Re: [PATCH] audit: process errors from filter user rules

2013-12-09 Thread Richard Guy Briggs
On 13/12/05, Eric Paris wrote:
> I know we talked about this patch, and it seemed like a good idea at the
> time, but honestly, these races are so rare, it isn't worth the code
> complexity.  I tried to simplify the readability of your code and got
> something better, but still the loop is needless...

Your original code suggestion was cleaner and simpler than mine, but I
tried to code it in a structured manner without gotos, perhaps naively
believing structured code to be superior.  I think that effort backfired
and made it more complex.  I'm ok going back to your original ideas.

I do still think that retry and passing back of error codes is the
better approach.

> Just log the messages on any error, even with a dontaudit rule...   How
> about a function like:

I suspect this isn't what you intended.  The way this is written, it
always breaks after the first rule, not checking any of the others.

> int audit_filter_user(int type)
> {
> enum audit_state state = AUDIT_DISABLED;
> struct audit_entry *e;
> int rc, ret;
> 
> ret = 1; /* Audit by default */
> 
> rcu_read_lock();
> list_for_each_entry_rcu(e, _filter_list[AUDIT_FILTER_USER], 
> list) {
> rc = audit_filter_user_rules(>rule, type, );
> if (rc > 0 && state == AUDIT_DISABLED)
> ret = 0;
> break;
> }
> rcu_read_unlock();
> return ret;
> }

Did you mean?

list_for_each_entry_rcu(e, _filter_list[AUDIT_FILTER_USER], list) 
{
rc = audit_filter_user_rules(>rule, type, );
if (rc) {
if (rc > 0 && state == AUDIT_DISABLED)
ret = 0;
break;
}
}

> and use some sense with the 80 character line length rule.  It's 81
> long.  Just let it be long even if checkpatch whines

Yeah, I haven't been too pedantic about line length warnings barely over
80 characters when it affects readability...

> -Eric
> 
> On Wed, 2013-12-04 at 22:45 -0500, Richard Guy Briggs wrote:
> > Errors from filter user rules were previously ignored, and worse, an error 
> > on
> > a AUDIT_NEVER rule disabled logging on that rule.  On -ESTALE, retry up to 5
> > times.  On error on AUDIT_NEVER rules, log.
> > 
> > Signed-off-by: Richard Guy Briggs 
> > ---
> >  kernel/audit.c   |2 +-
> >  kernel/auditfilter.c |   44 +++-
> >  2 files changed, 32 insertions(+), 14 deletions(-)
> > 
> > diff --git a/kernel/audit.c b/kernel/audit.c
> > index 4cbc945..c93cf06 100644
> > --- a/kernel/audit.c
> > +++ b/kernel/audit.c
> > @@ -706,7 +706,7 @@ static int audit_receive_msg(struct sk_buff *skb, 
> > struct nlmsghdr *nlh)
> > return 0;
> >  
> > err = audit_filter_user(msg_type);
> > -   if (err == 1) {
> > +   if (err) { /* match or error */
> > err = 0;
> > if (msg_type == AUDIT_USER_TTY) {
> > err = tty_audit_push_current();
> > diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
> > index b4c6e03..1a7dfa5 100644
> > --- a/kernel/auditfilter.c
> > +++ b/kernel/auditfilter.c
> > @@ -1272,8 +1272,8 @@ static int audit_filter_user_rules(struct audit_krule 
> > *rule, int type,
> > break;
> > }
> >  
> > -   if (!result)
> > -   return 0;
> > +   if (result <= 0)
> > +   return result;
> > }
> > switch (rule->action) {
> > case AUDIT_NEVER:*state = AUDIT_DISABLED;   break;
> > @@ -1286,19 +1286,37 @@ int audit_filter_user(int type)
> >  {
> > enum audit_state state = AUDIT_DISABLED;
> > struct audit_entry *e;
> > -   int ret = 1;
> > -
> > -   rcu_read_lock();
> > -   list_for_each_entry_rcu(e, _filter_list[AUDIT_FILTER_USER], list) 
> > {
> > -   if (audit_filter_user_rules(>rule, type, )) {
> > -   if (state == AUDIT_DISABLED)
> > -   ret = 0;
> > -   break;
> > +   int rc, count = 0, retry = 0, ret = 1; /* Audit by default */
> > +#define FILTER_RETRY_LIMIT 5
> > +
> > +   do {
> > +   rcu_read_lock();
> > +   list_for_each_entry_rcu(e,
> > +   _filter_list[AUDIT_FILTER_USER],
> > +   list) {
> > +   retry = 0;
> > +   rc = audit_filter_user_rules(>rule, type, );
> > +   if (rc > 0) {
> > +   if (state == AUDIT_DISABLED)
> > +   ret = 0;
> > +   break;
> > +   } else if (rc < 0) {
> > +   if (rc == -ESTALE && count < 
> > FILTER_RETRY_LIMIT) {
> > +   rcu_read_unlock();
> > +   

