On Mon 07-04-25 11:54:19, Christian Brauner wrote: > It isn't possible to execute anoymous inodes because they cannot be ^^ anonymous > opened in any way after they have been created. This includes execution: > > execveat(fd_anon_inode, "", NULL, NULL, AT_EMPTY_PATH) > > Anonymous inodes have inode->f_op set to no_open_fops which sets > no_open() which returns ENXIO. That means any call to do_dentry_open() > which is the endpoint of the do_open_execat() will fail. There's no > chance to execute an anonymous inode. Unless a given subsystem overrides > it ofc. > > Howerver, we should still harden this and raise SB_I_NODEV and ^^^ However > SB_I_NOEXEC on the superblock itself so that no one gets any creative > ideas. ;) Feel free to add: Reviewed-by: Jan Kara <jack@xxxxxxx> Honza > > Cc: <stable@xxxxxxxxxxxxxxx> # all LTS kernels > Signed-off-by: Christian Brauner <brauner@xxxxxxxxxx> > --- > fs/anon_inodes.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/fs/anon_inodes.c b/fs/anon_inodes.c > index cb51a90bece0..e51e7d88980a 100644 > --- a/fs/anon_inodes.c > +++ b/fs/anon_inodes.c > @@ -86,6 +86,8 @@ static int anon_inodefs_init_fs_context(struct fs_context *fc) > struct pseudo_fs_context *ctx = init_pseudo(fc, ANON_INODE_FS_MAGIC); > if (!ctx) > return -ENOMEM; > + fc->s_iflags |= SB_I_NOEXEC; > + fc->s_iflags |= SB_I_NODEV; > ctx->dops = &anon_inodefs_dentry_operations; > return 0; > } > > -- > 2.47.2 > -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR
