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 --- include/crypto/xts.h | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+) create mode 100644 include/crypto/xts.h (limited to 'include/crypto/xts.h') diff --git a/include/crypto/xts.h b/include/crypto/xts.h new file mode 100644 index 000000000..16aef89f0 --- /dev/null +++ b/include/crypto/xts.h @@ -0,0 +1,50 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _CRYPTO_XTS_H +#define _CRYPTO_XTS_H + +#include +#include +#include + +#define XTS_BLOCK_SIZE 16 +#define XTS_FORBID_WEAK_KEYS (1 << 0) + +static inline int __xts_verify_key(const u8 *key, size_t keylen, int flags) +{ + /* + * key consists of keys of equal size concatenated, therefore + * the length must be even. + */ + if (keylen % 2) + return -EINVAL; + + /* + * In FIPS mode only a combined key length of either 256 or + * 512 bits is allowed, c.f. FIPS 140-3 IG C.I. + */ + if (fips_enabled && keylen != 32 && keylen != 64) + return -EINVAL; + + /* + * Ensure that the AES and tweak key are not identical when + * in FIPS mode or the FORBID_WEAK_KEYS flag is set. + */ + if ((fips_enabled || (flags & XTS_FORBID_WEAK_KEYS)) && + !crypto_memneq(key, key + (keylen / 2), keylen / 2)) + return -EINVAL; + + return 0; +} + +static inline int xts_verify_key(struct crypto_skcipher *tfm, const u8 *key, + unsigned int keylen) +{ + int flags = (crypto_skcipher_get_flags(tfm) & + CRYPTO_TFM_REQ_FORBID_WEAK_KEYS) ? + XTS_FORBID_WEAK_KEYS : + 0; + + return __xts_verify_key(key, keylen, flags); +} + +#endif /* _CRYPTO_XTS_H */ -- cgit v1.3.1