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 --- fs/coda/sysctl.c | 53 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 53 insertions(+) create mode 100644 fs/coda/sysctl.c (limited to 'fs/coda/sysctl.c') diff --git a/fs/coda/sysctl.c b/fs/coda/sysctl.c new file mode 100644 index 000000000..0df46f09b --- /dev/null +++ b/fs/coda/sysctl.c @@ -0,0 +1,53 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Sysctl operations for Coda filesystem + * Original version: (C) 1996 P. Braam and M. Callahan + * Rewritten for Linux 2.1. (C) 1997 Carnegie Mellon University + * + * Carnegie Mellon encourages users to contribute improvements to + * the Coda project. Contact Peter Braam (coda@cs.cmu.edu). + */ + +#include + +#include "coda_int.h" + +static struct ctl_table_header *fs_table_header; + +static const struct ctl_table coda_table[] = { + { + .procname = "timeout", + .data = &coda_timeout, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec + }, + { + .procname = "hard", + .data = &coda_hard, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec + }, + { + .procname = "fake_statfs", + .data = &coda_fake_statfs, + .maxlen = sizeof(int), + .mode = 0600, + .proc_handler = proc_dointvec + }, +}; + +void coda_sysctl_init(void) +{ + if ( !fs_table_header ) + fs_table_header = register_sysctl("coda", coda_table); +} + +void coda_sysctl_clean(void) +{ + if ( fs_table_header ) { + unregister_sysctl_table(fs_table_header); + fs_table_header = NULL; + } +} -- cgit v1.3.1