From: Alain Knaff <alain@knaff.lu>
Date: Tue, 11 Nov 2008 01:08:08 +0000 (-0800)
Subject: vfs: lseek(fd, 0, SEEK_CUR) race condition
X-Git-Tag: v2.6.29-rc1~506^2~12
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5b6f1eb97d462a45be3b30759758b5fdbb562c8c;p=pandora-kernel.git

vfs: lseek(fd, 0, SEEK_CUR) race condition

This patch fixes a race condition in lseek. While it is expected that
unpredictable behaviour may result while repositioning the offset of a
file descriptor concurrently with reading/writing to the same file
descriptor, this should not happen when merely *reading* the file
descriptor's offset.

Unfortunately, the only portable way in Unix to read a file
descriptor's offset is lseek(fd, 0, SEEK_CUR); however executing this
concurrently with read/write may mess up the position.

[with fixes from akpm]

Signed-off-by: Alain Knaff <alain@knaff.lu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---

Reading git-diff-tree failed