lkml.org 
[lkml]   [2016]   [May]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] thunderbolt: Fix double free of drom buffer
On Sun, Apr 10, 2016 at 12:48:27PM +0200, Andreas Noever wrote:
> 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 sw_switch_alloc.

s/sw_switch_alloc/tb_switch_alloc/ ?

> The bug can be triggered by unplugging a thunderbolt device shortly
> after it is detected by the thunderbolt driver.
>
> Signed-off-by: Andreas Noever <andreas.noever@gmail.com>
> Cc: Lukas Wunner <lukas@wunner.de>
> Cc: stable@vger.kernel.org

How far back would this need to be applied? What is the commit where
the but was introduced?

I applied this to pci/thunderbolt for v4.7 with the following
changelog. If I did it wrong, I'll gladly update it, especially if
you have specific symptoms of a bug or oops that would help people
find this fix.

thunderbolt: Fix double free of drom buffer

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@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: stable@vger.kernel.org # v3.17+
CC: Lukas Wunner <lukas@wunner.de>

> ---
> 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;
>
> }
> --
> 2.8.0
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-pci" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html

\
 
 \ /
  Last update: 2016-05-02 20:01    [W:0.048 / U:0.032 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site