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/nh.c | 82 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 82 insertions(+) create mode 100644 lib/crypto/nh.c (limited to 'lib/crypto/nh.c') diff --git a/lib/crypto/nh.c b/lib/crypto/nh.c new file mode 100644 index 000000000..e1d0095b5 --- /dev/null +++ b/lib/crypto/nh.c @@ -0,0 +1,82 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright 2018 Google LLC + */ + +/* + * Implementation of the NH almost-universal hash function, specifically the + * variant of NH used in Adiantum. This is *not* a cryptographic hash function. + * + * Reference: section 6.3 of "Adiantum: length-preserving encryption for + * entry-level processors" (https://eprint.iacr.org/2018/720.pdf). + */ + +#include +#include +#include +#include +#include + +#ifdef CONFIG_CRYPTO_LIB_NH_ARCH +#include "nh.h" /* $(SRCARCH)/nh.h */ +#else +static bool nh_arch(const u32 *key, const u8 *message, size_t message_len, + __le64 hash[NH_NUM_PASSES]) +{ + return false; +} +#endif + +void nh(const u32 *key, const u8 *message, size_t message_len, + __le64 hash[NH_NUM_PASSES]) +{ + u64 sums[4] = { 0, 0, 0, 0 }; + + if (nh_arch(key, message, message_len, hash)) + return; + + static_assert(NH_PAIR_STRIDE == 2); + static_assert(NH_NUM_PASSES == 4); + + while (message_len) { + u32 m0 = get_unaligned_le32(message + 0); + u32 m1 = get_unaligned_le32(message + 4); + u32 m2 = get_unaligned_le32(message + 8); + u32 m3 = get_unaligned_le32(message + 12); + + sums[0] += (u64)(u32)(m0 + key[0]) * (u32)(m2 + key[2]); + sums[1] += (u64)(u32)(m0 + key[4]) * (u32)(m2 + key[6]); + sums[2] += (u64)(u32)(m0 + key[8]) * (u32)(m2 + key[10]); + sums[3] += (u64)(u32)(m0 + key[12]) * (u32)(m2 + key[14]); + sums[0] += (u64)(u32)(m1 + key[1]) * (u32)(m3 + key[3]); + sums[1] += (u64)(u32)(m1 + key[5]) * (u32)(m3 + key[7]); + sums[2] += (u64)(u32)(m1 + key[9]) * (u32)(m3 + key[11]); + sums[3] += (u64)(u32)(m1 + key[13]) * (u32)(m3 + key[15]); + key += NH_MESSAGE_UNIT / sizeof(key[0]); + message += NH_MESSAGE_UNIT; + message_len -= NH_MESSAGE_UNIT; + } + + hash[0] = cpu_to_le64(sums[0]); + hash[1] = cpu_to_le64(sums[1]); + hash[2] = cpu_to_le64(sums[2]); + hash[3] = cpu_to_le64(sums[3]); +} +EXPORT_SYMBOL_GPL(nh); + +#ifdef nh_mod_init_arch +static int __init nh_mod_init(void) +{ + nh_mod_init_arch(); + return 0; +} +subsys_initcall(nh_mod_init); + +static void __exit nh_mod_exit(void) +{ +} +module_exit(nh_mod_exit); +#endif + +MODULE_DESCRIPTION("NH almost-universal hash function"); +MODULE_LICENSE("GPL"); -- cgit v1.3.1