Skip to contentSkip to conversation

FAILED: patch "[PATCH] crypto: virtio: Fix src/dst scatterlist calculation in" failed to apply to 5.4-stable tree

PATCH [email protected] 2 participants 2 messages Jun 15, 2020 – Jun 16, 2020

Subsystems (4)
lore
Share & tools
lore

[email protected]

author maintainer
#0 lore raw

The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From b02989f37fc5e865ceeee9070907e4493b3a21e2 Mon Sep 17 00:00:00 2001
From: "Longpeng(Mike)" <[email protected]>
Date: Tue, 2 Jun 2020 15:04:59 +0800
Subject: [PATCH] crypto: virtio: Fix src/dst scatterlist calculation in
__virtio_crypto_skcipher_do_req()

The system will crash when the users insmod crypto/tcrypt.ko with mode=38 ( testing "cts(cbc(aes))" ).

Usually the next entry of one sg will be @sg@ + 1, but if this sg element is part of a chained scatterlist, it could jump to the start of a new scatterlist array. Fix it by sg_next() on calculation of src/dst scatterlist.

drivers/crypto/virtio/virtio_crypto_algs.c +10 -5
index fd045e64972a..5f8243563009 100644
@@ -350,13 +350,18 @@ __virtio_crypto_skcipher_do_req(struct virtio_crypto_sym_request *vc_sym_req,
 	int err;
 	unsigned long flags;
 	struct scatterlist outhdr, iv_sg, status_sg, **sgs;
-	int i;
 	u64 dst_len;
 	unsigned int num_out = 0, num_in = 0;
 	int sg_total;
 	uint8_t *iv;
+	struct scatterlist *sg;
 
 	src_nents = sg_nents_for_len(req->src, req->cryptlen);
+	if (src_nents < 0) {
+		pr_err("Invalid number of src SG.\n");
+		return src_nents;
+	}
+
 	dst_nents = sg_nents(req->dst);
 
 	pr_debug("virtio_crypto: Number of sgs (src_nents: %d, dst_nents: %d)\n",
@@ -442,12 +447,12 @@ __virtio_crypto_skcipher_do_req(struct virtio_crypto_sym_request *vc_sym_req,
 	vc_sym_req->iv = iv;
 
 	/* Source data */
-	for (i = 0; i < src_nents; i++)
-		sgs[num_out++] = &req->src[i];
+	for (sg = req->src; src_nents; sg = sg_next(sg), src_nents--)
+		sgs[num_out++] = sg;
 
 	/* Destination data */
-	for (i = 0; i < dst_nents; i++)
-		sgs[num_out + num_in++] = &req->dst[i];
+	for (sg = req->dst; sg; sg = sg_next(sg))
+		sgs[num_out + num_in++] = sg;
 
 	/* Status */
 	sg_init_one(&status_sg, &vc_req->status, sizeof(vc_req->status));
maintainer
#1 lore raw
Quoted 26 lines · On Mon, Jun 15, 2020 at 10:19:45PM +0200, [email protected] wrote:

The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From b02989f37fc5e865ceeee9070907e4493b3a21e2 Mon Sep 17 00:00:00 2001
From: "Longpeng(Mike)" <[email protected]>
Date: Tue, 2 Jun 2020 15:04:59 +0800
Subject: [PATCH] crypto: virtio: Fix src/dst scatterlist calculation in __virtio_crypto_skcipher_do_req()

The system will crash when the users insmod crypto/tcrypt.ko with mode=38 ( testing "cts(cbc(aes))" ).

Usually the next entry of one sg will be @sg@ + 1, but if this sg element is part of a chained scatterlist, it could jump to the start of a new scatterlist array. Fix it by sg_next() on calculation of src/dst scatterlist.

Quoted 14 lines

I've worked around missing eee1d6fca0a0 ("crypto: virtio - switch to skcipher API") and queued it for 5.4, 4.19, and 4.14.

Signature · 2 lines
Thanks,
Sasha