diff mbox series

[v7,02/16] elf: Add _dl_audit_activity_map and _dl_audit_activity_nsid

Message ID 20211222132712.523295-3-adhemerval.zanella@linaro.org
State Committed
Headers
Series Multiple rtld-audit fixes |

Checks

Context Check Description
dj/TryBot-apply_patch success Patch applied to master at the time it was sent

Commit Message

Adhemerval Zanella Netto Dec. 22, 2021, 1:26 p.m. UTC 
  It consolidates the code required to call la_activity audit
callback.

Also for a new Lmid_t the namespace link_map list are empty, so it
requires to check if before using it.  This can happen for when audit
module is used along with dlmopen.

Checked on x86_64-linux-gnu, i686-linux-gnu, and aarch64-linux-gnu.
---
 elf/dl-audit.c             | 30 ++++++++++++++++++++++++
 elf/dl-close.c             | 47 ++------------------------------------
 elf/dl-load.c              | 20 ++--------------
 elf/dl-open.c              | 20 +---------------
 elf/rtld.c                 | 31 ++-----------------------
 sysdeps/generic/ldsodefs.h | 10 ++++++++
 6 files changed, 47 insertions(+), 111 deletions(-)

Comments

Florian Weimer Dec. 24, 2021, 11:58 a.m. UTC | #1 
* Adhemerval Zanella:

> diff --git a/elf/dl-audit.c b/elf/dl-audit.c
> index 4066dfe851..b44ecde135 100644
> --- a/elf/dl-audit.c
> +++ b/elf/dl-audit.c
> @@ -18,6 +18,36 @@

> +void
> +_dl_audit_activity_nsid (Lmid_t nsid, int action)
> +{
> +  /* Auditing checkpoint: we have deleted all objects.  If head is NULL, the
> +     namespace has become empty, and the audit interface does not give us a
> +     way to signal LA_ACT_CONSISTENT for it because the first loaded module
> +     is used to identify the namespace.
> +
> +     Furthermore, do not notify auditors of the cleanup of a failed audit
> +     module loading attempt.  */
> +  struct link_map *head = GL(dl_ns)[nsid]._ns_loaded;
> +  if (__glibc_likely (GLRO(dl_naudit) == 0)
> +      || head == NULL || head->l_auditing)
> +    return;
> +
> +  _dl_audit_activity_map (head, action);
> +}

I think it's probably best to split this comment and keep the “Auditing
checkpoint: we have deleted all objects.” in elf/dl-close.c.  Likewise
the failed loading attempt (although I don't quite see how this
applies).

> +/* Call the la_activity() from the audit modules from the link map L
> +   and issues the ACTION argument.  */
> +void _dl_audit_activity_map (struct link_map *l, int action)
> +  attribute_hidden;
> +
> +/* Call the la_activity() from the audit modules from the link map
> +   from the namespace NSID and issues the ACTION argument.  */
> +void _dl_audit_activity_nsid (Lmid_t nsid, int action)
> +  attribute_hidden;

() is still there …

Rest looks okay.

Reviewed-by: Florian Weimer <fweimer@redhat.com>

Thanks,
Florian
Adhemerval Zanella Netto Dec. 27, 2021, 12:10 p.m. UTC | #2 
On 24/12/2021 08:58, Florian Weimer wrote:
> * Adhemerval Zanella:
> 
>> diff --git a/elf/dl-audit.c b/elf/dl-audit.c
>> index 4066dfe851..b44ecde135 100644
>> --- a/elf/dl-audit.c
>> +++ b/elf/dl-audit.c
>> @@ -18,6 +18,36 @@
> 
>> +void
>> +_dl_audit_activity_nsid (Lmid_t nsid, int action)
>> +{
>> +  /* Auditing checkpoint: we have deleted all objects.  If head is NULL, the
>> +     namespace has become empty, and the audit interface does not give us a
>> +     way to signal LA_ACT_CONSISTENT for it because the first loaded module
>> +     is used to identify the namespace.
>> +
>> +     Furthermore, do not notify auditors of the cleanup of a failed audit
>> +     module loading attempt.  */
>> +  struct link_map *head = GL(dl_ns)[nsid]._ns_loaded;
>> +  if (__glibc_likely (GLRO(dl_naudit) == 0)
>> +      || head == NULL || head->l_auditing)
>> +    return;
>> +
>> +  _dl_audit_activity_map (head, action);
>> +}
> 
> I think it's probably best to split this comment and keep the “Auditing
> checkpoint: we have deleted all objects.” in elf/dl-close.c.  Likewise
> the failed loading attempt (although I don't quite see how this
> applies).

Ack, I will move it back to dl-close.c.

