lkml.org 
[lkml]   [2018]   [Oct]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v2 0/9] of: fix compatible-child-node lookups
Hi Rob,

On Tue, Sep 04, 2018 at 03:05:57PM +0200, Johan Hovold wrote:
> Hi all,
>
> On Mon, Aug 27, 2018 at 10:21:44AM +0200, Johan Hovold wrote:
> > Several drivers currently use of_find_compatible_node() to lookup child
> > nodes while failing to notice that the of_find_ functions search the
> > entire tree depth-first (from a given start node) and therefore can
> > match unrelated nodes.
> >
> > The fact that these functions also drop a reference to the node they
> > start searching from (e.g. the parent node) is typically also
> > overlooked, something which can lead to use-after-free bugs (e.g. after
> > probe deferrals).
> >
> > This series adds a new helper, similar to of_get_child_by_name(),
> > that can be used to lookup compatible child nodes, and uses the new
> > helper to fix child-node lookups throughout the tree.
> >
> > This is related to the fixes I posted about a year ago, which addressed
> > a similar anti-pattern when looking up child nodes by name. Since it
> > took me more than a year to get all those fixes into Linus' tree (one
> > fix is still pending), and as these fixes depend on the new helper, I'm
> > suggesting that these all go in through Rob's or Greg's trees.
> >
> > Alternatively, the helper could go into to -rc2, and I'll be pinging
> > submaintainers for the coming year as well. ;)
>
> Rob has gotten the helper into -rc2 now:
>
> 36156f9241cb of: add helper to lookup compatible child node
>
> so feel free to pick these fixes up directly for 4.19-rc or -next,
> whichever you prefer. I've been able to trigger crashes after probe
> deferrals due to the use-after-free, but this seems unlikely to be
> exploitable.
>
> I think Rob will be picking up any patches that remain by the end of the
> release cycle for 4.20.

So far only Ulf has picked up the mmc patch below directly, so if you
could take the rest through your tree for -rc1 that would be great.

Thanks,
Johan

> > Johan Hovold (9):
> > of: add helper to lookup compatible child node
> > drm/mediatek: fix OF sibling-node lookup
> > drm/msm: fix OF child-node lookup
> > mmc: meson-mx-sdio: fix OF child-node lookup
> > mtd: nand: atmel: fix OF child-node lookup
> > net: bcmgenet: fix OF child-node lookup
> > net: stmmac: dwmac-sun8i: fix OF child-node lookup
> > NFC: nfcmrvl_uart: fix OF child-node lookup
> > power: supply: twl4030-charger: fix OF sibling-node lookup
> >
> > drivers/gpu/drm/mediatek/mtk_hdmi.c | 5 ++--
> > drivers/gpu/drm/msm/adreno/adreno_gpu.c | 5 ++--
> > drivers/mmc/host/meson-mx-sdio.c | 8 ++++--
> > drivers/mtd/nand/raw/atmel/nand-controller.c | 11 +++++---
> > drivers/net/ethernet/broadcom/genet/bcmmii.c | 2 +-
> > .../net/ethernet/stmicro/stmmac/dwmac-sun8i.c | 12 +++++++--
> > drivers/nfc/nfcmrvl/uart.c | 5 ++--
> > drivers/of/base.c | 25 +++++++++++++++++++
> > drivers/power/supply/twl4030_charger.c | 5 ++--
> > include/linux/of.h | 8 ++++++
> > 10 files changed, 68 insertions(+), 18 deletions(-)

\
 
 \ /
  Last update: 2018-10-23 11:21    [W:0.155 / U:0.156 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site