On Thu, Mar 07, 2024 at 04:36:06PM -0600, Bjorn Helgaas wrote: > [+cc Hannes, who did a lot of related VPD work and reviewed the > original posting at > https://lore.kernel.org/r/20210715215959.2014576-6-helgaas@xxxxxxxxxx/] > > On Thu, Mar 07, 2024 at 05:09:27PM +0100, Josselin Mouette wrote: > > When a device returns invalid VPD data, it can be misused by other > > code paths in kernel space or user space, and there are instances > > in which this seems to cause memory corruption. > > More of the background from Josselin at > https://lore.kernel.org/r/aaea0b30c35bb73b947727e4b3ec354d6b5c399c.camel@xxxxxxxxxx > > This is a regression, and obviously needs to be fixed somehow, but I'm > a bit hesitant to revert this until we understand the problem better. > If there's a memory corruption lurking and a revert hides the > corruption so we never fix it, I'm not sure that's an improvement > overall. I don't want to drop this, but we're kind of stuck here: - I'd still like to understand the problem better. - Trivially, I can't apply patches lacking the appropriate signed-off-by; see https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?id=v6.6#n396 > > There is no sensible reason why the kernel would provide userspace > > or drivers with invalid and potentially dangerous data. > > > > This reverts commit 5fe204eab174fd474227f23fd47faee4e7a6c000. > > --- > > drivers/pci/vpd.c | 6 +++--- > > 1 file changed, 3 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/pci/vpd.c b/drivers/pci/vpd.c > > index 485a642b9304..daaa208c9d9c 100644 > > --- a/drivers/pci/vpd.c > > +++ b/drivers/pci/vpd.c > > @@ -68,7 +68,7 @@ static size_t pci_vpd_size(struct pci_dev *dev) > > if (pci_read_vpd_any(dev, off + 1, 2, > > &header[1]) != 2) { > > pci_warn(dev, "failed VPD read at > > offset %zu\n", > > off + 1); > > - return off ?: PCI_VPD_SZ_INVALID; > > + return PCI_VPD_SZ_INVALID; > > } > > size = pci_vpd_lrdt_size(header); > > if (off + size > PCI_VPD_MAX_SIZE) > > @@ -87,13 +87,13 @@ static size_t pci_vpd_size(struct pci_dev *dev) > > return off; > > } > > } > > - return off; > > + return PCI_VPD_SZ_INVALID; > > > > error: > > pci_info(dev, "invalid VPD tag %#04x (size %zu) at offset > > %zu%s\n", > > header[0], size, off, off == 0 ? > > "; assume missing optional EEPROM" : ""); > > - return off ?: PCI_VPD_SZ_INVALID; > > + return PCI_VPD_SZ_INVALID; > > } > > > > static bool pci_vpd_available(struct pci_dev *dev, bool check_size) > > -- > > 2.39.2 > >
