Commit a628e7b8 authored by Chris Wright's avatar Chris Wright Committed by James Morris
Browse files

pci: use security_capable() when checking capablities during config space read

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 de139a33

 ("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: default avatarEric Paris <>
Tested-by: default avatarDave Young <>
Acked-by: default avatarJames Morris <>
Cc: Dave Airlie <>
Cc: Alex Riesen <>
Cc: Sedat Dilek <>
Cc: Linus Torvalds <>
Signed-off-by: default avatarChris Wright <>
Signed-off-by: default avatarJames Morris <>
parent 795abaf1
......@@ -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;
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