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(-)
