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Date: Tue, 28 Oct 2014 15:50:45 -0200
From: "Leonidas S. Barbosa" <leosilva@...ux.vnet.ibm.com>
To: linux-crypto@...r.kernel.org,
Herbert Xu <herbert@...dor.apana.org.au>,
"David S. Miller" <davem@...emloft.net>
Cc: linux-kernel@...r.kernel.org,
Marcelo Henrique Cerri <mhcerri@...ux.vnet.ibm.com>,
Fionnuala Gunter <fin@...ux.vnet.ibm.com>
Subject: [PATCH 8/9] Fixing the limit number of bytes to be processed
The previous limits were estimated locally in a single step
basead on bound values, however it was not correct since
when given certain scatterlist the function nx_build_sg_lists
was consuming more sg entries than allocated causing a
memory corruption and crashes.
e.g.: in the worst case we could have one sg entry for a single byte.
This patch fixes it modifying the logic of the bound limit
moving it to nx_sg_build_lists and set a correct sg_max limit,
adding a trim function to ensure the bound in sg_list. Also fixing
nx_build_sg_list NULL and untreated return in case of overflow.
Signed-off-by: Leonidas S. Barbosa <leosilva@...ux.vnet.ibm.com>
---
drivers/crypto/nx/nx.c | 127 ++++++++++++++++++++++++++++++++++++++++-------
drivers/crypto/nx/nx.h | 8 ++-
2 files changed, 113 insertions(+), 22 deletions(-)
diff --git a/drivers/crypto/nx/nx.c b/drivers/crypto/nx/nx.c
index 5533fe3..aa8c38d 100644
--- a/drivers/crypto/nx/nx.c
+++ b/drivers/crypto/nx/nx.c
@@ -90,7 +90,7 @@ int nx_hcall_sync(struct nx_crypto_ctx *nx_ctx,
*/
struct nx_sg *nx_build_sg_list(struct nx_sg *sg_head,
u8 *start_addr,
- unsigned int len,
+ unsigned int *len,
u32 sgmax)
{
unsigned int sg_len = 0;
@@ -106,7 +106,7 @@ struct nx_sg *nx_build_sg_list(struct nx_sg *sg_head,
else
sg_addr = __pa(sg_addr);
- end_addr = sg_addr + len;
+ end_addr = sg_addr + *len;
/* each iteration will write one struct nx_sg element and add the
* length of data described by that element to sg_len. Once @len bytes
@@ -118,7 +118,7 @@ struct nx_sg *nx_build_sg_list(struct nx_sg *sg_head,
* Also when using vmalloc'ed data, every time that a system page
* boundary is crossed the physical address needs to be re-calculated.
*/
- for (sg = sg_head; sg_len < len; sg++) {
+ for (sg = sg_head; sg_len < *len; sg++) {
u64 next_page;
sg->addr = sg_addr;
@@ -133,15 +133,17 @@ struct nx_sg *nx_build_sg_list(struct nx_sg *sg_head,
is_vmalloc_addr(start_addr + sg_len)) {
sg_addr = page_to_phys(vmalloc_to_page(
start_addr + sg_len));
- end_addr = sg_addr + len - sg_len;
+ end_addr = sg_addr + *len - sg_len;
}
if ((sg - sg_head) == sgmax) {
pr_err("nx: scatter/gather list overflow, pid: %d\n",
current->pid);
- return NULL;
+ sg++;
+ break;
}
}
+ *len = sg_len;
/* return the moved sg_head pointer */
return sg;
@@ -160,11 +162,11 @@ struct nx_sg *nx_walk_and_build(struct nx_sg *nx_dst,
unsigned int sglen,
struct scatterlist *sg_src,
unsigned int start,
- unsigned int src_len)
+ unsigned int *src_len)
{
struct scatter_walk walk;
struct nx_sg *nx_sg = nx_dst;
- unsigned int n, offset = 0, len = src_len;
+ unsigned int n, offset = 0, len = *src_len;
char *dst;
/* we need to fast forward through @start bytes first */
@@ -182,27 +184,101 @@ struct nx_sg *nx_walk_and_build(struct nx_sg *nx_dst,
* element we're currently looking at */
scatterwalk_advance(&walk, start - offset);
- while (len && nx_sg) {
+ while (len && (nx_sg - nx_dst) < sglen) {
n = scatterwalk_clamp(&walk, len);
if (!n) {
- scatterwalk_start(&walk, sg_next(walk.sg));
+ /* In cases where we have scatterlist chain scatterwalk_sg_next
+ * handles with it properly */
+ scatterwalk_start(&walk, scatterwalk_sg_next(walk.sg));
n = scatterwalk_clamp(&walk, len);
}
dst = scatterwalk_map(&walk);
- nx_sg = nx_build_sg_list(nx_sg, dst, n, sglen);
+ nx_sg = nx_build_sg_list(nx_sg, dst, &n, sglen - (nx_sg - nx_dst));
len -= n;
scatterwalk_unmap(dst);
scatterwalk_advance(&walk, n);
scatterwalk_done(&walk, SCATTERWALK_FROM_SG, len);
}
+ /* update to_process */
+ *src_len -= len;
/* return the moved destination pointer */
return nx_sg;
}
/**
+ * trim_sg_list - ensures the bound in sg list.
