Similar to commit
1ed95281c0c7 ("anon_inode: raise SB_I_NODEV and SB_I_NOEXEC"):
it shouldn't be possible to execute pidfds via
execveat(fd_anon_inode, "", NULL, NULL, AT_EMPTY_PATH)
so raise SB_I_NOEXEC so that no one gets any creative ideas.
Also raise SB_I_NODEV as we don't expect or support any devices on pidfs.
Link: https://lore.kernel.org/20250618-work-pidfs-persistent-v2-1-98f3456fd552@kernel.org
Reviewed-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
if (!ctx)
return -ENOMEM;
+ fc->s_iflags |= SB_I_NOEXEC;
+ fc->s_iflags |= SB_I_NODEV;
ctx->ops = &pidfs_sops;
ctx->eops = &pidfs_export_operations;
ctx->dops = &pidfs_dentry_operations;