[binutils-gdb] Fix read after xfree in linux-nat.c:linux_nat_detach

[Pedro Alves <palves at sourceware dot org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=a6acac06113f4b04fa0333ee2a3ab3025b43ee7c

commit a6acac06113f4b04fa0333ee2a3ab3025b43ee7c
Author: Philipp Rudo <prudo@linux.vnet.ibm.com>
Date:   Tue Apr 11 14:28:51 2017 +0100

    Fix read after xfree in linux-nat.c:linux_nat_detach
    
    At the end of linux_nat_detach the main_lwp is deleted (delete_lwp).
    This is problematic as during detach (detach_one_lwp and
    linux_fork_detach) main_lwp already gets freed.  Thus calling
    delete_lwp causes a read after free.  Fix it by removing the
    unnecessary delete_lwp.
    
    gdb/ChangeLog:
    2017-04-11  Philipp Rudo  <prudo@linux.vnet.ibm.com>
    
    	* linux-nat.c (linux_nat_detach): Remove delete_lwp call.

Diff:
---
 gdb/ChangeLog   | 4 ++++
 gdb/linux-nat.c | 1 -
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index dc3393a..60e03e7 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,7 @@
+2017-04-11  Philipp Rudo  <prudo@linux.vnet.ibm.com>
+
+	* linux-nat.c (linux_nat_detach): Remove delete_lwp call.
+
 2017-04-11  Alan Hayward  <alan.hayward@arm.com>
 
 	* arm-tdep.c (arm_store_return_value): Use FP_REGISTER_SIZE
diff --git a/gdb/linux-nat.c b/gdb/linux-nat.c
index b06e400..8dececf 100644
--- a/gdb/linux-nat.c
+++ b/gdb/linux-nat.c
@@ -1549,7 +1549,6 @@ linux_nat_detach (struct target_ops *ops, const char *args, int from_tty)
 
       inf_ptrace_detach_success (ops);
     }
-  delete_lwp (main_lwp->ptid);
 }
 
 /* Resume execution of the inferior process.  If STEP is nonzero,