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 --- rust/syn/verbatim.rs | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) create mode 100644 rust/syn/verbatim.rs (limited to 'rust/syn/verbatim.rs') diff --git a/rust/syn/verbatim.rs b/rust/syn/verbatim.rs new file mode 100644 index 000000000..97bc08f70 --- /dev/null +++ b/rust/syn/verbatim.rs @@ -0,0 +1,35 @@ +// SPDX-License-Identifier: Apache-2.0 OR MIT + +use crate::parse::ParseStream; +use proc_macro2::{Delimiter, TokenStream}; +use std::cmp::Ordering; +use std::iter; + +pub(crate) fn between<'a>(begin: ParseStream<'a>, end: ParseStream<'a>) -> TokenStream { + let end = end.cursor(); + let mut cursor = begin.cursor(); + assert!(crate::buffer::same_buffer(end, cursor)); + + let mut tokens = TokenStream::new(); + while cursor != end { + let (tt, next) = cursor.token_tree().unwrap(); + + if crate::buffer::cmp_assuming_same_buffer(end, next) == Ordering::Less { + // A syntax node can cross the boundary of a None-delimited group + // due to such groups being transparent to the parser in most cases. + // Any time this occurs the group is known to be semantically + // irrelevant. https://github.com/dtolnay/syn/issues/1235 + if let Some((inside, _span, after)) = cursor.group(Delimiter::None) { + assert!(next == after); + cursor = inside; + continue; + } else { + panic!("verbatim end must not be inside a delimited group"); + } + } + + tokens.extend(iter::once(tt)); + cursor = next; + } + tokens +} -- cgit v1.3.1