+ * @sg: sg list head
+ * @end: sg lisg end
+ * @delta: is the amount we need to crop in order to bound the list.
+ *
+ */
+static long int trim_sg_list(struct nx_sg *sg, struct nx_sg *end, unsigned int delta)
+{
+ while (delta && end > sg) {
+ struct nx_sg *last = end - 1;
+
+ if (last->len > delta) {
+ last->len -= delta;
+ delta = 0;
+ } else {
+ end--;
+ delta -= last->len;
+ }
+ }
+ return (sg - end) * sizeof(struct nx_sg);
+}
+
+/**
+ * nx_sha_build_sg_list - walk and build sg list to sha modes
+ * using right bounds and limits.
+ * @nx_ctx: NX crypto context for the lists we're building
+ * @nx_sg: current sg list in or out list
+ * @op_len: current op_len to be used in order to build a sg list
+ * @nbytes: number or bytes to be processed
+ * @offset: buf offset
+ * @mode: SHA256 or SHA512
+ */
+int nx_sha_build_sg_list(struct nx_crypto_ctx *nx_ctx,
+ struct nx_sg *nx_in_outsg,
+ s64 *op_len,
+ unsigned int *nbytes,
+ u8 *offset,
+ u32 mode)
+{
+ unsigned int delta = 0;
+ unsigned int total = *nbytes;
+ struct nx_sg *nx_insg = nx_in_outsg;
+ unsigned int max_sg_len;
+
+ max_sg_len = min_t(u64, nx_ctx->ap->sglen,
+ nx_driver.of.max_sg_len/sizeof(struct nx_sg));
+ max_sg_len = min_t(u64, max_sg_len,
+ nx_ctx->ap->databytelen/NX_PAGE_SIZE);
+
+ *nbytes = min_t(u64, *nbytes, nx_ctx->ap->databytelen);
+ nx_insg = nx_build_sg_list(nx_insg, offset, nbytes, max_sg_len);
+
+ switch (mode) {
+ case NX_DS_SHA256:
+ if (*nbytes < total)
+ delta = *nbytes - (*nbytes & ~(SHA256_BLOCK_SIZE - 1));
+ break;
+ case NX_DS_SHA512:
+ if (*nbytes < total)
+ delta = *nbytes - (*nbytes & ~(SHA512_BLOCK_SIZE - 1));
+ break;
+ default:
+ return -EINVAL;
+ }
+ *op_len = trim_sg_list(nx_in_outsg, nx_insg, delta);
+
+ return 0;
+}
+
+/**
* nx_build_sg_lists - walk the input scatterlists and build arrays of NX
* scatterlists based on them.
