On Thu, Oct 08, 2020 at 09:00:21PM +0800, Wen Yang wrote: > After the process exits, the following three dentries still refer to the pid: > /proc/<pid> > /proc/<pid>/ns > /proc/<pid>/ns/pid > > https://bugzilla.kernel.org/show_bug.cgi?id=208613 > > According to the commit f333c700c610 ("pidns: Add a limit on the number of > pid namespaces"), if the pid cannot be released, it may result in the > inability to create a new pid_ns. > > Please backport the following patches to the kernel stable trees (from 4.9.y > to 5.6.y): > 7bc3e6e55acf ("proc: Use a list of inodes to flush from proc") > 26dbc60f385f ("proc: Generalize proc_sys_prune_dcache into proc_prune_siblings_dcache") > f90f3cafe8d5 ("proc: Use d_invalidate in proc_prune_siblings_dcache") > > Signed-off-by: Wen Yang <wenyang@xxxxxxxxxxxxxxxxx> > Cc: Eric W. Biederman <ebiederm@xxxxxxxxxxxx> > Cc: stable@xxxxxxxxxxxxxxx > Cc: linux-kernel@xxxxxxxxxxxxxxx How well did you test these backports? I see at least one fix for them that you missed, odds are there might have been more. Please verify that the above list of patches _really_ is what you want to have applied, and that you have tested it properly. thanks, greg k-h
