| From 08398b963d383d22712bc5e24f3ace5227e26a12 Mon Sep 17 00:00:00 2001 |
| From: Al Viro <viro@ZenIV.linux.org.uk> |
| Date: Mon, 20 Aug 2012 15:28:00 +0100 |
| Subject: [PATCH] vfs: missed source of ->f_pos races |
| |
| commit 0e665d5d1125f9f4ccff56a75e814f10f88861a2 upstream. |
| |
| compat_sys_{read,write}v() need the same "pass a copy of file->f_pos" thing |
| as sys_{read,write}{,v}(). |
| |
| Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> |
| Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
| Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> |
| --- |
| fs/compat.c | 10 ++++++++-- |
| 1 file changed, 8 insertions(+), 2 deletions(-) |
| |
| diff --git a/fs/compat.c b/fs/compat.c |
| index 633e63c32aa7..388555d404bf 100644 |
| --- a/fs/compat.c |
| +++ b/fs/compat.c |
| @@ -1231,11 +1231,14 @@ compat_sys_readv(unsigned long fd, const struct compat_iovec __user *vec, |
| struct file *file; |
| int fput_needed; |
| ssize_t ret; |
| + loff_t pos; |
| |
| file = fget_light(fd, &fput_needed); |
| if (!file) |
| return -EBADF; |
| - ret = compat_readv(file, vec, vlen, &file->f_pos); |
| + pos = file->f_pos; |
| + ret = compat_readv(file, vec, vlen, &pos); |
| + file->f_pos = pos; |
| fput_light(file, fput_needed); |
| return ret; |
| } |
| @@ -1288,11 +1291,14 @@ compat_sys_writev(unsigned long fd, const struct compat_iovec __user *vec, |
| struct file *file; |
| int fput_needed; |
| ssize_t ret; |
| + loff_t pos; |
| |
| file = fget_light(fd, &fput_needed); |
| if (!file) |
| return -EBADF; |
| - ret = compat_writev(file, vec, vlen, &file->f_pos); |
| + pos = file->f_pos; |
| + ret = compat_writev(file, vec, vlen, &pos); |
| + file->f_pos = pos; |
| fput_light(file, fput_needed); |
| return ret; |
| } |
| -- |
| 1.8.5.2 |
| |
