On Mon, Mar 9, 2020 at 12:41 PM Richard Haines <richard_c_haines@xxxxxxxxxxxxxx> wrote: > > On Mon, 2020-03-09 at 09:35 -0400, Stephen Smalley wrote: > > 1. Mount the same filesystem twice with two different sets of context > > mount options, check that mount(2) fails with errno EINVAL. > > I've tests for the first part already, however with NFS it returns > EBUSY (using mount(2) or the fixed fsconfig(2)). On ext4, xfs & vfat it > does return EINVAL. I guess another NFS bug. Also mount(8) ignores the > error and just carries on. Here is a test using the testsuite mount(2): Looks like selinux_cmp_sb_context() returns -EBUSY on error instead of -EINVAL. This goes back to 094f7b69ea738d7d619cba449d2af97159949459 ("selinux: make security_sb_clone_mnt_opts return an error on context mismatch"). I guess you can just make the test accept either -EINVAL or -EBUSY for the time being and we'll have to consider whether we want to change it and what would break if we did.