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 --- lib/crypto/poly1305.c | 100 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 100 insertions(+) create mode 100644 lib/crypto/poly1305.c (limited to 'lib/crypto/poly1305.c') diff --git a/lib/crypto/poly1305.c b/lib/crypto/poly1305.c new file mode 100644 index 000000000..f313ccc4b --- /dev/null +++ b/lib/crypto/poly1305.c @@ -0,0 +1,100 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Poly1305 authenticator algorithm, RFC7539 + * + * Copyright (C) 2015 Martin Willi + * + * Based on public domain code by Andrew Moon and Daniel J. Bernstein. + */ + +#include +#include +#include +#include +#include +#include + +#ifdef CONFIG_CRYPTO_LIB_POLY1305_ARCH +#include "poly1305.h" /* $(SRCARCH)/poly1305.h */ +#else +#define poly1305_block_init poly1305_block_init_generic +#define poly1305_blocks poly1305_blocks_generic +#define poly1305_emit poly1305_emit_generic +#endif + +void poly1305_init(struct poly1305_desc_ctx *desc, + const u8 key[POLY1305_KEY_SIZE]) +{ + desc->s[0] = get_unaligned_le32(key + 16); + desc->s[1] = get_unaligned_le32(key + 20); + desc->s[2] = get_unaligned_le32(key + 24); + desc->s[3] = get_unaligned_le32(key + 28); + desc->buflen = 0; + poly1305_block_init(&desc->state, key); +} +EXPORT_SYMBOL(poly1305_init); + +void poly1305_update(struct poly1305_desc_ctx *desc, + const u8 *src, unsigned int nbytes) +{ + if (desc->buflen + nbytes >= POLY1305_BLOCK_SIZE) { + unsigned int bulk_len; + + if (desc->buflen) { + unsigned int l = POLY1305_BLOCK_SIZE - desc->buflen; + + memcpy(&desc->buf[desc->buflen], src, l); + src += l; + nbytes -= l; + + poly1305_blocks(&desc->state, desc->buf, + POLY1305_BLOCK_SIZE, 1); + desc->buflen = 0; + } + + bulk_len = round_down(nbytes, POLY1305_BLOCK_SIZE); + nbytes %= POLY1305_BLOCK_SIZE; + + if (bulk_len) { + poly1305_blocks(&desc->state, src, bulk_len, 1); + src += bulk_len; + } + } + if (nbytes) { + memcpy(&desc->buf[desc->buflen], src, nbytes); + desc->buflen += nbytes; + } +} +EXPORT_SYMBOL(poly1305_update); + +void poly1305_final(struct poly1305_desc_ctx *desc, u8 *dst) +{ + if (unlikely(desc->buflen)) { + desc->buf[desc->buflen++] = 1; + memset(desc->buf + desc->buflen, 0, + POLY1305_BLOCK_SIZE - desc->buflen); + poly1305_blocks(&desc->state, desc->buf, POLY1305_BLOCK_SIZE, + 0); + } + + poly1305_emit(&desc->state.h, dst, desc->s); + *desc = (struct poly1305_desc_ctx){}; +} +EXPORT_SYMBOL(poly1305_final); + +#ifdef poly1305_mod_init_arch +static int __init poly1305_mod_init(void) +{ + poly1305_mod_init_arch(); + return 0; +} +subsys_initcall(poly1305_mod_init); + +static void __exit poly1305_mod_exit(void) +{ +} +module_exit(poly1305_mod_exit); +#endif + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("Poly1305 authenticator algorithm, RFC7539"); -- cgit v1.3.1