Messages in this thread | | | Date | Fri, 27 Jun 2008 15:59:05 -0500 | From | "Serge E. Hallyn" <> | Subject | Re: [PATCH 2/4] security: filesystem capabilities bugfix2 |
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Quoting Andrew G. Morgan (morgan@kernel.org): > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > Bugfix for strace, and CAP_SETPCAP, in the case that filesystem > capabilities are supported. > -----BEGIN PGP SIGNATURE----- > Version: GnuPG v1.2.6 (GNU/Linux) > > iD8DBQFIY1fr+bHCR3gb8jsRAph7AKDOlmeveIpQs1jhIs0TJxjCdMAS5ACgsml6 > 7UYR+FZpW2XdmG8PkiZzemU= > =+Ko+ > -----END PGP SIGNATURE-----
> From f4419c78fff77c4fa3cdfa6b0a78edae92ddf467 Mon Sep 17 00:00:00 2001 > From: Andrew G. Morgan <morgan@kernel.org> > Date: Wed, 25 Jun 2008 23:24:10 -0700 > Subject: [PATCH] Blunt CAP_SETPCAP on strace with filesystem capability support > > The filesystem capability support meaning for CAP_SETPCAP is less > powerful than the non-filesystem capability support. As such, when > filesystem capabilities are configured, we should not permit > CAP_SETPCAP to 'enhance' the current process through strace > manipulation of a child process. > > Signed-off-by: Andrew G. Morgan <morgan@kernel.org>
If I understand this right, then LSM_UNSAFE_PTRACE_CAP will only be set if the tracer didn't have CAP_SYS_PTRACE. So this seems sane to me.
Acked-by: Serge Hallyn <serue@us.ibm.com>
> --- > security/commoncap.c | 13 ++++++++++--- > 1 files changed, 10 insertions(+), 3 deletions(-) > > diff --git a/security/commoncap.c b/security/commoncap.c > index 5edabc7..a9ea921 100644 > --- a/security/commoncap.c > +++ b/security/commoncap.c > @@ -103,10 +103,16 @@ static inline int cap_inh_is_capped(void) > return (cap_capable(current, CAP_SETPCAP) != 0); > } > > +static inline int cap_limit_straced_target(void) { return 1; } > + > #else /* ie., ndef CONFIG_SECURITY_FILE_CAPABILITIES */ > > static inline int cap_block_setpcap(struct task_struct *t) { return 0; } > static inline int cap_inh_is_capped(void) { return 1; } > +static inline int cap_limit_straced_target(void) > +{ > + return !capable(CAP_SETPCAP); > +} > > #endif /* def CONFIG_SECURITY_FILE_CAPABILITIES */ > > @@ -342,9 +348,10 @@ void cap_bprm_apply_creds (struct linux_binprm *bprm, int unsafe) > bprm->e_uid = current->uid; > bprm->e_gid = current->gid; > } > - if (!capable (CAP_SETPCAP)) { > - new_permitted = cap_intersect (new_permitted, > - current->cap_permitted); > + if (cap_limit_straced_target()) { > + new_permitted = > + cap_intersect(new_permitted, > + current->cap_permitted); > } > } > } > -- > 1.5.3.7 >
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