| Message ID | 20191224235939.7483-25-casey@schaufler-ca.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | LSM: Module stacking for AppArmor | expand |
On 12/24/19 6:59 PM, Casey Schaufler wrote: > Add an entry /proc/.../attr/context which displays the full > process security "context" in compound format:' > lsm1\0value\0lsm2\0value\0... > This entry is not writable. My takeaway from the earlier exchange with Simon on v12 was that we should either define a new LSM hook for /proc/pid/attr/context that is guaranteed to return a value in a consistent format with SO_PEERCONTEXT or fix AppArmor to return consistent results from its existing getprocattr hook (particularly with respect to the newline character). > > Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> > cc: linux-api@vger.kernel.org > --- > fs/proc/base.c | 1 + > security/security.c | 27 +++++++++++++++++++++++++++ > 2 files changed, 28 insertions(+) > > diff --git a/fs/proc/base.c b/fs/proc/base.c > index 950c200cb9ad..d13c2cf50e4b 100644 > --- a/fs/proc/base.c > +++ b/fs/proc/base.c > @@ -2653,6 +2653,7 @@ static const struct pid_entry attr_dir_stuff[] = { > ATTR(NULL, "keycreate", 0666), > ATTR(NULL, "sockcreate", 0666), > ATTR(NULL, "display", 0666), > + ATTR(NULL, "context", 0666), > #ifdef CONFIG_SECURITY_SMACK > DIR("smack", 0555, > proc_smack_attr_dir_inode_ops, proc_smack_attr_dir_ops), > diff --git a/security/security.c b/security/security.c > index 80539dfd0245..e94de64e114c 100644 > --- a/security/security.c > +++ b/security/security.c > @@ -2099,6 +2099,10 @@ int security_getprocattr(struct task_struct *p, const char *lsm, char *name, > char **value) > { > struct security_hook_list *hp; > + char *final = NULL; > + char *cp; > + int rc = 0; > + int finallen = 0; > int display = lsm_task_display(current); > int slot = 0; > > @@ -2126,6 +2130,29 @@ int security_getprocattr(struct task_struct *p, const char *lsm, char *name, > return -ENOMEM; > } > > + if (!strcmp(name, "context")) { > + hlist_for_each_entry(hp, &security_hook_heads.getprocattr, > + list) { > + rc = hp->hook.getprocattr(p, "current", &cp); > + if (rc == -EINVAL || rc == -ENOPROTOOPT) > + continue; > + if (rc < 0) { > + kfree(final); > + return rc; > + } > + rc = append_ctx(&final, &finallen, hp->lsmid->lsm, > + cp, rc); > + if (rc < 0) { > + kfree(final); > + return rc; > + } > + } > + if (final == NULL) > + return -EINVAL; > + *value = final; > + return finallen; > + } > + > hlist_for_each_entry(hp, &security_hook_heads.getprocattr, list) { > if (lsm != NULL && strcmp(lsm, hp->lsmid->lsm)) > continue; >
diff --git a/fs/proc/base.c b/fs/proc/base.c index 950c200cb9ad..d13c2cf50e4b 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -2653,6 +2653,7 @@ static const struct pid_entry attr_dir_stuff[] = { ATTR(NULL, "keycreate", 0666), ATTR(NULL, "sockcreate", 0666), ATTR(NULL, "display", 0666), + ATTR(NULL, "context", 0666), #ifdef CONFIG_SECURITY_SMACK DIR("smack", 0555, proc_smack_attr_dir_inode_ops, proc_smack_attr_dir_ops), diff --git a/security/security.c b/security/security.c index 80539dfd0245..e94de64e114c 100644 --- a/security/security.c +++ b/security/security.c @@ -2099,6 +2099,10 @@ int security_getprocattr(struct task_struct *p, const char *lsm, char *name, char **value) { struct security_hook_list *hp; + char *final = NULL; + char *cp; + int rc = 0; + int finallen = 0; int display = lsm_task_display(current); int slot = 0; @@ -2126,6 +2130,29 @@ int security_getprocattr(struct task_struct *p, const char *lsm, char *name, return -ENOMEM; } + if (!strcmp(name, "context")) { + hlist_for_each_entry(hp, &security_hook_heads.getprocattr, + list) { + rc = hp->hook.getprocattr(p, "current", &cp); + if (rc == -EINVAL || rc == -ENOPROTOOPT) + continue; + if (rc < 0) { + kfree(final); + return rc; + } + rc = append_ctx(&final, &finallen, hp->lsmid->lsm, + cp, rc); + if (rc < 0) { + kfree(final); + return rc; + } + } + if (final == NULL) + return -EINVAL; + *value = final; + return finallen; + } + hlist_for_each_entry(hp, &security_hook_heads.getprocattr, list) { if (lsm != NULL && strcmp(lsm, hp->lsmid->lsm)) continue;
Add an entry /proc/.../attr/context which displays the full process security "context" in compound format:' lsm1\0value\0lsm2\0value\0... This entry is not writable. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> cc: linux-api@vger.kernel.org --- fs/proc/base.c | 1 + security/security.c | 27 +++++++++++++++++++++++++++ 2 files changed, 28 insertions(+)