| Message ID | 1500416736-49829-3-git-send-email-keescook@chromium.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 07/18/2017 03:25 PM, Kees Cook wrote: > The cred_prepared bprm flag has a misleading name. It has nothing to do > with the bprm_prepare_cred hook, and actually tracks if bprm_set_creds has > been called. Rename this flag and improve its comment. > > Cc: David Howells <dhowells@redhat.com> > Cc: John Johansen <john.johansen@canonical.com> > Cc: Paul Moore <paul@paul-moore.com> > Cc: Stephen Smalley <sds@tycho.nsa.gov> > Cc: Casey Schaufler <casey@schaufler-ca.com> > Cc: James Morris <james.l.morris@oracle.com> > Signed-off-by: Kees Cook <keescook@chromium.org> looks good Acked-by: John Johansen <john.johansen@canonical.com> > --- > fs/binfmt_flat.c | 2 +- > fs/exec.c | 2 +- > include/linux/binfmts.h | 8 ++++++-- > security/apparmor/domain.c | 2 +- > security/selinux/hooks.c | 2 +- > security/smack/smack_lsm.c | 2 +- > security/tomoyo/tomoyo.c | 2 +- > 7 files changed, 12 insertions(+), 8 deletions(-) > > diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c > index 2edcefc0a294..a722530cc468 100644 > --- a/fs/binfmt_flat.c > +++ b/fs/binfmt_flat.c > @@ -885,7 +885,7 @@ static int load_flat_shared_library(int id, struct lib_info *libs) > * as we're past the point of no return and are dealing with shared > * libraries. > */ > - bprm.cred_prepared = 1; > + bprm.called_set_creds = 1; > > res = prepare_binprm(&bprm); > > diff --git a/fs/exec.c b/fs/exec.c > index 904199086490..925c85a45d97 100644 > --- a/fs/exec.c > +++ b/fs/exec.c > @@ -1547,7 +1547,7 @@ int prepare_binprm(struct linux_binprm *bprm) > retval = security_bprm_set_creds(bprm); > if (retval) > return retval; > - bprm->cred_prepared = 1; > + bprm->called_set_creds = 1; > > memset(bprm->buf, 0, BINPRM_BUF_SIZE); > return kernel_read(bprm->file, 0, bprm->buf, BINPRM_BUF_SIZE); > diff --git a/include/linux/binfmts.h b/include/linux/binfmts.h > index 9508b5f83c7e..36be5a67517a 100644 > --- a/include/linux/binfmts.h > +++ b/include/linux/binfmts.h > @@ -25,8 +25,12 @@ struct linux_binprm { > struct mm_struct *mm; > unsigned long p; /* current top of mem */ > unsigned int > - cred_prepared:1,/* true if creds already prepared (multiple > - * preps happen for interpreters) */ > + /* > + * True after the bprm_set_creds hook has been called once > + * (multiple calls can be made via prepare_binprm() for > + * binfmt_script/misc). > + */ > + called_set_creds:1, > cap_effective:1,/* true if has elevated effective capabilities, > * false if not; except for init which inherits > * its parent's caps anyway */ > diff --git a/security/apparmor/domain.c b/security/apparmor/domain.c > index 001e133a3c8c..878407e023e3 100644 > --- a/security/apparmor/domain.c > +++ b/security/apparmor/domain.c > @@ -350,7 +350,7 @@ int apparmor_bprm_set_creds(struct linux_binprm *bprm) > const char *name = NULL, *info = NULL; > int error = 0; > > - if (bprm->cred_prepared) > + if (bprm->called_set_creds) > return 0; > > ctx = cred_ctx(bprm->cred); > diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c > index 819fd6858b49..0f1450a06b02 100644 > --- a/security/selinux/hooks.c > +++ b/security/selinux/hooks.c > @@ -2327,7 +2327,7 @@ static int selinux_bprm_set_creds(struct linux_binprm *bprm) > > /* SELinux context only depends on initial program or script and not > * the script interpreter */ > - if (bprm->cred_prepared) > + if (bprm->called_set_creds) > return 0; > > old_tsec = current_security(); > diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c > index 658f5d8c7e76..7d4b2e221124 100644 > --- a/security/smack/smack_lsm.c > +++ b/security/smack/smack_lsm.c > @@ -917,7 +917,7 @@ static int smack_bprm_set_creds(struct linux_binprm *bprm) > struct superblock_smack *sbsp; > int rc; > > - if (bprm->cred_prepared) > + if (bprm->called_set_creds) > return 0; > > isp = inode->i_security; > diff --git a/security/tomoyo/tomoyo.c b/security/tomoyo/tomoyo.c > index 130b4fa4f65f..d25b705360e0 100644 > --- a/security/tomoyo/tomoyo.c > +++ b/security/tomoyo/tomoyo.c > @@ -76,7 +76,7 @@ static int tomoyo_bprm_set_creds(struct linux_binprm *bprm) > * Do only if this function is called for the first time of an execve > * operation. > */ > - if (bprm->cred_prepared) > + if (bprm->called_set_creds) > return 0; > #ifndef CONFIG_SECURITY_TOMOYO_OMIT_USERSPACE_LOADER > /* > -- To unsubscribe from this list: send the line "unsubscribe linux-security-module" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, Jul 18, 2017 at 3:25 PM, Kees Cook <keescook@chromium.org> wrote: > The cred_prepared bprm flag has a misleading name. It has nothing to do > with the bprm_prepare_cred hook, and actually tracks if bprm_set_creds has > been called. Rename this flag and improve its comment. > > Cc: David Howells <dhowells@redhat.com> > Cc: John Johansen <john.johansen@canonical.com> > Cc: Paul Moore <paul@paul-moore.com> > Cc: Stephen Smalley <sds@tycho.nsa.gov> > Cc: Casey Schaufler <casey@schaufler-ca.com> > Cc: James Morris <james.l.morris@oracle.com> > Signed-off-by: Kees Cook <keescook@chromium.org> > --- > fs/binfmt_flat.c | 2 +- > fs/exec.c | 2 +- > include/linux/binfmts.h | 8 ++++++-- > security/apparmor/domain.c | 2 +- > security/selinux/hooks.c | 2 +- > security/smack/smack_lsm.c | 2 +- > security/tomoyo/tomoyo.c | 2 +- > 7 files changed, 12 insertions(+), 8 deletions(-) > > diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c > index 2edcefc0a294..a722530cc468 100644 > --- a/fs/binfmt_flat.c > +++ b/fs/binfmt_flat.c > @@ -885,7 +885,7 @@ static int load_flat_shared_library(int id, struct lib_info *libs) > * as we're past the point of no return and are dealing with shared > * libraries. > */ > - bprm.cred_prepared = 1; > + bprm.called_set_creds = 1; WTF is this? It's not, strictly speaking, a bug in this patch, but it's nonsensical. Is it fixed (presuably deleted) later? Otherwise looks good. -- To unsubscribe from this list: send the line "unsubscribe linux-security-module" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, Jul 18, 2017 at 6:06 PM, Andy Lutomirski <luto@kernel.org> wrote: > On Tue, Jul 18, 2017 at 3:25 PM, Kees Cook <keescook@chromium.org> wrote: >> The cred_prepared bprm flag has a misleading name. It has nothing to do >> with the bprm_prepare_cred hook, and actually tracks if bprm_set_creds has >> been called. Rename this flag and improve its comment. >> >> Cc: David Howells <dhowells@redhat.com> >> Cc: John Johansen <john.johansen@canonical.com> >> Cc: Paul Moore <paul@paul-moore.com> >> Cc: Stephen Smalley <sds@tycho.nsa.gov> >> Cc: Casey Schaufler <casey@schaufler-ca.com> >> Cc: James Morris <james.l.morris@oracle.com> >> Signed-off-by: Kees Cook <keescook@chromium.org> >> --- >> fs/binfmt_flat.c | 2 +- >> fs/exec.c | 2 +- >> include/linux/binfmts.h | 8 ++++++-- >> security/apparmor/domain.c | 2 +- >> security/selinux/hooks.c | 2 +- >> security/smack/smack_lsm.c | 2 +- >> security/tomoyo/tomoyo.c | 2 +- >> 7 files changed, 12 insertions(+), 8 deletions(-) >> >> diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c >> index 2edcefc0a294..a722530cc468 100644 >> --- a/fs/binfmt_flat.c >> +++ b/fs/binfmt_flat.c >> @@ -885,7 +885,7 @@ static int load_flat_shared_library(int id, struct lib_info *libs) >> * as we're past the point of no return and are dealing with shared >> * libraries. >> */ >> - bprm.cred_prepared = 1; >> + bprm.called_set_creds = 1; > > WTF is this? It's not, strictly speaking, a bug in this patch, but > it's nonsensical. Is it fixed (presuably deleted) later? binfmt_flat looks crazy, but I haven't seen any distros that enable it. > Otherwise looks good. Thanks! -Kees
On Tue, 18 Jul 2017, Kees Cook wrote: > The cred_prepared bprm flag has a misleading name. It has nothing to do > with the bprm_prepare_cred hook, and actually tracks if bprm_set_creds has > been called. Rename this flag and improve its comment. > > Cc: David Howells <dhowells@redhat.com> > Cc: John Johansen <john.johansen@canonical.com> > Cc: Paul Moore <paul@paul-moore.com> > Cc: Stephen Smalley <sds@tycho.nsa.gov> > Cc: Casey Schaufler <casey@schaufler-ca.com> > Cc: James Morris <james.l.morris@oracle.com> > Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: James Morris <james.l.morris@oracle.com>
