From 4fd8da8d62416d0dae05603ab5990a498d9aeb12 Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Wed, 23 Sep 2009 17:49:55 +0200 Subject: [PATCH] fs: change sys_truncate length parameter type For this system call user space passes a signed long length parameter, while the kernel side takes an unsigned long parameter and converts it later to signed long again. This has led to bugs in compat wrappers see e.g. dd90bbd5 "powerpc: Add compat_sys_truncate". The s390 compat wrapper for this functions is broken as well since it also performs zero extension instead of sign extension for the length parameter. In addition if hpa comes up with an automated way of generating compat wrappers it would generate a wrong one here. So change the length parameter from unsigned long to long. Cc: "H. Peter Anvin" Cc: Al Viro Cc: Christoph Hellwig Signed-off-by: Heiko Carstens Signed-off-by: Linus Torvalds --- fs/open.c | 5 ++--- include/linux/syscalls.h | 3 +-- 2 files changed, 3 insertions(+), 5 deletions(-) diff --git a/fs/open.c b/fs/open.c index 31191bf..4f01e06 100644 --- a/fs/open.c +++ b/fs/open.c @@ -290,10 +290,9 @@ out: return error; } -SYSCALL_DEFINE2(truncate, const char __user *, path, unsigned long, length) +SYSCALL_DEFINE2(truncate, const char __user *, path, long, length) { - /* on 32-bit boxen it will cut the range 2^31--2^32-1 off */ - return do_sys_truncate(path, (long)length); + return do_sys_truncate(path, length); } static long do_sys_ftruncate(unsigned int fd, loff_t length, int small) diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index 8d8285a1..a990ace 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -460,8 +460,7 @@ asmlinkage long sys_mount(char __user *dev_name, char __user *dir_name, void __user *data); asmlinkage long sys_umount(char __user *name, int flags); asmlinkage long sys_oldumount(char __user *name); -asmlinkage long sys_truncate(const char __user *path, - unsigned long length); +asmlinkage long sys_truncate(const char __user *path, long length); asmlinkage long sys_ftruncate(unsigned int fd, unsigned long length); asmlinkage long sys_stat(char __user *filename, struct __old_kernel_stat __user *statbuf); -- 2.7.4