From e873c74132f0c5f1452816cd9bb26208f0bba1e1 Mon Sep 17 00:00:00 2001 From: Shivank Garg Date: Sat, 22 Aug 2026 19:22:05 +0000 Subject: dmaengine: fix use-after-free in dma_chan_put() and dma_release_channel() When dma_device_put() drops the last reference on chan->device->ref, dma_device_release() runs and may free the dma_device along with its channels. dma_chan_put() then still reads chan->device->owner via dma_chan_to_owner() for the trailing module_put(). KASAN catches it: slab-use-after-free in dma_chan_put+0x3e6/0x4c0 Read of size 8 by task insmod/6319 Freed by task 6319: kfree+0x225/0x470 dma_chan_put+0x395/0x4c0 dmaengine_put+0xf8/0x160 Cache the module owner in dma_chan_put() before the put so the trailing module_put() does not need chan->device. Fixes: 8ad342a86359 ("dmaengine: Add reference counting to dma_device struct") Suggested-by: Sashiko Link: https://sashiko.dev/#/patchset/20260518-dmaengine-kref-fix-v1-1-4d6125048fb7@amd.com Reviewed-by: Frank Li Reviewed-by: Logan Gunthorpe Signed-off-by: Shivank Garg Link: https://patch.msgid.link/20260822-dmaengine-kref-fix-v5-3-d4a4ee47d927@amd.com Signed-off-by: Vinod Koul --- arch/m68k/Kconfig.debug | 45 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) create mode 100644 arch/m68k/Kconfig.debug (limited to 'arch/m68k/Kconfig.debug') diff --git a/arch/m68k/Kconfig.debug b/arch/m68k/Kconfig.debug new file mode 100644 index 000000000..d036f9038 --- /dev/null +++ b/arch/m68k/Kconfig.debug @@ -0,0 +1,45 @@ +# SPDX-License-Identifier: GPL-2.0 + +config BOOTPARAM + bool "Compiled-in Kernel Boot Parameter" + +config BOOTPARAM_STRING + string "Kernel Boot Parameter" + default "console=ttyS0,19200" + depends on BOOTPARAM + +config EARLY_PRINTK + bool "Early printk" + depends on MMU_MOTOROLA + help + Write kernel log output directly to a serial port. + Where implemented, output goes to the framebuffer as well. + PROM console functionality on Sun 3x is not affected by this option. + + Pass "earlyprintk" on the kernel command line to get a + boot console. + + This is useful for kernel debugging when your machine crashes very + early, i.e. before the normal console driver is loaded. + You should normally say N here, unless you want to debug such a crash. + +if !MMU + +config FULLDEBUG + bool "Full Symbolic/Source Debugging support" + help + Enable debugging symbols on kernel build. + +config HIGHPROFILE + bool "Use fast second timer for profiling" + depends on COLDFIRE + help + Use a fast secondary clock to produce profiling information. + +config BDM_DISABLE + bool "Disable BDM signals" + depends on COLDFIRE + help + Disable the ColdFire CPU's BDM signals. + +endif -- cgit v1.3.1