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 --- tools/include/generated/asm-offsets.h | 0 tools/include/generated/asm/cpucap-defs.h | 0 tools/include/generated/asm/sysreg-defs.h | 0 3 files changed, 0 insertions(+), 0 deletions(-) create mode 100644 tools/include/generated/asm-offsets.h create mode 100644 tools/include/generated/asm/cpucap-defs.h create mode 100644 tools/include/generated/asm/sysreg-defs.h (limited to 'tools/include/generated') diff --git a/tools/include/generated/asm-offsets.h b/tools/include/generated/asm-offsets.h new file mode 100644 index 000000000..e69de29bb diff --git a/tools/include/generated/asm/cpucap-defs.h b/tools/include/generated/asm/cpucap-defs.h new file mode 100644 index 000000000..e69de29bb diff --git a/tools/include/generated/asm/sysreg-defs.h b/tools/include/generated/asm/sysreg-defs.h new file mode 100644 index 000000000..e69de29bb -- cgit v1.3.1