> 
>> +/* Call the la_activity() from the audit modules from the link map L
>> +   and issues the ACTION argument.  */
>> +void _dl_audit_activity_map (struct link_map *l, int action)
>> +  attribute_hidden;
>> +
>> +/* Call the la_activity() from the audit modules from the link map
>> +   from the namespace NSID and issues the ACTION argument.  */
>> +void _dl_audit_activity_nsid (Lmid_t nsid, int action)
>> +  attribute_hidden;
> 
> () is still there …

Ack, I will remove them.

> 
> Rest looks okay.
> 
> Reviewed-by: Florian Weimer <fweimer@redhat.com>
> 
> Thanks,
> Florian
>
diff mbox series

Patch

diff --git a/elf/dl-audit.c b/elf/dl-audit.c
index 4066dfe851..b44ecde135 100644
--- a/elf/dl-audit.c
+++ b/elf/dl-audit.c
@@ -18,6 +18,36 @@ 
 
 #include <ldsodefs.h>
 
+void
+_dl_audit_activity_map (struct link_map *l, int action)
+{
+  struct audit_ifaces *afct = GLRO(dl_audit);
+  for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
+    {
+      if (afct->activity != NULL)
+	afct->activity (&link_map_audit_state (l, cnt)->cookie, action);
+      afct = afct->next;
+    }
+}
+
+void
+_dl_audit_activity_nsid (Lmid_t nsid, int action)
+{
+  /* Auditing checkpoint: we have deleted all objects.  If head is NULL, the
+     namespace has become empty, and the audit interface does not give us a
+     way to signal LA_ACT_CONSISTENT for it because the first loaded module
+     is used to identify the namespace.
+
+     Furthermore, do not notify auditors of the cleanup of a failed audit
+     module loading attempt.  */
+  struct link_map *head = GL(dl_ns)[nsid]._ns_loaded;
+  if (__glibc_likely (GLRO(dl_naudit) == 0)
+      || head == NULL || head->l_auditing)
+    return;
+
+  _dl_audit_activity_map (head, action);
+}
+
 void
 _dl_audit_objopen (struct link_map *l, Lmid_t nsid)
 {
diff --git a/elf/dl-close.c b/elf/dl-close.c
index 4f5cfcc1c3..b9a610981f 100644
--- a/elf/dl-close.c
+++ b/elf/dl-close.c
@@ -472,25 +472,7 @@  _dl_close_worker (struct link_map *map, bool force)
 
 #ifdef SHARED
   /* Auditing checkpoint: we will start deleting objects.  */
-  if (__glibc_unlikely (do_audit))
-    {
-      struct link_map *head = ns->_ns_loaded;
-      struct audit_ifaces *afct = GLRO(dl_audit);
-      /* Do not call the functions for any auditing object.  */
-      if (head->l_auditing == 0)
-	{
-	  for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
-	    {
-	      if (afct->activity != NULL)
-		{
-		  struct auditstate *state = link_map_audit_state (head, cnt);
-		  afct->activity (&state->cookie, LA_ACT_DELETE);
-		}
-
-	      afct = afct->next;
-	    }
-	}
-    }
+  _dl_audit_activity_nsid (nsid, LA_ACT_DELETE);
 #endif
 
   /* Notify the debugger we are about to remove some loaded objects.  */
@@ -785,32 +767,7 @@  _dl_close_worker (struct link_map *map, bool force)
   __rtld_lock_unlock_recursive (GL(dl_load_tls_lock));
 
 #ifdef SHARED
-  /* Auditing checkpoint: we have deleted all objects.  */
-  if (__glibc_unlikely (do_audit))
-    {
-      struct link_map *head = ns->_ns_loaded;
-      /* If head is NULL, the namespace has become empty, and the
-	 audit interface does not give us a way to signal
-	 LA_ACT_CONSISTENT for it because the first loaded module is
-	 used to identify the namespace.
-
-	 Furthermore, do not notify auditors of the cleanup of a
-	 failed audit module loading attempt.  */
-      if (head != NULL && head->l_auditing == 0)
-	{
-	  struct audit_ifaces *afct = GLRO(dl_audit);
-	  for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
-	    {
-	      if (afct->activity != NULL)
-		{
-		  struct auditstate *state = link_map_audit_state (head, cnt);
-		  afct->activity (&state->cookie, LA_ACT_CONSISTENT);
-		}
-
-	      afct = afct->next;
-	    }
-	}
-    }
+  _dl_audit_activity_nsid (nsid, LA_ACT_CONSISTENT);
 #endif
 
