From: Allen Pais <ap...@linux.microsoft.com>
Access to pci config space is explictly checked with CAP_SYS_ADMIN
in order to read configuration space past the frist 64B.
Since the path is only for reading, could we use CAP_SYS_RAWIO?
This patch contains a simpler fix, I would love to hear from the
Maintainers on the approach.
The other approach that I considered was to introduce and API
which would check for multiple capabilities, something similar to
perfmon_capable()/bpf_capable(). But I could not find more users
for the API and hence dropped it.
The problem I am trying to solve is to avoid handing out
CAP_SYS_ADMIN for extended reads of the PCI config space.
Signed-off-by: Allen Pais <allen.p...@lkml.com>
---
drivers/pci/pci-sysfs.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index 6d78df981d41..6574c0203475 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -666,7 +666,8 @@ static ssize_t pci_read_config(struct file *filp, struct
kobject *kobj,
u8 *data = (u8 *) buf;
/* Several chips lock up trying to read undefined config space */
- if (file_ns_capable(filp, &init_user_ns, CAP_SYS_ADMIN))
+ if (file_ns_capable(filp, &init_user_ns, CAP_SYS_ADMIN) ||
+ file_ns_capable(filp, &init_user_ns, CAP_SYS_RAWIO))
size = dev->cfg_size;
else if (dev->hdr_type == PCI_HEADER_TYPE_CARDBUS)
size = 128;
--
2.25.1