Re: [PATCH] audit: process errors from filter user rules

2013-12-09 Thread Richard Guy Briggs
On 13/12/05, Eric Paris wrote:
 I know we talked about this patch, and it seemed like a good idea at the
 time, but honestly, these races are so rare, it isn't worth the code
 complexity.  I tried to simplify the readability of your code and got
 something better, but still the loop is needless...

Your original code suggestion was cleaner and simpler than mine, but I
tried to code it in a structured manner without gotos, perhaps naively
believing structured code to be superior.  I think that effort backfired
and made it more complex.  I'm ok going back to your original ideas.

I do still think that retry and passing back of error codes is the
better approach.

 Just log the messages on any error, even with a dontaudit rule...   How
 about a function like:

I suspect this isn't what you intended.  The way this is written, it
always breaks after the first rule, not checking any of the others.

 int audit_filter_user(int type)
 {
 enum audit_state state = AUDIT_DISABLED;
 struct audit_entry *e;
 int rc, ret;
 
 ret = 1; /* Audit by default */
 
 rcu_read_lock();
 list_for_each_entry_rcu(e, audit_filter_list[AUDIT_FILTER_USER], 
 list) {
 rc = audit_filter_user_rules(e-rule, type, state);
 if (rc  0  state == AUDIT_DISABLED)
 ret = 0;
 break;
 }
 rcu_read_unlock();
 return ret;
 }

Did you mean?

list_for_each_entry_rcu(e, audit_filter_list[AUDIT_FILTER_USER], list) 
{
rc = audit_filter_user_rules(e-rule, type, state);
if (rc) {
if (rc  0  state == AUDIT_DISABLED)
ret = 0;
break;
}
}

 and use some sense with the 80 character line length rule.  It's 81
 long.  Just let it be long even if checkpatch whines

Yeah, I haven't been too pedantic about line length warnings barely over
80 characters when it affects readability...

 -Eric
 
 On Wed, 2013-12-04 at 22:45 -0500, Richard Guy Briggs wrote:
  Errors from filter user rules were previously ignored, and worse, an error 
  on
  a AUDIT_NEVER rule disabled logging on that rule.  On -ESTALE, retry up to 5
  times.  On error on AUDIT_NEVER rules, log.
  
  Signed-off-by: Richard Guy Briggs r...@redhat.com
  ---
   kernel/audit.c   |2 +-
   kernel/auditfilter.c |   44 +++-
   2 files changed, 32 insertions(+), 14 deletions(-)
  
  diff --git a/kernel/audit.c b/kernel/audit.c
  index 4cbc945..c93cf06 100644
  --- a/kernel/audit.c
  +++ b/kernel/audit.c
  @@ -706,7 +706,7 @@ static int audit_receive_msg(struct sk_buff *skb, 
  struct nlmsghdr *nlh)
  return 0;
   
  err = audit_filter_user(msg_type);
  -   if (err == 1) {
  +   if (err) { /* match or error */
  err = 0;
  if (msg_type == AUDIT_USER_TTY) {
  err = tty_audit_push_current();
  diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
  index b4c6e03..1a7dfa5 100644
  --- a/kernel/auditfilter.c
  +++ b/kernel/auditfilter.c
  @@ -1272,8 +1272,8 @@ static int audit_filter_user_rules(struct audit_krule 
  *rule, int type,
  break;
  }
   
