Re: 2.6.7 Oops in signal handling with ptrace

[Andrew Morton]

Joris van Rantwijk <joris@xxxxxxxxxx> wrote:
>
> Linux 2.6.7 (and 2.6.6) gives an Oops in specific situations
>  related to signal handling and ptracing. The Oops is triggered when
>  a process which is being ptraced with TRACESYSGOOD, receives signals
>  in a very specific pattern. This Oops is perfectly reproducable.

Joris, Linus has merged a patch similar to yours which should address this
problem.  Many thanks for tracking this down.



From: Linux Kernel Mailing List <linux-kernel@xxxxxxxxxxxxxxx>
To: bk-commits-head@xxxxxxxxxxxxxxx
Subject: Follow 2.4.x semantics for in-kernel signal sending.
Date: Sun, 20 Jun 2004 16:56:58 +0000
Sender: bk-commits-head-owner@xxxxxxxxxxxxxxx

 ChangeSet 1.1769, 2004/06/20 09:56:58-07:00, torvalds@xxxxxxxxxxxxxxx

 	Follow 2.4.x semantics for in-kernel signal sending.



  signal.c |    7 +++++++
  1 files changed, 7 insertions(+)


 diff -Nru a/kernel/signal.c b/kernel/signal.c
 --- a/kernel/signal.c	2004-06-20 11:07:49 -07:00
 +++ b/kernel/signal.c	2004-06-20 11:07:49 -07:00
 @@ -1197,6 +1197,13 @@
  	unsigned long flags;
  
  	/*
 +	 * Make sure legacy kernel users don't send in bad values
 +	 * (normal paths check this in check_kill_permission).
 +	 */
 +	if (sig < 0 || sig > _NSIG)
 +		return -EINVAL;
 +
 +	/*
  	 * We need the tasklist lock even for the specific
  	 * thread case (when we don't need to follow the group
  	 * lists) in order to avoid races with "p->sighand"
 -
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