On Wed 01-06-16 23:12:20, Tetsuo Handa wrote: > Michal Hocko wrote: > > vforked tasks are not really sitting on any memory. They are sharing > > the mm with parent until they exec into a new code. Until then it is > > just pinning the address space. OOM killer will kill the vforked task > > along with its parent but we still can end up selecting vforked task > > when the parent wouldn't be selected. E.g. init doing vfork to launch > > a task or vforked being a child of oom unkillable task with an updated > > oom_score_adj to be killable. > > > > Make sure to not select vforked task as an oom victim by checking > > vfork_done in oom_badness. > > While vfork()ed task cannot modify userspace memory, can't such task > allocate significant amount of kernel memory inside execve() operation > (as demonstrated by CVE-2010-4243 64bit_dos.c )? > > It is possible that killing vfork()ed task releases a lot of memory, > isn't it? I am not familiar with the above CVE but doesn't that allocated memory come after flush_old_exec (and so mm_release)? -- Michal Hocko SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>