[4.2.y-ckt stable] Patch "thunderbolt: Fix double free of drom buffer" has been added to the 4.2.y-ckt tree

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    thunderbolt: Fix double free of drom buffer

to the linux-4.2.y-queue branch of the 4.2.y-ckt extended stable tree 
which can be found at:

    https://git.launchpad.net/~canonical-kernel/linux/+git/linux-stable-ckt/log/?h=linux-4.2.y-queue

This patch is scheduled to be released in version 4.2.8-ckt12.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 4.2.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

---8<------------------------------------------------------------

>From 1c6aa0471c8a6d3190018f91975be5cb9f55a795 Mon Sep 17 00:00:00 2001
From: Andreas Noever <andreas.noever at gmail.com>
Date: Sun, 10 Apr 2016 12:48:27 +0200
Subject: thunderbolt: Fix double free of drom buffer

commit 2ffa9a5d76a75abbc1f95c17959fced666095bdd upstream.

If tb_drom_read() fails, sw->drom is freed but not set to NULL.  sw->drom
is then freed again in the error path of tb_switch_alloc().

The bug can be triggered by unplugging a thunderbolt device shortly after
it is detected by the thunderbolt driver.

Clear sw->drom if tb_drom_read() fails.

[bhelgaas: add Fixes:, stable versions of interest]
Fixes: 343fcb8c70d7 ("thunderbolt: Fix nontrivial endpoint devices.")
Signed-off-by: Andreas Noever <andreas.noever at gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas at google.com>
CC: Lukas Wunner <lukas at wunner.de>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/thunderbolt/eeprom.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/thunderbolt/eeprom.c b/drivers/thunderbolt/eeprom.c
index 0dde34e..545c60c 100644
--- a/drivers/thunderbolt/eeprom.c
+++ b/drivers/thunderbolt/eeprom.c
@@ -444,6 +444,7 @@ int tb_drom_read(struct tb_switch *sw)
 	return tb_drom_parse_entries(sw);
 err:
 	kfree(sw->drom);
+	sw->drom = NULL;
 	return -EIO;

 }
--
2.7.4