  -   if (!result)
  -   return 0;
  +   if (result = 0)
  +   return result;
  }
  switch (rule-action) {
  case AUDIT_NEVER:*state = AUDIT_DISABLED;   break;
  @@ -1286,19 +1286,37 @@ int audit_filter_user(int type)
   {
  enum audit_state state = AUDIT_DISABLED;
  struct audit_entry *e;
  -   int ret = 1;
  -
  -   rcu_read_lock();
  -   list_for_each_entry_rcu(e, audit_filter_list[AUDIT_FILTER_USER], list) 
  {
  -   if (audit_filter_user_rules(e-rule, type, state)) {
  -   if (state == AUDIT_DISABLED)
  -   ret = 0;
  -   break;
  +   int rc, count = 0, retry = 0, ret = 1; /* Audit by default */
  +#define FILTER_RETRY_LIMIT 5
  +
  +   do {
  +   rcu_read_lock();
  +   list_for_each_entry_rcu(e,
  +   audit_filter_list[AUDIT_FILTER_USER],
  +   list) {
  +   retry = 0;
  +   rc = audit_filter_user_rules(e-rule, type, state);
  +   if (rc  0) {
  +   if (state == AUDIT_DISABLED)
  +   ret = 0;
  +   break;
  +   } else if (rc  0) {
  +   if (rc == -ESTALE  count  
  FILTER_RETRY_LIMIT) {
  +   rcu_read_unlock();
  +   count++;
  +   retry = 1;
  +   cond_resched();
  +

Re: [PATCH] audit: process errors from filter user rules

2013-12-05 Thread Eric Paris
I know we talked about this patch, and it seemed like a good idea at the
time, but honestly, these races are so rare, it isn't worth the code
complexity.  I tried to simplify the readability of your code and got
something better, but still the loop is needless...

Just log the messages on any error, even with a dontaudit rule...   How
about a function like:

int audit_filter_user(int type)
{
enum audit_state state = AUDIT_DISABLED;
struct audit_entry *e;
int rc, ret;

ret = 1; /* Audit by default */

rcu_read_lock();
list_for_each_entry_rcu(e, _filter_list[AUDIT_FILTER_USER], list) 
{
rc = audit_filter_user_rules(>rule, type, );
if (rc > 0 && state == AUDIT_DISABLED)
ret = 0;
break;
}
rcu_read_unlock();
return ret;
}

and use some sense with the 80 character line length rule.  It's 81
long.  Just let it be long even if checkpatch whines

