Re: [PATCH v4 0/9] PCI: Fix UAF and TOCTOU related to dynamic ID
Masanori Goto <[email protected]> Sat, 1 Aug 2026 12:13:18 +0900
| Newsgroups | org.kernel.vger.linux-ide,dev.linux.lists.driver-core,org.freedesktop.lists.dri-devel,org.kernel.vger.linux-kernel,org.kernel.vger.linux-pci,org.kernel.vger.linux-scsi,org.kernel.vger.netdev |
|---|---|
| Message-ID | <CALZLnaEmm5Zi=30n4i7ioX9ii4KMAePnZTAhAcNScSZFSNB7UA@mail.gmail.com> |
I'm a "nsp32 folk", which patch version should I take a look at?
Best regards,
Masanori
2026=E5=B9=B47=E6=9C=8829=E6=97=A5(=E6=B0=B4) 1:27 Bjorn Helgaas <helgaas@k=
ernel.org>:
>
> On Thu, Jul 23, 2026 at 11:00:39PM +0100, Gary Guo wrote:
> > While working on improving the Rust abstractions [1], Sashiko reported =
that
> > an existing UAF issue related to dynamic ID, which I find to be genuine=
.
> > When taking a look at the code I also find a TOCTOU issue where the
> > existence check of dynamic ID happens in a separate critical section as=
the
> > actual insertion. This series fix both issues.
> >
> > There are two exported functions pci_match_id() and pci_add_dynid() whi=
ch I
> > have to tweak to implement this cleanly; I created separate "do_xxx"
> > functions to keep the existing APIs because they all have multiple user=
s.
> >
> > There're a few existing users which stores their pci_device_id argument=
in
> > probe callback. This is a bad pattern because nothing except driver_dat=
a
> > inside pci_device_id is what they want; actual ID information can be
> > retrieved from pci_dev instead.
> >
> > There are two users that performs pointer arithmetic on the pci_device_=
id;
> > these are also problematic with dynamic ID and driver_override, so fix =
them
> > as well.
> >
> > I've used the following coccinelle script to flag all cases where the
> > pci_device_id is used other than reading its fields.
> >
> > @usage@
> > identifier fn, id;
> > position p;
> > @@
> > fn(..., struct pci_device_id *id, ...)
> > {
> > ...
> > id@p
> > ...
> > }
> >
> > // Due to cocci isomorphism this needs to be explicit
> > @bad@
> > identifier fn, id;
> > type T;
> > position usage.p;
> > @@
> > fn(..., struct pci_device_id *id, ...)
> > {
> > ...
> > (T*)id@p
> > ...
> > }
> >
> > // Good use cases
> > @good@
> > identifier fn, id, fld;
> > expression E;
> > position usage.p;
> > @@
> > fn(..., struct pci_device_id *id, ...)
> > {
> > ...
> > (
> > id@p->fld
> > |
> > E(..., id@p, ...)
> > |
> > // Redundant checks, but ignore
> > !id@p
> > |
> > // Redundant checks, but ignore
> > id ? ... : ...
> > )
> > ...
> > }
> >
> > @script:python depends on usage && (bad || !good)@
> > p << usage.p;
> > @@
> > coccilib.report.print_report(p[0], "suspicious use of pci_device_id")
> >
> > Link: https://lore.kernel.org/all/20260618-id_info-v1-0-96af1e559ef9@ga=
ryguo.net/ [1]
> > Link: https://lore.kernel.org/all/[email protected]=
el.org/ [2]
> >
> > ---
> > Changes in v4:
> > - Code and commit message style fixes (Bjorn)
> > - Link to v3: https://patch.msgid.link/20260706-pci_id_fix-v3-0-2d48fc0=
[email protected]
> >
> > Changes in v3:
> > - Fix users which uses pci_device_id for pointer arithmetic. (Sashiko)
> > - Convert to scoped_guard. (Danilo)
> > - For static IDs, still give out static pointers and avoid making a cop=
y.
> > - Link to v2: https://patch.msgid.link/20260630-pci_id_fix-v2-0-b834a98=
[email protected]
> >
> > Changes in v2:
> > - Fix users which store pci_device_id.
> > - Clarify in probe documentation about the lifetime of pci_device_id
> > parameter.
> > - Dynamic ID conflict check now ignores override_only. (Sashiko)
> > - Link to v1: https://patch.msgid.link/20260626-pci_id_fix-v1-0-a35c803=
[email protected]
> >
> > ---
> > Gary Guo (9):
> > ata: ata_generic: don't store pci_device_id
> > scsi: nsp32: don't store pci_device_id
> > ipack: tpci200: don't store pci_device_id
> > mlxsw: pci: don't store pci_device_id
> > agp/via: Don't rely on address of pci_device_id
> > agp/amd-k7: Don't rely on address of pci_device_id
> > PCI: Make pci_match_one_device() match on ID instead of device
> > PCI: Fix dyn_id add TOCTOU
> > PCI: Fix UAF when probe runs concurrent to dyn ID removal
> >
> > drivers/ata/ata_generic.c | 6 +-
> > drivers/char/agp/amd-k7-agp.c | 26 +--
> > drivers/char/agp/via-agp.c | 308 +++++++---------------=
--------
> > drivers/ipack/carriers/tpci200.c | 1 -
> > drivers/ipack/carriers/tpci200.h | 1 -
> > drivers/net/ethernet/mellanox/mlxsw/pci.c | 11 +-
> > drivers/pci/pci-driver.c | 194 ++++++++++---------
> > drivers/pci/pci.h | 43 +++--
> > drivers/pci/search.c | 8 +-
> > drivers/scsi/nsp32.c | 8 +-
> > drivers/scsi/nsp32.h | 8 +-
> > include/linux/pci.h | 1 +
> > 12 files changed, 237 insertions(+), 378 deletions(-)
>
> I put this on pci/enumeration and plan it for v7.3, hopefully with
> acks from the AGP, tpci200, and nsp32 folks.