   if (__builtin_expect (ns->_ns_loaded == NULL, 0)
diff --git a/elf/dl-load.c b/elf/dl-load.c
index 57de24491a..d1d02fa70e 100644
--- a/elf/dl-load.c
+++ b/elf/dl-load.c
@@ -1488,24 +1488,8 @@  cannot enable executable stack as shared object requires");
       /* Auditing checkpoint: we are going to add new objects.  Since this
          is called after _dl_add_to_namespace_list the namespace is guaranteed
 	 to not be empty.  */
-      if ((mode & __RTLD_AUDIT) == 0
-	  && __glibc_unlikely (GLRO(dl_naudit) > 0))
-	{
-	  struct link_map *head = GL(dl_ns)[nsid]._ns_loaded;
-	  /* Do not call the functions for any auditing object.  */
-	  if (head->l_auditing == 0)
-	    {
-	      struct audit_ifaces *afct = GLRO(dl_audit);
-	      for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
-		{
-		  if (afct->activity != NULL)
-		    afct->activity (&link_map_audit_state (head, cnt)->cookie,
-				    LA_ACT_ADD);
-
-		  afct = afct->next;
-		}
-	    }
-	}
+      if ((mode & __RTLD_AUDIT) == 0)
+	_dl_audit_activity_nsid (nsid, LA_ACT_ADD);
 #endif
 
       /* Notify the debugger we have added some objects.  We need to
diff --git a/elf/dl-open.c b/elf/dl-open.c
index 6ea5dd2457..e2f2e713e7 100644
--- a/elf/dl-open.c
+++ b/elf/dl-open.c
@@ -611,25 +611,7 @@  dl_open_worker_begin (void *a)
 
 #ifdef SHARED
   /* Auditing checkpoint: we have added all objects.  */
-  if (__glibc_unlikely (GLRO(dl_naudit) > 0))
-    {
-      struct link_map *head = GL(dl_ns)[new->l_ns]._ns_loaded;
-      /* Do not call the functions for any auditing object.  */
-      if (head->l_auditing == 0)
-	{
-	  struct audit_ifaces *afct = GLRO(dl_audit);
-	  for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
-	    {
-	      if (afct->activity != NULL)
-		{
-		  struct auditstate *state = link_map_audit_state (head, cnt);
-		  afct->activity (&state->cookie, LA_ACT_CONSISTENT);
-		}
-
-	      afct = afct->next;
-	    }
-	}
-    }
+  _dl_audit_activity_nsid (new->l_ns, LA_ACT_CONSISTENT);
 #endif
 
   /* Notify the debugger all new objects are now ready to go.  */
diff --git a/elf/rtld.c b/elf/rtld.c
index 6b8316e8a9..4952170621 100644
--- a/elf/rtld.c
+++ b/elf/rtld.c
@@ -1794,18 +1794,7 @@  dl_main (const ElfW(Phdr) *phdr,
 
   /* Auditing checkpoint: we are ready to signal that the initial map
      is being constructed.  */
-  if (__glibc_unlikely (GLRO(dl_naudit) > 0))
-    {
-      struct audit_ifaces *afct = GLRO(dl_audit);
-      for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
-	{
-	  if (afct->activity != NULL)
-	    afct->activity (&link_map_audit_state (main_map, cnt)->cookie,
-			    LA_ACT_ADD);
-
-	  afct = afct->next;
-	}
-    }
+  _dl_audit_activity_map (main_map, LA_ACT_ADD);
 
   /* We have two ways to specify objects to preload: via environment
      variable and via the file /etc/ld.so.preload.  The latter can also
@@ -2486,23 +2475,7 @@  dl_main (const ElfW(Phdr) *phdr,
 
 #ifdef SHARED
   /* Auditing checkpoint: we have added all objects.  */
-  if (__glibc_unlikely (GLRO(dl_naudit) > 0))
-    {
-      struct link_map *head = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
-      /* Do not call the functions for any auditing object.  */
-      if (head->l_auditing == 0)
-	{
-	  struct audit_ifaces *afct = GLRO(dl_audit);
-	  for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
-	    {
-	      if (afct->activity != NULL)
-		afct->activity (&link_map_audit_state (head, cnt)->cookie,
-				LA_ACT_CONSISTENT);
-
-	      afct = afct->next;
-	    }
-	}
-    }
+  _dl_audit_activity_nsid (LM_ID_BASE, LA_ACT_CONSISTENT);
 #endif
 
   /* Notify the debugger all new objects are now ready to go.  We must re-get
diff --git a/sysdeps/generic/ldsodefs.h b/sysdeps/generic/ldsodefs.h
index c38a89f3d0..e54efe65c8 100644
--- a/sysdeps/generic/ldsodefs.h
+++ b/sysdeps/generic/ldsodefs.h
@@ -1396,6 +1396,16 @@  link_map_audit_state (struct link_map *l, size_t index)
     }
 }
 
+/* Call the la_activity() from the audit modules from the link map L
+   and issues the ACTION argument.  */
+void _dl_audit_activity_map (struct link_map *l, int action)
+  attribute_hidden;
+
+/* Call the la_activity() from the audit modules from the link map
+   from the namespace NSID and issues the ACTION argument.  */
+void _dl_audit_activity_nsid (Lmid_t nsid, int action)
+  attribute_hidden;
+
 /* Call the la_objopen from the audit modules for the link_map L on the
    namespace identification NSID.  */
 void _dl_audit_objopen (struct link_map *l, Lmid_t nsid)