*
@@ -223,26 +299,39 @@ int nx_build_sg_lists(struct nx_crypto_ctx *nx_ctx,
struct blkcipher_desc *desc,
struct scatterlist *dst,
struct scatterlist *src,
- unsigned int nbytes,
+ unsigned int *nbytes,
unsigned int offset,
u8 *iv)
{
+ unsigned int delta = 0;
+ unsigned int total = *nbytes;
struct nx_sg *nx_insg = nx_ctx->in_sg;
struct nx_sg *nx_outsg = nx_ctx->out_sg;
+ unsigned int max_sg_len;
+
+ max_sg_len = min_t(u64, nx_ctx->ap->sglen,
+ nx_driver.of.max_sg_len/sizeof(struct nx_sg));
+ max_sg_len = min_t(u64, max_sg_len,
+ nx_ctx->ap->databytelen/NX_PAGE_SIZE);
if (iv)
memcpy(iv, desc->info, AES_BLOCK_SIZE);
- nx_insg = nx_walk_and_build(nx_insg, nx_ctx->ap->sglen, src,
- offset, nbytes);
- nx_outsg = nx_walk_and_build(nx_outsg, nx_ctx->ap->sglen, dst,
- offset, nbytes);
+ *nbytes = min_t(u64, *nbytes, nx_ctx->ap->databytelen);
+
+ nx_outsg = nx_walk_and_build(nx_outsg, max_sg_len, dst,
+ offset, nbytes);
+ nx_insg = nx_walk_and_build(nx_insg, max_sg_len, src,
+ offset, nbytes);
+
+ if (*nbytes < total)
+ delta = *nbytes - (*nbytes & ~(AES_BLOCK_SIZE - 1));
/* these lengths should be negative, which will indicate to phyp that
* the input and output parameters are scatterlists, not linear
* buffers */
- nx_ctx->op.inlen = (nx_ctx->in_sg - nx_insg) * sizeof(struct nx_sg);
- nx_ctx->op.outlen = (nx_ctx->out_sg - nx_outsg) * sizeof(struct nx_sg);
+ nx_ctx->op.inlen = trim_sg_list(nx_ctx->in_sg, nx_insg, delta);
+ nx_ctx->op.outlen = trim_sg_list(nx_ctx->out_sg, nx_outsg, delta);
return 0;
}
@@ -540,10 +629,10 @@ static int nx_crypto_ctx_init(struct nx_crypto_ctx *nx_ctx, u32 fc, u32 mode)
/* we need an extra page for csbcpb_aead for these modes */
if (mode == NX_MODE_AES_GCM || mode == NX_MODE_AES_CCM)
- nx_ctx->kmem_len = (4 * NX_PAGE_SIZE) +
+ nx_ctx->kmem_len = (5 * NX_PAGE_SIZE) +
sizeof(struct nx_csbcpb);
else
- nx_ctx->kmem_len = (3 * NX_PAGE_SIZE) +
+ nx_ctx->kmem_len = (4 * NX_PAGE_SIZE) +
sizeof(struct nx_csbcpb);
nx_ctx->kmem = kmalloc(nx_ctx->kmem_len, GFP_KERNEL);
diff --git a/drivers/crypto/nx/nx.h b/drivers/crypto/nx/nx.h
index befda07..6c9ecaa 100644
--- a/drivers/crypto/nx/nx.h
+++ b/drivers/crypto/nx/nx.h
@@ -153,13 +153,15 @@ void nx_crypto_ctx_exit(struct crypto_tfm *tfm);
void nx_ctx_init(struct nx_crypto_ctx *nx_ctx, unsigned int function);
int nx_hcall_sync(struct nx_crypto_ctx *ctx, struct vio_pfo_op *op,
u32 may_sleep);
-struct nx_sg *nx_build_sg_list(struct nx_sg *, u8 *, unsigned int, u32);
+int nx_sha_build_sg_list(struct nx_crypto_ctx *, struct nx_sg *,
+ s64 *, unsigned int *, u8 *, u32);
+struct nx_sg *nx_build_sg_list(struct nx_sg *, u8 *, unsigned int *, u32);
int nx_build_sg_lists(struct nx_crypto_ctx *, struct blkcipher_desc *,
- struct scatterlist *, struct scatterlist *, unsigned int,
+ struct scatterlist *, struct scatterlist *, unsigned int *,
unsigned int, u8 *);
struct nx_sg *nx_walk_and_build(struct nx_sg *, unsigned int,
struct scatterlist *, unsigned int,
- unsigned int);
+ unsigned int *);
#ifdef CONFIG_DEBUG_FS
#define NX_DEBUGFS_INIT(drv) nx_debugfs_init(drv)
--
1.7.1
--
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