From 7f55f13c2ca82f6d998502df70f24deb550e5e0c Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Thu, 11 Nov 2010 11:29:25 -0500 Subject: [PATCH] staging: ft1000: Copy from user into correct data While doing a ktest.pl I used a MIN_CONFIG that had STAGING enabled, and a randconfig with CONFIG_DEBUG_STRICT_USER_COPY_CHECKS enabled caught the following bug: In file included from /home/rostedt/work/autotest/nobackup/linux-test.git/arch/x86/include/asm/uaccess.h:571:0, from /home/rostedt/work/autotest/nobackup/linux-test.git/include/linux/poll.h:14, from /home/rostedt/work/autotest/nobackup/linux-test.git/drivers/staging/ft1000/ft1000-usb/ft1000_chdev.c:32: In function 'copy_from_user', inlined from 'ft1000_ChIoctl' at /home/rostedt/work/autotest/nobackup/linux-test.git/drivers/staging/ft1000/ft1000-usb/ft1000_chdev.c:702:36: /home/rostedt/work/autotest/nobackup/linux-test.git/arch/x86/include/asm/uaccess_32.h:212:26: error: call to 'copy_from_user_overflow' declared with attribute error: copy_from_user() buffer size is not provably correct Looking at the code it was obvious what the problem was. The pointer dpram_data was being allocated but the address was being written to. Looking at the comment above the code shows that it use to write into an element of that pointer where the '&' is appropriate. But now that it writes to the pointer itself, we need to remove the '&' otherwise we write over the pointer and not into the data it points to. Signed-off-by: Steven Rostedt Cc: Marek Belisko Signed-off-by: Greg Kroah-Hartman --- drivers/staging/ft1000/ft1000-usb/ft1000_chdev.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/staging/ft1000/ft1000-usb/ft1000_chdev.c b/drivers/staging/ft1000/ft1000-usb/ft1000_chdev.c index 197b3fb9462e..18c4c15c5aea 100644 --- a/drivers/staging/ft1000/ft1000-usb/ft1000_chdev.c +++ b/drivers/staging/ft1000/ft1000-usb/ft1000_chdev.c @@ -698,7 +698,7 @@ static long ft1000_ChIoctl (struct file *File, unsigned int Command, break; //if ( copy_from_user(&(dpram_command.dpram_blk), (PIOCTL_DPRAM_BLK)Argument, msgsz+2) ) { - if ( copy_from_user(&dpram_data, argp, msgsz+2) ) { + if ( copy_from_user(dpram_data, argp, msgsz+2) ) { DEBUG("FT1000:ft1000_ChIoctl: copy fault occurred\n"); result = -EFAULT; }