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authorShivank Garg <shivankg@amd.com>2026-08-22 19:22:05 +0000
committerVinod Koul <vkoul@kernel.org>2026-09-09 17:51:44 +0530
commite873c74132f0c5f1452816cd9bb26208f0bba1e1 (patch)
treecc1ce1567f5b982359331863ebd9da38741f8d2e /arch/x86/Kconfig.assembler
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dmaengine: fix use-after-free in dma_chan_put() and dma_release_channel()grafted
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 <sashiko-bot@kernel.org> Link: https://sashiko.dev/#/patchset/20260518-dmaengine-kref-fix-v1-1-4d6125048fb7@amd.com Reviewed-by: Frank Li <Frank.Li@nxp.com> Reviewed-by: Logan Gunthorpe <logang@deltatee.com> Signed-off-by: Shivank Garg <shivankg@amd.com> Link: https://patch.msgid.link/20260822-dmaengine-kref-fix-v5-3-d4a4ee47d927@amd.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
Diffstat (limited to 'arch/x86/Kconfig.assembler')
-rw-r--r--arch/x86/Kconfig.assembler7
1 files changed, 7 insertions, 0 deletions
diff --git a/arch/x86/Kconfig.assembler b/arch/x86/Kconfig.assembler
new file mode 100644
index 000000000..b1c59fb0a
--- /dev/null
+++ b/arch/x86/Kconfig.assembler
@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (C) 2020 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
+
+config AS_WRUSS
+ def_bool $(as-instr64,wrussq %rax$(comma)(%rbx))
+ help
+ Supported by binutils >= 2.31 and LLVM integrated assembler