From 3b9b8ab65d8eed784b9164d03807cb2bda7b5cd6 Mon Sep 17 00:00:00 2001 From: Kirill Korotaev Date: Fri, 29 Sep 2006 02:00:05 -0700 Subject: [PATCH] Fix unserialized task->files changing Fixed race on put_files_struct on exec with proc. Restoring files on current on error path may lead to proc having a pointer to already kfree-d files_struct. ->files changing at exit.c and khtread.c are safe as exit_files() makes all things under lock. Found during OpenVZ stress testing. [akpm@osdl.org: add export] Signed-off-by: Pavel Emelianov Signed-off-by: Kirill Korotaev Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/exit.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'kernel') diff --git a/kernel/exit.c b/kernel/exit.c index d891883420f7..4b6fb054b25d 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -487,6 +487,18 @@ void fastcall put_files_struct(struct files_struct *files) EXPORT_SYMBOL(put_files_struct); +void reset_files_struct(struct task_struct *tsk, struct files_struct *files) +{ + struct files_struct *old; + + old = tsk->files; + task_lock(tsk); + tsk->files = files; + task_unlock(tsk); + put_files_struct(old); +} +EXPORT_SYMBOL(reset_files_struct); + static inline void __exit_files(struct task_struct *tsk) { struct files_struct * files = tsk->files; -- cgit v1.2.3