-Eric

On Wed, 2013-12-04 at 22:45 -0500, Richard Guy Briggs wrote:
> Errors from filter user rules were previously ignored, and worse, an error on
> a AUDIT_NEVER rule disabled logging on that rule.  On -ESTALE, retry up to 5
> times.  On error on AUDIT_NEVER rules, log.
> 
> Signed-off-by: Richard Guy Briggs 
> ---
>  kernel/audit.c   |2 +-
>  kernel/auditfilter.c |   44 +++-
>  2 files changed, 32 insertions(+), 14 deletions(-)
> 
> diff --git a/kernel/audit.c b/kernel/audit.c
> index 4cbc945..c93cf06 100644
> --- a/kernel/audit.c
> +++ b/kernel/audit.c
> @@ -706,7 +706,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct 
> nlmsghdr *nlh)
>   return 0;
>  
>   err = audit_filter_user(msg_type);
> - if (err == 1) {
> + if (err) { /* match or error */
>   err = 0;
>   if (msg_type == AUDIT_USER_TTY) {
>   err = tty_audit_push_current();
> diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
> index b4c6e03..1a7dfa5 100644
> --- a/kernel/auditfilter.c
> +++ b/kernel/auditfilter.c
> @@ -1272,8 +1272,8 @@ static int audit_filter_user_rules(struct audit_krule 
> *rule, int type,
>   break;
>   }
>  
> - if (!result)
> - return 0;
> + if (result <= 0)
> + return result;
>   }
>   switch (rule->action) {
>   case AUDIT_NEVER:*state = AUDIT_DISABLED;   break;
> @@ -1286,19 +1286,37 @@ int audit_filter_user(int type)
>  {
>   enum audit_state state = AUDIT_DISABLED;
>   struct audit_entry *e;
> - int ret = 1;
> -
> - rcu_read_lock();
> - list_for_each_entry_rcu(e, _filter_list[AUDIT_FILTER_USER], list) 
> {
> - if (audit_filter_user_rules(>rule, type, )) {
> - if (state == AUDIT_DISABLED)
> - ret = 0;
> - break;
> + int rc, count = 0, retry = 0, ret = 1; /* Audit by default */
> +#define FILTER_RETRY_LIMIT 5
> +
> + do {
> + rcu_read_lock();
> + list_for_each_entry_rcu(e,
> + _filter_list[AUDIT_FILTER_USER],
> + list) {
> + retry = 0;
> + rc = audit_filter_user_rules(>rule, type, );
> + if (rc > 0) {
> + if (state == AUDIT_DISABLED)
> + ret = 0;
> + break;
> + } else if (rc < 0) {
> + if (rc == -ESTALE && count < 
> FILTER_RETRY_LIMIT) {
> + rcu_read_unlock();
> + count++;
> + retry = 1;
> + cond_resched();
> + } else {
> + ret = rc;
> + }
> + break;
> + }
>   }
> - }
> - rcu_read_unlock();
> + if (!retry)
> + rcu_read_unlock();
> + } while (retry);
>  
> - return ret; /* Audit by default */
> + return ret;
>  }
>  
>  int audit_filter_type(int type)


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Re: [PATCH] audit: process errors from filter user rules

2013-12-05 Thread Eric Paris
I know we talked about this patch, and it seemed like a good idea at the
time, but honestly, these races are so rare, it isn't worth the code
complexity.  I tried to simplify the readability of your code and got
something better, but still the loop is needless...

Just log the messages on any error, even with a dontaudit rule...   How
about a function like:

int audit_filter_user(int type)
{
enum audit_state state = AUDIT_DISABLED;
struct audit_entry *e;
int rc, ret;

ret = 1; /* Audit by default */

rcu_read_lock();
list_for_each_entry_rcu(e, audit_filter_list[AUDIT_FILTER_USER], list) 
{
rc = audit_filter_user_rules(e-rule, type, state);
if (rc  0  state == AUDIT_DISABLED)
ret = 0;
break;
}
rcu_read_unlock();
return ret;
}

and use some sense with the 80 character line length rule.  It's 81
long.  Just let it be long even if checkpatch whines

-Eric

On Wed, 2013-12-04 at 22:45 -0500, Richard Guy Briggs wrote:
 Errors from filter user rules were previously ignored, and worse, an error on
 a AUDIT_NEVER rule disabled logging on that rule.  On -ESTALE, retry up to 5
 times.  On error on AUDIT_NEVER rules, log.
 
 Signed-off-by: Richard Guy Briggs r...@redhat.com
 ---
  kernel/audit.c   |2 +-
  kernel/auditfilter.c |   44 +++-
  2 files changed, 32 insertions(+), 14 deletions(-)
 
 diff --git a/kernel/audit.c b/kernel/audit.c
 index 4cbc945..c93cf06 100644
 --- a/kernel/audit.c
 +++ b/kernel/audit.c
 @@ -706,7 +706,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct 
 nlmsghdr *nlh)
   return 0;
  
   err = audit_filter_user(msg_type);
 - if (err == 1) {
 + if (err) { /* match or error */
   err = 0;
   if (msg_type == AUDIT_USER_TTY) {
   err = tty_audit_push_current();
 diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
 index b4c6e03..1a7dfa5 100644
 --- a/kernel/auditfilter.c
 +++ b/kernel/auditfilter.c
 @@ -1272,8 +1272,8 @@ static int audit_filter_user_rules(struct audit_krule 
 *rule, int type,
   break;
   }
  
