Re: [PATCH] Return EPERM not ECHILD on security_task_wait failure
On Mon, 23 Apr 2007, Roland McGrath wrote: > As I said in some earlier discussion following my original patch, that > would be fine with me. I haven't coded up that variant, but it's simple > enough. Would you like to do it? Sure. -- James Morris <[EMAIL PROTECTED]> - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] Return EPERM not ECHILD on security_task_wait failure
> On Thu, 15 Mar 2007, Roland McGrath wrote: > > > This patch makes do_wait return -EPERM instead of -ECHILD if some > > children were ruled out solely because security_task_wait failed. > > What about using the return value from the security_task_wait hook (which > should be -EACCES) ? As I said in some earlier discussion following my original patch, that would be fine with me. I haven't coded up that variant, but it's simple enough. Would you like to do it? Thanks, Roland - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] Return EPERM not ECHILD on security_task_wait failure
On Thu, 15 Mar 2007, Roland McGrath wrote: > This patch makes do_wait return -EPERM instead of -ECHILD if some > children were ruled out solely because security_task_wait failed. What about using the return value from the security_task_wait hook (which should be -EACCES) ? - James -- James Morris <[EMAIL PROTECTED]> - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] Return EPERM not ECHILD on security_task_wait failure
On Thu, 15 Mar 2007, Roland McGrath wrote: This patch makes do_wait return -EPERM instead of -ECHILD if some children were ruled out solely because security_task_wait failed. What about using the return value from the security_task_wait hook (which should be -EACCES) ? - James -- James Morris [EMAIL PROTECTED] - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] Return EPERM not ECHILD on security_task_wait failure
On Thu, 15 Mar 2007, Roland McGrath wrote: This patch makes do_wait return -EPERM instead of -ECHILD if some children were ruled out solely because security_task_wait failed. What about using the return value from the security_task_wait hook (which should be -EACCES) ? As I said in some earlier discussion following my original patch, that would be fine with me. I haven't coded up that variant, but it's simple enough. Would you like to do it? Thanks, Roland - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] Return EPERM not ECHILD on security_task_wait failure
On Mon, 23 Apr 2007, Roland McGrath wrote: As I said in some earlier discussion following my original patch, that would be fine with me. I haven't coded up that variant, but it's simple enough. Would you like to do it? Sure. -- James Morris [EMAIL PROTECTED] - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH] Return EPERM not ECHILD on security_task_wait failure
wait* syscalls return -ECHILD even when an individual PID of a live
child was requested explicitly, when security_task_wait denies the
operation. This means that something like a broken SELinux policy
can produce an unexpected failure that looks just like a bug with
wait or ptrace or something.
This patch makes do_wait return -EPERM instead of -ECHILD if some
children were ruled out solely because security_task_wait failed.
Signed-off-by: Roland McGrath <[EMAIL PROTECTED]>
---
kernel/exit.c | 12 +++-
1 files changed, 11 insertions(+), 1 deletions(-)
diff --git a/kernel/exit.c b/kernel/exit.c
index f132349..a41052f 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -1067,7 +1067,7 @@ static int eligible_child(pid_t pid, int
return 2;
if (security_task_wait(p))
- return 0;
+ return -1;
return 1;
}
@@ -1449,6 +1449,7 @@ static long do_wait(pid_t pid, int optio
DECLARE_WAITQUEUE(wait, current);
struct task_struct *tsk;
int flag, retval;
+ int allowed, denied;
add_wait_queue(>signal->wait_chldexit,);
repeat:
@@ -1457,6 +1458,7 @@ repeat:
* match our criteria, even if we are not able to reap it yet.
*/
flag = 0;
+ allowed = denied = 0;
current->state = TASK_INTERRUPTIBLE;
read_lock(_lock);
tsk = current;
@@ -1472,6 +1474,12 @@ repeat:
if (!ret)
continue;
+ if (unlikely(ret < 0)) {
+ denied = 1;
+ continue;
+ }
+ allowed = 1;
+
switch (p->state) {
case TASK_TRACED:
/*
@@ -1570,6 +1578,8 @@ check_continued:
goto repeat;
}
retval = -ECHILD;
+ if (unlikely(denied) && !allowed)
+ retval = -EPERM;
end:
current->state = TASK_RUNNING;
remove_wait_queue(>signal->wait_chldexit,);
-
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Please read the FAQ at http://www.tux.org/lkml/
[PATCH] Return EPERM not ECHILD on security_task_wait failure
wait* syscalls return -ECHILD even when an individual PID of a live
child was requested explicitly, when security_task_wait denies the
operation. This means that something like a broken SELinux policy
can produce an unexpected failure that looks just like a bug with
wait or ptrace or something.
This patch makes do_wait return -EPERM instead of -ECHILD if some
children were ruled out solely because security_task_wait failed.
Signed-off-by: Roland McGrath [EMAIL PROTECTED]
---
kernel/exit.c | 12 +++-
1 files changed, 11 insertions(+), 1 deletions(-)
diff --git a/kernel/exit.c b/kernel/exit.c
index f132349..a41052f 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -1067,7 +1067,7 @@ static int eligible_child(pid_t pid, int
return 2;
if (security_task_wait(p))
- return 0;
+ return -1;
return 1;
}
@@ -1449,6 +1449,7 @@ static long do_wait(pid_t pid, int optio
DECLARE_WAITQUEUE(wait, current);
struct task_struct *tsk;
int flag, retval;
+ int allowed, denied;
add_wait_queue(current-signal-wait_chldexit,wait);
repeat:
@@ -1457,6 +1458,7 @@ repeat:
* match our criteria, even if we are not able to reap it yet.
*/
flag = 0;
+ allowed = denied = 0;
current-state = TASK_INTERRUPTIBLE;
read_lock(tasklist_lock);
tsk = current;
@@ -1472,6 +1474,12 @@ repeat:
if (!ret)
continue;
+ if (unlikely(ret 0)) {
+ denied = 1;
+ continue;
+ }
+ allowed = 1;
+
switch (p-state) {
case TASK_TRACED:
/*
@@ -1570,6 +1578,8 @@ check_continued:
goto repeat;
}
retval = -ECHILD;
+ if (unlikely(denied) !allowed)
+ retval = -EPERM;
end:
current-state = TASK_RUNNING;
remove_wait_queue(current-signal-wait_chldexit,wait);
-
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