lkml.org 
[lkml]   [2015]   [Feb]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v2] PCI/AER: Avoid info leak in __print_tlp_header
Date
Commit fab4c256a58b ("PCI/AER: Add a TLP header print helper")
introduced the helper function __print_tlp_header, but contrary to the
intention, the behaviour did change: Since we're taking the address of
the parameter t, the first 4 or 8 bytes printed will be the value of
the pointer t itself, and the remaining 12 or 8 bytes will be
who-knows-what (something from the stack).

We want to show the values of the four members of the struct
aer_header_log_regs; that can be done without ugly and error-prone
casts. On little-endian this should produce the same output as
originally intended, and since no-one has complained about getting
garbage output so far, I think big-endian should be ok too.

Fixes: fab4c256a58b ("PCI/AER: Add a TLP header print helper")
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
---
v2: Just print ->dwX as-is.

drivers/pci/pcie/aer/aerdrv_errprint.c | 12 ++----------
1 file changed, 2 insertions(+), 10 deletions(-)

diff --git a/drivers/pci/pcie/aer/aerdrv_errprint.c b/drivers/pci/pcie/aer/aerdrv_errprint.c
index c6849d9e86ce..167fe411ce2e 100644
--- a/drivers/pci/pcie/aer/aerdrv_errprint.c
+++ b/drivers/pci/pcie/aer/aerdrv_errprint.c
@@ -132,16 +132,8 @@ static const char *aer_agent_string[] = {
static void __print_tlp_header(struct pci_dev *dev,
struct aer_header_log_regs *t)
{
- unsigned char *tlp = (unsigned char *)&t;
-
- dev_err(&dev->dev, " TLP Header:"
- " %02x%02x%02x%02x %02x%02x%02x%02x"
- " %02x%02x%02x%02x %02x%02x%02x%02x\n",
- *(tlp + 3), *(tlp + 2), *(tlp + 1), *tlp,
- *(tlp + 7), *(tlp + 6), *(tlp + 5), *(tlp + 4),
- *(tlp + 11), *(tlp + 10), *(tlp + 9),
- *(tlp + 8), *(tlp + 15), *(tlp + 14),
- *(tlp + 13), *(tlp + 12));
+ dev_err(&dev->dev, " TLP Header: %08x %08x %08x %08x\n",
+ t->dw0, t->dw1, t->dw2, t->dw3);
}

static void __aer_print_error(struct pci_dev *dev,
--
2.1.3


\
 
 \ /
  Last update: 2015-02-26 10:01    [W:0.064 / U:0.468 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site