On Tue, Jul 18, 2017 at 6:25 PM, Kees Cook <keescook@chromium.org> wrote: > The cred_prepared bprm flag has a misleading name. It has nothing to do > with the bprm_prepare_cred hook, and actually tracks if bprm_set_creds has > been called. Rename this flag and improve its comment. > > Cc: David Howells <dhowells@redhat.com> > Cc: John Johansen <john.johansen@canonical.com> > Cc: Paul Moore <paul@paul-moore.com> > Cc: Stephen Smalley <sds@tycho.nsa.gov> > Cc: Casey Schaufler <casey@schaufler-ca.com> > Cc: James Morris <james.l.morris@oracle.com> > Signed-off-by: Kees Cook <keescook@chromium.org> > --- > fs/binfmt_flat.c | 2 +- > fs/exec.c | 2 +- > include/linux/binfmts.h | 8 ++++++-- > security/apparmor/domain.c | 2 +- > security/selinux/hooks.c | 2 +- > security/smack/smack_lsm.c | 2 +- > security/tomoyo/tomoyo.c | 2 +- > 7 files changed, 12 insertions(+), 8 deletions(-) Acked-by: Paul Moore <paul@paul-moore.com>
diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c index 2edcefc0a294..a722530cc468 100644 --- a/fs/binfmt_flat.c +++ b/fs/binfmt_flat.c @@ -885,7 +885,7 @@ static int load_flat_shared_library(int id, struct lib_info *libs) * as we're past the point of no return and are dealing with shared * libraries. */ - bprm.cred_prepared = 1; + bprm.called_set_creds = 1; res = prepare_binprm(&bprm); diff --git a/fs/exec.c b/fs/exec.c index 904199086490..925c85a45d97 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1547,7 +1547,7 @@ int prepare_binprm(struct linux_binprm *bprm) retval = security_bprm_set_creds(bprm); if (retval) return retval; - bprm->cred_prepared = 1; + bprm->called_set_creds = 1; memset(bprm->buf, 0, BINPRM_BUF_SIZE); return kernel_read(bprm->file, 0, bprm->buf, BINPRM_BUF_SIZE); diff --git a/include/linux/binfmts.h b/include/linux/binfmts.h index 9508b5f83c7e..36be5a67517a 100644 --- a/include/linux/binfmts.h +++ b/include/linux/binfmts.h @@ -25,8 +25,12 @@ struct linux_binprm { struct mm_struct *mm; unsigned long p; /* current top of mem */ unsigned int - cred_prepared:1,/* true if creds already prepared (multiple - * preps happen for interpreters) */ + /* + * True after the bprm_set_creds hook has been called once + * (multiple calls can be made via prepare_binprm() for + * binfmt_script/misc). + */ + called_set_creds:1, cap_effective:1,/* true if has elevated effective capabilities, * false if not; except for init which inherits * its parent's caps anyway */ diff --git a/security/apparmor/domain.c b/security/apparmor/domain.c index 001e133a3c8c..878407e023e3 100644 --- a/security/apparmor/domain.c +++ b/security/apparmor/domain.c @@ -350,7 +350,7 @@ int apparmor_bprm_set_creds(struct linux_binprm *bprm) const char *name = NULL, *info = NULL; int error = 0; - if (bprm->cred_prepared) + if (bprm->called_set_creds) return 0; ctx = cred_ctx(bprm->cred); diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 819fd6858b49..0f1450a06b02 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -2327,7 +2327,7 @@ static int selinux_bprm_set_creds(struct linux_binprm *bprm) /* SELinux context only depends on initial program or script and not * the script interpreter */ - if (bprm->cred_prepared) + if (bprm->called_set_creds) return 0; old_tsec = current_security(); diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index 658f5d8c7e76..7d4b2e221124 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -917,7 +917,7 @@ static int smack_bprm_set_creds(struct linux_binprm *bprm) struct superblock_smack *sbsp; int rc; - if (bprm->cred_prepared) + if (bprm->called_set_creds) return 0; isp = inode->i_security; diff --git a/security/tomoyo/tomoyo.c b/security/tomoyo/tomoyo.c index 130b4fa4f65f..d25b705360e0 100644 --- a/security/tomoyo/tomoyo.c +++ b/security/tomoyo/tomoyo.c @@ -76,7 +76,7 @@ static int tomoyo_bprm_set_creds(struct linux_binprm *bprm) * Do only if this function is called for the first time of an execve * operation. */ - if (bprm->cred_prepared) + if (bprm->called_set_creds) return 0; #ifndef CONFIG_SECURITY_TOMOYO_OMIT_USERSPACE_LOADER /*
The cred_prepared bprm flag has a misleading name. It has nothing to do with the bprm_prepare_cred hook, and actually tracks if bprm_set_creds has been called. Rename this flag and improve its comment. Cc: David Howells <dhowells@redhat.com> Cc: John Johansen <john.johansen@canonical.com> Cc: Paul Moore <paul@paul-moore.com> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: Casey Schaufler <casey@schaufler-ca.com> Cc: James Morris <james.l.morris@oracle.com> Signed-off-by: Kees Cook <keescook@chromium.org> --- fs/binfmt_flat.c | 2 +- fs/exec.c | 2 +- include/linux/binfmts.h | 8 ++++++-- security/apparmor/domain.c | 2 +- security/selinux/hooks.c | 2 +- security/smack/smack_lsm.c | 2 +- security/tomoyo/tomoyo.c | 2 +- 7 files changed, 12 insertions(+), 8 deletions(-)