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 --- drivers/accessibility/speakup/utils.h | 102 ++++++++++++++++++++++++++++++++++ 1 file changed, 102 insertions(+) create mode 100644 drivers/accessibility/speakup/utils.h (limited to 'drivers/accessibility/speakup/utils.h') diff --git a/drivers/accessibility/speakup/utils.h b/drivers/accessibility/speakup/utils.h new file mode 100644 index 000000000..db00c962f --- /dev/null +++ b/drivers/accessibility/speakup/utils.h @@ -0,0 +1,102 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* utils.h + * originally written by: Kirk Reiser. + * + ** Copyright (C) 2002 Kirk Reiser. + * Copyright (C) 2003 David Borowski. + */ + +#include + +#define MAXKEYS 512 +#define MAXKEYVAL 160 +#define HASHSIZE 101 +#define is_shift -3 +#define is_spk -2 +#define is_input -1 + +struct st_key { + char *name; + struct st_key *next; + int value, shift; +}; + +struct st_key key_table[MAXKEYS]; +struct st_key *extra_keys = key_table+HASHSIZE; +char *def_name, *def_val; +FILE *infile; +int lc; + +char filename[256]; + +static inline void open_input(const char *dir_name, const char *name) +{ + if (dir_name) + snprintf(filename, sizeof(filename), "%s/%s", dir_name, name); + else + snprintf(filename, sizeof(filename), "%s", name); + infile = fopen(filename, "r"); + if (!infile) { + fprintf(stderr, "can't open %s\n", filename); + exit(1); + } + lc = 0; +} + +static inline int oops(const char *msg, const char *info) +{ + if (info == NULL) + info = ""; + fprintf(stderr, "error: file %s line %d\n", filename, lc); + fprintf(stderr, "%s %s\n", msg, info); + exit(1); +} + +static inline struct st_key *hash_name(char *name) +{ + unsigned char *pn = (unsigned char *)name; + int hash = 0; + + while (*pn) { + hash = (hash * 17) & 0xfffffff; + if (isupper(*pn)) + *pn = tolower(*pn); + hash += (int)*pn; + pn++; + } + hash %= HASHSIZE; + return &key_table[hash]; +} + +static inline struct st_key *find_key(char *name) +{ + struct st_key *this = hash_name(name); + + while (this) { + if (this->name && !strcmp(name, this->name)) + return this; + this = this->next; + } + return this; +} + +static inline struct st_key *add_key(char *name, int value, int shift) +{ + struct st_key *this = hash_name(name); + + if (extra_keys-key_table >= MAXKEYS) + oops("out of key table space, enlarge MAXKEYS", NULL); + if (this->name != NULL) { + while (this->next) { + if (!strcmp(name, this->name)) + oops("attempt to add duplicate key", name); + this = this->next; + } + this->next = extra_keys++; + this = this->next; + } + this->name = strdup(name); + this->value = value; + this->shift = shift; + return this; +} -- cgit v1.3.1