On Sun, Dec 18, 2022 at 03:21:39PM +0300, Alexey V. Vissarionov wrote:
> On 2022-12-18 19:57:02 +0900, Krzysztof Wilczyński wrote:
>
> > Thank you for sending the patch over! However, if possible,
> > can you send it as plain text without any multi-part MIME
> > involved?
>
> ACK.
>
> > If possible, it would be nice to mention that this needed
> > to make sure that there is enough space to correctly
> > NULL-terminate the ID string.
>
> ACK.
>
> So, here goes the corrected text:
>
> Although unlikely, the 'id' value may be as big as 4294967295
> (uint32_max) and "virtfn4294967295\0" would require 17 bytes
> instead of 16 to make sure that buffer has enough space to
> properly NULL-terminate the ID string.
>
> Found by Linux Verification Center (linuxtesting.org) with SVACE.
>
> Fixes: dd7cc44d0 ("PCI: add SR-IOV API for Physical Function driver")
> Signed-off-by: Alexey V. Vissarionov <gremlin@xxxxxxxxxxxx>
I collected this up and applied to pci/iov for v6.3 as below. I agree
this is probably only a theoretical issue, but it's easier to spend a
byte of stack space than to prove that we don't need to.
Bjorn
commit 58d4c63d0a27 ("PCI/IOV: Enlarge virtfn sysfs name buffer")
parent 1b929c02afd3
Author: Alexey V. Vissarionov <gremlin@xxxxxxxxxxxx>
Date: Sun Dec 18 06:33:47 2022 +0300
PCI/IOV: Enlarge virtfn sysfs name buffer
The sysfs link name "virtfn%u" constructed by pci_iov_sysfs_link() requires
17 bytes to contain the longest possible string. Increase VIRTFN_ID_LEN to
accommodate that.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
[bhelgaas: commit log, comment at #define]
Fixes: dd7cc44d0 ("PCI: add SR-IOV API for Physical Function driver")
Link: https://lore.kernel.org/r/20221218033347.23743-1-gremlin@xxxxxxxxxxxx
Signed-off-by: Alexey V. Vissarionov <gremlin@xxxxxxxxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index 952217572113..b2e8322755c1 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -14,7 +14,7 @@
#include <linux/delay.h>
#include "pci.h"
-#define VIRTFN_ID_LEN 16
+#define VIRTFN_ID_LEN 17 /* "virtfn%u\0" for 2^32 - 1 */
int pci_iov_virtfn_bus(struct pci_dev *dev, int vf_id)
{
