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 --- Documentation/ABI/testing/procfs-attr-exec | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) create mode 100644 Documentation/ABI/testing/procfs-attr-exec (limited to 'Documentation/ABI/testing/procfs-attr-exec') diff --git a/Documentation/ABI/testing/procfs-attr-exec b/Documentation/ABI/testing/procfs-attr-exec new file mode 100644 index 000000000..34593866a --- /dev/null +++ b/Documentation/ABI/testing/procfs-attr-exec @@ -0,0 +1,20 @@ +What: /proc/*/attr/exec +Contact: linux-security-module@vger.kernel.org, + selinux@vger.kernel.org, + apparmor@lists.ubuntu.com +Description: The security information to be used on the process + by a Linux security module (LSM) active on the system + after a subsequent exec() call. + The details of permissions required to read from + this interface and hence obtain the security state + of the task identified is LSM dependent. + A process cannot write to this interface unless it + refers to itself. + The other details of permissions required to write to + this interface and hence change the security state of + the task identified are LSM dependent. + The format of the data used by this interface is LSM + dependent. + SELinux and AppArmor provide this interface. +Users: SELinux user-space + AppArmor user-space -- cgit v1.3.1