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/unicode/utf8n.h | 83 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 83 insertions(+) create mode 100644 fs/unicode/utf8n.h (limited to 'fs/unicode/utf8n.h') diff --git a/fs/unicode/utf8n.h b/fs/unicode/utf8n.h new file mode 100644 index 000000000..fc703aa4b --- /dev/null +++ b/fs/unicode/utf8n.h @@ -0,0 +1,83 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (c) 2014 SGI. + * All rights reserved. + */ + +#ifndef UTF8NORM_H +#define UTF8NORM_H + +#include +#include +#include +#include +#include + +int utf8version_is_supported(const struct unicode_map *um, unsigned int version); + +/* + * Determine the length of the normalized from of the string, + * excluding any terminating NULL byte. + * Returns 0 if only ignorable code points are present. + * Returns -1 if the input is not valid UTF-8. + */ +ssize_t utf8nlen(const struct unicode_map *um, enum utf8_normalization n, + const char *s, size_t len); + +/* Needed in struct utf8cursor below. */ +#define UTF8HANGULLEAF (12) + +/* + * Cursor structure used by the normalizer. + */ +struct utf8cursor { + const struct unicode_map *um; + enum utf8_normalization n; + const char *s; + const char *p; + const char *ss; + const char *sp; + unsigned int len; + unsigned int slen; + short int ccc; + short int nccc; + unsigned char hangul[UTF8HANGULLEAF]; +}; + +/* + * Initialize a utf8cursor to normalize a string. + * Returns 0 on success. + * Returns -1 on failure. + */ +int utf8ncursor(struct utf8cursor *u8c, const struct unicode_map *um, + enum utf8_normalization n, const char *s, size_t len); + +/* + * Get the next byte in the normalization. + * Returns a value > 0 && < 256 on success. + * Returns 0 when the end of the normalization is reached. + * Returns -1 if the string being normalized is not valid UTF-8. + */ +extern int utf8byte(struct utf8cursor *u8c); + +struct utf8data { + unsigned int maxage; + unsigned int offset; +}; + +struct utf8data_table { + const unsigned int *utf8agetab; + int utf8agetab_size; + + const struct utf8data *utf8nfdicfdata; + int utf8nfdicfdata_size; + + const struct utf8data *utf8nfdidata; + int utf8nfdidata_size; + + const unsigned char *utf8data; +}; + +extern const struct utf8data_table utf8_data_table; + +#endif /* UTF8NORM_H */ -- cgit v1.3.1