 - if (!result)
 - return 0;
 + if (result = 0)
 + return result;
   }
   switch (rule-action) {
   case AUDIT_NEVER:*state = AUDIT_DISABLED;   break;
 @@ -1286,19 +1286,37 @@ int audit_filter_user(int type)
  {
   enum audit_state state = AUDIT_DISABLED;
   struct audit_entry *e;
 - int ret = 1;
 -
 - rcu_read_lock();
 - list_for_each_entry_rcu(e, audit_filter_list[AUDIT_FILTER_USER], list) 
 {
 - if (audit_filter_user_rules(e-rule, type, state)) {
 - if (state == AUDIT_DISABLED)
 - ret = 0;
 - break;
 + int rc, count = 0, retry = 0, ret = 1; /* Audit by default */
 +#define FILTER_RETRY_LIMIT 5
 +
 + do {
 + rcu_read_lock();
 + list_for_each_entry_rcu(e,
 + audit_filter_list[AUDIT_FILTER_USER],
 + list) {
 + retry = 0;
 + rc = audit_filter_user_rules(e-rule, type, state);
 + if (rc  0) {
 + if (state == AUDIT_DISABLED)
 + ret = 0;
 + break;
 + } else if (rc  0) {
 + if (rc == -ESTALE  count  
 FILTER_RETRY_LIMIT) {
 + rcu_read_unlock();
 + count++;
 + retry = 1;
 + cond_resched();
 + } else {
 + ret = rc;
 + }
 + break;
 + }
   }
 - }
 - rcu_read_unlock();
 + if (!retry)
 + rcu_read_unlock();
 + } while (retry);
  
 - return ret; /* Audit by default */
 + return ret;
  }
  
  int audit_filter_type(int type)


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Please read the FAQ at  http://www.tux.org/lkml/


[PATCH] audit: process errors from filter user rules

2013-12-04 Thread Richard Guy Briggs
Errors from filter user rules were previously ignored, and worse, an error on
a AUDIT_NEVER rule disabled logging on that rule.  On -ESTALE, retry up to 5
times.  On error on AUDIT_NEVER rules, log.

Signed-off-by: Richard Guy Briggs 
---
 kernel/audit.c   |2 +-
 kernel/auditfilter.c |   44 +++-
 2 files changed, 32 insertions(+), 14 deletions(-)

diff --git a/kernel/audit.c b/kernel/audit.c
index 4cbc945..c93cf06 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -706,7 +706,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct 
nlmsghdr *nlh)
return 0;
 
err = audit_filter_user(msg_type);
-   if (err == 1) {
+   if (err) { /* match or error */
err = 0;
if (msg_type == AUDIT_USER_TTY) {
err = tty_audit_push_current();
diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index b4c6e03..1a7dfa5 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -1272,8 +1272,8 @@ static int audit_filter_user_rules(struct audit_krule 
*rule, int type,
break;
}
 
