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charset=us-ascii Content-Disposition: inline In-Reply-To: <20230704153630.1591122-5-revest@chromium.org> X-Rspamd-Queue-Id: 20D652000C X-Rspam-User: X-Stat-Signature: m4c3wjbr31irzd6ecfe48qj9hubnzk6s X-Rspamd-Server: rspam03 X-HE-Tag: 1693141857-384759 X-HE-Meta: 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 3PUMhTr/ 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, Jul 04, 2023 at 05:36:28PM +0200, Florent Revest wrote: > static inline int prctl_set_mdwe(unsigned long bits, unsigned long arg3, > unsigned long arg4, unsigned long arg5) > { > + unsigned long current_bits; > + > if (arg3 || arg4 || arg5) > return -EINVAL; > > - if (bits & ~(PR_MDWE_REFUSE_EXEC_GAIN)) > + if (bits & ~(PR_MDWE_REFUSE_EXEC_GAIN | PR_MDWE_NO_INHERIT)) > + return -EINVAL; > + > + /* NO_INHERIT only makes sense with REFUSE_EXEC_GAIN */ > + if (bits & PR_MDWE_NO_INHERIT && !(bits & PR_MDWE_REFUSE_EXEC_GAIN)) > return -EINVAL; > > + current_bits = get_current_mdwe(); > + if (current_bits && current_bits != bits) > + return -EPERM; /* Cannot unset the flags */ > + > + if (bits & PR_MDWE_NO_INHERIT) > + set_bit(MMF_HAS_MDWE_NO_INHERIT, ¤t->mm->flags); > if (bits & PR_MDWE_REFUSE_EXEC_GAIN) > set_bit(MMF_HAS_MDWE, ¤t->mm->flags); > - else if (test_bit(MMF_HAS_MDWE, ¤t->mm->flags)) > - return -EPERM; /* Cannot unset the flag */ > > return 0; > } This works for me, it's easier to read. I don't expect a use-case where the app starts with MDWE no-inherit, forks some new processes and wants to turn inherit on for further forking. > @@ -2384,9 +2406,7 @@ static inline int prctl_get_mdwe(unsigned long arg2, unsigned long arg3, > { > if (arg2 || arg3 || arg4 || arg5) > return -EINVAL; > - > - return test_bit(MMF_HAS_MDWE, ¤t->mm->flags) ? > - PR_MDWE_REFUSE_EXEC_GAIN : 0; > + return (int)get_current_mdwe(); Nitpick: the type conversion should be handled by the compiler as prctl_get_mdwe() returns an int already. Reviewed-by: Catalin Marinas