@@ -532,6 +532,7 @@ struct fuse_fs_context {
bool no_control:1;
bool no_force_umount:1;
bool legacy_opts_show:1;
+ bool trusted:1;
enum fuse_dax_mode dax_mode;
unsigned int max_read;
unsigned int blksize;
@@ -1779,6 +1779,7 @@ static int fuse_get_tree(struct fs_context *fsc)
fuse_conn_init(fc, fm, fsc->user_ns, &fuse_dev_fiq_ops, NULL);
fc->release = fuse_free_conn;
+ fc->trusted = ctx->trusted;
fsc->s_fs_info = fm;
@@ -1840,6 +1841,7 @@ static int fuse_init_fs_context(struct fs_context *fsc)
ctx->max_read = ~0;
ctx->blksize = FUSE_DEFAULT_BLKSIZE;
ctx->legacy_opts_show = true;
+ ctx->trusted = uid_eq(current_uid(), GLOBAL_ROOT_UID);
#ifdef CONFIG_BLOCK
if (fsc->fs_type == &fuseblk_fs_type) {
FUSE tends to be installed suid 0: this allows normal users to mount anything, including a program whose read implementation consists of for(;;) sleep(1);, which, if splice were allowed, would sleep forever with the pipe lock held. Normal filesystems can only be mounted by root, and are thus deemed safe. Extend this to when root mounts a FUSE filesystem with an explicit check. Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz> --- fs/fuse/fuse_i.h | 1 + fs/fuse/inode.c | 2 ++ 2 files changed, 3 insertions(+)