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 --- crypto/arc4.c | 82 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 82 insertions(+) create mode 100644 crypto/arc4.c (limited to 'crypto/arc4.c') diff --git a/crypto/arc4.c b/crypto/arc4.c new file mode 100644 index 000000000..160801811 --- /dev/null +++ b/crypto/arc4.c @@ -0,0 +1,82 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Cryptographic API + * + * ARC4 Cipher Algorithm + * + * Jon Oberheide + */ + +#include +#include +#include +#include +#include +#include + +#define ARC4_ALIGN __alignof__(struct arc4_ctx) + +static int crypto_arc4_setkey(struct crypto_lskcipher *tfm, const u8 *in_key, + unsigned int key_len) +{ + struct arc4_ctx *ctx = crypto_lskcipher_ctx(tfm); + + return arc4_setkey(ctx, in_key, key_len); +} + +static int crypto_arc4_crypt(struct crypto_lskcipher *tfm, const u8 *src, + u8 *dst, unsigned nbytes, u8 *siv, u32 flags) +{ + struct arc4_ctx *ctx = crypto_lskcipher_ctx(tfm); + + if (!(flags & CRYPTO_LSKCIPHER_FLAG_CONT)) + memcpy(siv, ctx, sizeof(*ctx)); + + ctx = (struct arc4_ctx *)siv; + + arc4_crypt(ctx, dst, src, nbytes); + return 0; +} + +static int crypto_arc4_init(struct crypto_lskcipher *tfm) +{ + pr_warn_ratelimited("\"%s\" (%ld) uses obsolete ecb(arc4) skcipher\n", + current->comm, (unsigned long)current->pid); + + return 0; +} + +static struct lskcipher_alg arc4_alg = { + .co.base.cra_name = "arc4", + .co.base.cra_driver_name = "arc4-generic", + .co.base.cra_priority = 100, + .co.base.cra_blocksize = ARC4_BLOCK_SIZE, + .co.base.cra_ctxsize = sizeof(struct arc4_ctx), + .co.base.cra_alignmask = ARC4_ALIGN - 1, + .co.base.cra_module = THIS_MODULE, + .co.min_keysize = ARC4_MIN_KEY_SIZE, + .co.max_keysize = ARC4_MAX_KEY_SIZE, + .co.statesize = sizeof(struct arc4_ctx), + .setkey = crypto_arc4_setkey, + .encrypt = crypto_arc4_crypt, + .decrypt = crypto_arc4_crypt, + .init = crypto_arc4_init, +}; + +static int __init arc4_init(void) +{ + return crypto_register_lskcipher(&arc4_alg); +} + +static void __exit arc4_exit(void) +{ + crypto_unregister_lskcipher(&arc4_alg); +} + +module_init(arc4_init); +module_exit(arc4_exit); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("ARC4 Cipher Algorithm"); +MODULE_AUTHOR("Jon Oberheide "); +MODULE_ALIAS_CRYPTO("ecb(arc4)"); -- cgit v1.3.1