[PATCH] exec: don't turn PF_KTHREAD off when command not found

From: KOSAKI Motohiro
Date: Thu Sep 09 2010 - 05:03:43 EST


Now, do_execve() turn PF_KTHREAD off before search_binary_handler().
It has theorical risk of PF_KTHREAD lost. When ENOEXEC case, we don't
have to turn PF_KTHREAD off.

This patch move this flag modification after founding execution file.

I guess this is only theorical issue because now any kthread don't
call do_execve() directly. but anyway fixing would be better.

Cc: Roland McGrath <roland@xxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
---
fs/exec.c | 3 +--
1 files changed, 1 insertions(+), 2 deletions(-)

diff --git a/fs/exec.c b/fs/exec.c
index ef8b9dc..81d0d06 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1011,7 +1011,7 @@ int flush_old_exec(struct linux_binprm * bprm)
bprm->mm = NULL; /* We're using it now */
set_exec_mm(NULL);

- current->flags &= ~PF_RANDOMIZE;
+ current->flags &= ~(PF_RANDOMIZE | PF_KTHREAD);
flush_thread();
current->personality &= ~bprm->per_clear;

@@ -1421,7 +1421,6 @@ int do_execve(const char * filename,
if (retval < 0)
goto out;

- current->flags &= ~PF_KTHREAD;
retval = search_binary_handler(bprm,regs);
if (retval < 0)
goto out;
--
1.6.5.2



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