This reintroduces commit 47970b1b which was subsequently reverted
as f00eaeea. The original change was broken and caused X startup
failures and generally made privileged processes incapable of reading
device dependent config space. The normal capable() interface returns
true on success, but the LSM interface returns 0 on success. This thinko
is now fixed in this patch, and has been confirmed to work properly.
So, once again...Eric Paris noted that commit de139a3 ("pci: check caps
from sysfs file open to read device dependent config space") caused the
capability check to bypass security modules and potentially auditing.
Rectify this by calling security_capable() when checking the open file's
capabilities for config space reads.
Reported-by: Eric Paris <eparis at redhat.com>
Tested-by: Dave Young <hidave.darkstar at gmail.com>
Acked-by: James Morris <jmorris at namei.org>
Cc: Dave Airlie <airlied at gmail.com>
Cc: Alex Riesen <raa.lkml at gmail.com>
Cc: Sedat Dilek <sedat.dilek at googlemail.com>
Cc: Linus Torvalds <torvalds at linux-foundation.org>
Signed-off-by: Chris Wright <chrisw at sous-sol.org>
---
v2: added Reported-by Eric
v3: fix logic screw up
drivers/pci/pci-sysfs.c | 3 ++-
1 files changed, 2 insertions(+), 1 deletions(-)
diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index 8ecaac9..ea25e5b 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -23,6 +23,7 @@
#include <linux/mm.h>
#include <linux/fs.h>
#include <linux/capability.h>
+#include <linux/security.h>
#include <linux/pci-aspm.h>
#include <linux/slab.h>
#include "pci.h"
@@ -368,7 +369,7 @@ pci_read_config(struct file *filp, struct kobject *kobj,
u8 *data = (u8*) buf;
/* Several chips lock up trying to read undefined config space */
- if (cap_raised(filp->f_cred->cap_effective, CAP_SYS_ADMIN)) {
+ if (security_capable(filp->f_cred, CAP_SYS_ADMIN) == 0) {
size = dev->cfg_size;
} else if (dev->hdr_type == PCI_HEADER_TYPE_CARDBUS) {
size = 128;
--
1.7.3.4
