This is a note to let you know that I've just added the patch titled
crypto: af_alg - Fix race around ctx->rcvused by making it atomic_t
to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
crypto-af_alg-fix-race-around-ctx-rcvused-by-making-it-atomic_t.patch
and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Wed Feb 28 16:23:28 CET 2018
From: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Date: Tue, 19 Dec 2017 10:27:24 +0000
Subject: crypto: af_alg - Fix race around ctx->rcvused by making it atomic_t
From: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
[ Upstream commit af955bf15d2c27496b0269b1f05c26f758c68314 ]
This variable was increased and decreased without any protection.
Result was an occasional misscount and negative wrap around resulting
in false resource allocation failures.
Fixes: 7d2c3f54e6f6 ("crypto: af_alg - remove locking in async callback")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Reviewed-by: Stephan Mueller <smueller@xxxxxxxxxx>
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
crypto/af_alg.c | 4 ++--
crypto/algif_aead.c | 2 +-
crypto/algif_skcipher.c | 2 +-
include/crypto/if_alg.h | 5 +++--
4 files changed, 7 insertions(+), 6 deletions(-)
--- a/crypto/af_alg.c
+++ b/crypto/af_alg.c
@@ -693,7 +693,7 @@ void af_alg_free_areq_sgls(struct af_alg
unsigned int i;
list_for_each_entry_safe(rsgl, tmp, &areq->rsgl_list, list) {
- ctx->rcvused -= rsgl->sg_num_bytes;
+ atomic_sub(rsgl->sg_num_bytes, &ctx->rcvused);
af_alg_free_sg(&rsgl->sgl);
list_del(&rsgl->list);
if (rsgl != &areq->first_rsgl)
@@ -1192,7 +1192,7 @@ int af_alg_get_rsgl(struct sock *sk, str
areq->last_rsgl = rsgl;
len += err;
- ctx->rcvused += err;
+ atomic_add(err, &ctx->rcvused);
rsgl->sg_num_bytes = err;
iov_iter_advance(&msg->msg_iter, err);
}
--- a/crypto/algif_aead.c
+++ b/crypto/algif_aead.c
@@ -571,7 +571,7 @@ static int aead_accept_parent_nokey(void
INIT_LIST_HEAD(&ctx->tsgl_list);
ctx->len = len;
ctx->used = 0;
- ctx->rcvused = 0;
+ atomic_set(&ctx->rcvused, 0);
ctx->more = 0;
ctx->merge = 0;
ctx->enc = 0;
--- a/crypto/algif_skcipher.c
+++ b/crypto/algif_skcipher.c
@@ -391,7 +391,7 @@ static int skcipher_accept_parent_nokey(
INIT_LIST_HEAD(&ctx->tsgl_list);
ctx->len = len;
ctx->used = 0;
- ctx->rcvused = 0;
+ atomic_set(&ctx->rcvused, 0);
ctx->more = 0;
ctx->merge = 0;
ctx->enc = 0;
--- a/include/crypto/if_alg.h
+++ b/include/crypto/if_alg.h
@@ -18,6 +18,7 @@
#include <linux/if_alg.h>
#include <linux/scatterlist.h>
#include <linux/types.h>
+#include <linux/atomic.h>
#include <net/sock.h>
#include <crypto/aead.h>
@@ -155,7 +156,7 @@ struct af_alg_ctx {
struct af_alg_completion completion;
size_t used;
- size_t rcvused;
+ atomic_t rcvused;
bool more;
bool merge;
@@ -228,7 +229,7 @@ static inline int af_alg_rcvbuf(struct s
struct af_alg_ctx *ctx = ask->private;
return max_t(int, max_t(int, sk->sk_rcvbuf & PAGE_MASK, PAGE_SIZE) -
- ctx->rcvused, 0);
+ atomic_read(&ctx->rcvused), 0);
}
/**
Patches currently in stable-queue which might be from Jonathan.Cameron@xxxxxxxxxx are
queue-4.14/crypto-af_alg-fix-race-around-ctx-rcvused-by-making-it-atomic_t.patch