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@redhat.com Tested-by: Dave Young hidave.darkstar@gmail.com Acked-by: James Morris jmorris@namei.org Cc: Dave Airlie airlied@gmail.com Cc: Alex Riesen raa.lkml@gmail.com Cc: Sedat Dilek sedat.dilek@googlemail.com Cc: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Chris Wright chrisw@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;