From: Andrey Mirkin <amirkin@openvz.org>
Date: Thu, 7 Dec 2006 04:31:35 +0000 (-0800)
Subject: [PATCH] skip data conversion in compat_sys_mount when data_page is NULL
X-Git-Tag: v2.6.20-rc1~145^2^2~360
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=822191a2fa1584a29c3224ab328507adcaeac1ab;p=pandora-kernel.git

[PATCH] skip data conversion in compat_sys_mount when data_page is NULL

OpenVZ Linux kernel team has found a problem with mounting in compat mode.

Simple command "mount -t smbfs ..." on Fedora Core 5 distro in 32-bit mode
leads to oops:

  Unable to handle kernel NULL pointer dereference at 0000000000000000 RIP: compat_sys_mount+0xd6/0x290
  Process mount (pid: 14656, veid=300, threadinfo ffff810034d30000, task ffff810034c86bc0)
  Call Trace: ia32_sysret+0x0/0xa

The problem is that data_page pointer can be NULL, so we should skip data
conversion in this case.

Signed-off-by: Andrey Mirkin <amirkin@openvz.org>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---

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