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| author | Shivank Garg <shivankg@amd.com> | 2026-08-22 19:22:05 +0000 |
|---|---|---|
| committer | Vinod Koul <vkoul@kernel.org> | 2026-09-09 17:51:44 +0530 |
| commit | e873c74132f0c5f1452816cd9bb26208f0bba1e1 (patch) | |
| tree | cc1ce1567f5b982359331863ebd9da38741f8d2e /lib/842/842_debugfs.h | |
| download | linux-stable-e873c74132f0c5f1452816cd9bb26208f0bba1e1.tar.gz linux-stable-e873c74132f0c5f1452816cd9bb26208f0bba1e1.zip | |
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 'lib/842/842_debugfs.h')
| -rw-r--r-- | lib/842/842_debugfs.h | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/lib/842/842_debugfs.h b/lib/842/842_debugfs.h new file mode 100644 index 000000000..4469407c3 --- /dev/null +++ b/lib/842/842_debugfs.h @@ -0,0 +1,50 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef __842_DEBUGFS_H__ +#define __842_DEBUGFS_H__ + +#include <linux/debugfs.h> + +static bool sw842_template_counts; +module_param_named(template_counts, sw842_template_counts, bool, 0444); + +static atomic_t template_count[OPS_MAX], template_repeat_count, + template_zeros_count, template_short_data_count, template_end_count; + +static struct dentry *sw842_debugfs_root; + +static int __init sw842_debugfs_create(void) +{ + umode_t m = S_IRUGO | S_IWUSR; + int i; + + if (!debugfs_initialized()) + return -ENODEV; + + sw842_debugfs_root = debugfs_create_dir(MODULE_NAME, NULL); + + for (i = 0; i < ARRAY_SIZE(template_count); i++) { + char name[32]; + + snprintf(name, 32, "template_%02x", i); + debugfs_create_atomic_t(name, m, sw842_debugfs_root, + &template_count[i]); + } + debugfs_create_atomic_t("template_repeat", m, sw842_debugfs_root, + &template_repeat_count); + debugfs_create_atomic_t("template_zeros", m, sw842_debugfs_root, + &template_zeros_count); + debugfs_create_atomic_t("template_short_data", m, sw842_debugfs_root, + &template_short_data_count); + debugfs_create_atomic_t("template_end", m, sw842_debugfs_root, + &template_end_count); + + return 0; +} + +static void __exit sw842_debugfs_remove(void) +{ + debugfs_remove_recursive(sw842_debugfs_root); +} + +#endif |