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 --- scripts/jobserver-exec | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) create mode 100755 scripts/jobserver-exec (limited to 'scripts/jobserver-exec') diff --git a/scripts/jobserver-exec b/scripts/jobserver-exec new file mode 100755 index 000000000..21b319e6c --- /dev/null +++ b/scripts/jobserver-exec @@ -0,0 +1,35 @@ +#!/usr/bin/env python3 +# SPDX-License-Identifier: GPL-2.0+ + +""" +Determines how many parallel tasks "make" is expecting, as it is +not exposed via any special variables, reserves them all, runs a subprocess +with PARALLELISM environment variable set, and releases the jobs back again. + +See: + https://www.gnu.org/software/make/manual/html_node/POSIX-Jobserver.html#POSIX-Jobserver +""" + +import os +import sys + +LIB_DIR = "../tools/lib/python" +SRC_DIR = os.path.dirname(os.path.realpath(__file__)) + +sys.path.insert(0, os.path.join(SRC_DIR, LIB_DIR)) + +from jobserver import JobserverExec # pylint: disable=C0415 + + +def main(): + """Main program""" + if len(sys.argv) < 2: + name = os.path.basename(__file__) + sys.exit("usage: " + name +" command [args ...]\n" + __doc__) + + with JobserverExec() as jobserver: + return jobserver.run(sys.argv[1:]) + + +if __name__ == "__main__": + sys.exit(main()) -- cgit v1.3.1