, mode, &security_ctx,
+ &security_ctxlen);
+ if (err)
+ goto out_put_forget_req;
+
+ args.in_numargs = 3;
+ args.in_args[2].size = security_ctxlen;
+ args.in_args[2].value = security_ctx;
+ }
+
err = fuse_simple_request(fm, &args);
+ kfree(security_ctx);
if (err)
goto out_free_ff;
@@ -620,6 +694,8 @@ static int create_new_entry(struct fuse_mount *fm, struct fuse_args *args,
struct dentry *d;
int err;
struct fuse_forget_link *forget;
+ void *security_ctx = NULL;
+ u32 security_ctxlen;
if (fuse_is_bad(dir))
return -EIO;
@@ -633,7 +709,22 @@ static int create_new_entry(struct fuse_mount *fm, struct fuse_args *args,
args->out_numargs = 1;
args->out_args[0].size = sizeof(outarg);
args->out_args[0].value = &outarg;
+
+ if (fm->fc->init_security && args->opcode != FUSE_LINK) {
+ err = get_security_context(entry, mode, &security_ctx,
+ &security_ctxlen);
+ if (err)
+ goto out_put_forget_req;
+
+ BUG_ON(args->in_numargs != 2);
+
+ args->in_numargs = 3;
+ args->in_args[2].size = security_ctxlen;
+ args->in_args[2].value = security_ctx;
+ }
+
err = fuse_simple_request(fm, args);
+ kfree(security_ctx);
if (err)
goto out_put_forget_req;
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index 198637b41e19..c1a8b313e6ed 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -765,6 +765,9 @@ struct fuse_conn {
/* Propagate syncfs() to server */
unsigned int sync_fs:1;
+ /* Initialize security xattrs when creating a new inode */
+ unsigned int init_security:1;
+
/** The number of requests waiting for completion */
atomic_t num_waiting;
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index 5a1dad8c1f92..63ab45427de5 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -1178,6 +1178,8 @@ static void process_init_reply(struct fuse_mount *fm, struct fuse_args *args,
}
if (flags & FUSE_SETXATTR_EXT)
fc->setxattr_ext = 1;
+ if (flags & FUSE_SECURITY_CTX)
+ fc->init_security = 1;
} else {
ra_pages = fc->max_read / PAGE_SIZE;
fc->no_lock = 1;
@@ -1222,7 +1224,8 @@ void fuse_send_init(struct fuse_mount *fm)
FUSE_PARALLEL_DIROPS | FUSE_HANDLE_KILLPRIV | FUSE_POSIX_ACL |
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_HANDLE_KILLPRIV_V2 | FUSE_SETXATTR_EXT | FUSE_INIT_EXT |
+ FUSE_SECURITY_CTX;
#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 980f3998c11b..3f0ea63fec08 100644
--- a/include/uapi/linux/fuse.h
+++ b/include/uapi/linux/fuse.h
@@ -191,6 +191,8 @@
* 7.36
* - extend fuse_init_in with reserved fields, add FUSE_INIT_EXT init flag
* - add flags2 to fuse_init_in and fuse_init_out
+ * - add FUSE_SECURITY_CTX init flag
+ * - add security context to create, mkdir, symlink, and mknod requests
*/
#ifndef _LINUX_FUSE_H
@@ -347,6 +349,8 @@ struct fuse_file_lock {
* FUSE_SETXATTR_EXT: Server supports extended struct fuse_setxattr_in
* FUSE_INIT_EXT: extended fuse_init_in request
* FUSE_INIT_RESERVED: reserved, do not use
+ * FUSE_SECURITY_CTX: add security context to create, mkdir, symlink, and
+ * mknod
*/
#define FUSE_ASYNC_READ (1 << 0)
#define FUSE_POSIX_LOCKS (1 << 1)
@@ -381,6 +385,7 @@ struct fuse_file_lock {
#define FUSE_INIT_EXT (1 << 30)
#define FUSE_INIT_RESERVED (1 << 31)
/* bits 32..63 get shifted down 32 bits into the flags2 field */
+#define FUSE_SECURITY_CTX (1ULL << 32)
/**
* CUSE INIT request/reply flags
@@ -877,9 +882,12 @@ struct fuse_dirent {
char name[];
};
-#define FUSE_NAME_OFFSET offsetof(struct fuse_dirent, name)
-#define FUSE_DIRENT_ALIGN(x) \
+/* Align variable length records to 64bit boundary */
+#define FUSE_REC_ALIGN(x) \
(((x) + sizeof(uint64_t) - 1) & ~(sizeof(uint64_t) - 1))
+
+#define FUSE_NAME_OFFSET offsetof(struct fuse_dirent, name)
+#define FUSE_DIRENT_ALIGN(x) FUSE_REC_ALIGN(x)
#define FUSE_DIRENT_SIZE(d) \
FUSE_DIRENT_ALIGN(FUSE_NAME_OFFSET + (d)->namelen)
@@ -996,4 +1004,26 @@ struct fuse_syncfs_in {
uint64_t padding;
};
+/*
+ * For each security context, send fuse_secctx with size of security context
+ * fuse_secctx will be followed by security context name and this in turn
+ * will be followed by actual context label.
+ * fuse_secctx, name, context
+ */
+struct fuse_secctx {
+ uint32_t size;
+ uint32_t padding;
+};
+
+/*
+ * Contains the information about how many fuse_secctx structures are being
+ * sent and what's the total size of all security contexts (including
+ * size of fuse_secctx_header).
+ *
+ */
+struct fuse_secctx_header {
+ uint32_t size;
+ uint32_t nr_secctx;
+};
+
#endif /* _LINUX_FUSE_H */
generated by cgit (git 2.34.1) at 2024-06-23 10:25:47 +0000