-   if (!result)
-   return 0;
+   if (result <= 0)
+   return result;
}
switch (rule->action) {
case AUDIT_NEVER:*state = AUDIT_DISABLED;   break;
@@ -1286,19 +1286,37 @@ int audit_filter_user(int type)
 {
enum audit_state state = AUDIT_DISABLED;
struct audit_entry *e;
-   int ret = 1;
-
-   rcu_read_lock();
-   list_for_each_entry_rcu(e, _filter_list[AUDIT_FILTER_USER], list) 
{
-   if (audit_filter_user_rules(>rule, type, )) {
-   if (state == AUDIT_DISABLED)
-   ret = 0;
-   break;
+   int rc, count = 0, retry = 0, ret = 1; /* Audit by default */
+#define FILTER_RETRY_LIMIT 5
+
+   do {
+   rcu_read_lock();
+   list_for_each_entry_rcu(e,
+   _filter_list[AUDIT_FILTER_USER],
+   list) {
+   retry = 0;
+   rc = audit_filter_user_rules(>rule, type, );
+   if (rc > 0) {
+   if (state == AUDIT_DISABLED)
+   ret = 0;
+   break;
+   } else if (rc < 0) {
+   if (rc == -ESTALE && count < 
FILTER_RETRY_LIMIT) {
+   rcu_read_unlock();
+   count++;
+   retry = 1;
+   cond_resched();
+   } else {
+   ret = rc;
+   }
+   break;
+   }
}
-   }
-   rcu_read_unlock();
+   if (!retry)
+   rcu_read_unlock();
+   } while (retry);
 
-   return ret; /* Audit by default */
+   return ret;
 }
 
 int audit_filter_type(int type)
-- 
1.7.1

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Please read the FAQ at  http://www.tux.org/lkml/


[PATCH] audit: process errors from filter user rules

2013-12-04 Thread Richard Guy Briggs
Errors from filter user rules were previously ignored, and worse, an error on
a AUDIT_NEVER rule disabled logging on that rule.  On -ESTALE, retry up to 5
times.  On error on AUDIT_NEVER rules, log.

Signed-off-by: Richard Guy Briggs r...@redhat.com
---
 kernel/audit.c   |2 +-
 kernel/auditfilter.c |   44 +++-
 2 files changed, 32 insertions(+), 14 deletions(-)

diff --git a/kernel/audit.c b/kernel/audit.c
index 4cbc945..c93cf06 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -706,7 +706,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct 
nlmsghdr *nlh)
return 0;
 
err = audit_filter_user(msg_type);
-   if (err == 1) {
+   if (err) { /* match or error */
err = 0;
if (msg_type == AUDIT_USER_TTY) {
err = tty_audit_push_current();
diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index b4c6e03..1a7dfa5 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -1272,8 +1272,8 @@ static int audit_filter_user_rules(struct audit_krule 
*rule, int type,
break;
}
 
-   if (!result)
-   return 0;
+   if (result = 0)
+   return result;
}
switch (rule-action) {
case AUDIT_NEVER:*state = AUDIT_DISABLED;   break;
@@ -1286,19 +1286,37 @@ int audit_filter_user(int type)
 {
enum audit_state state = AUDIT_DISABLED;
struct audit_entry *e;
-   int ret = 1;
-
-   rcu_read_lock();
-   list_for_each_entry_rcu(e, audit_filter_list[AUDIT_FILTER_USER], list) 
{
-   if (audit_filter_user_rules(e-rule, type, state)) {
-   if (state == AUDIT_DISABLED)
-   ret = 0;
-   break;
+   int rc, count = 0, retry = 0, ret = 1; /* Audit by default */
+#define FILTER_RETRY_LIMIT 5
+
+   do {
+   rcu_read_lock();
+   list_for_each_entry_rcu(e,
+   audit_filter_list[AUDIT_FILTER_USER],
+   list) {
+   retry = 0;
+   rc = audit_filter_user_rules(e-rule, type, state);
+   if (rc  0) {
+   if (state == AUDIT_DISABLED)
+   ret = 0;
+   break;
+   } else if (rc  0) {
+   if (rc == -ESTALE  count  
FILTER_RETRY_LIMIT) {
+   rcu_read_unlock();
+   count++;
+   retry = 1;
+   cond_resched();
+   } else {
+   ret = rc;
+   }
+   break;
+   }
}
-   }
-   rcu_read_unlock();
+   if (!retry)
+   rcu_read_unlock();
+   } while (retry);
 
-   return ret; /* Audit by default */
+   return ret;
 }
 
 int audit_filter_type(int type)
-- 
1.7.1

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