releases/4.19.49/s390-crypto-fix-possible-sleep-during-spinlock-aquired.patch

   1 From 1c2c7029c008922d4d48902cc386250502e73d51 Mon Sep 17 00:00:00 2001
   2 From: Harald Freudenberger <freude@linux.ibm.com>
   3 Date: Mon, 27 May 2019 15:24:20 +0200
   4 Subject: s390/crypto: fix possible sleep during spinlock aquired
   5
   6 From: Harald Freudenberger <freude@linux.ibm.com>
   7
   8 commit 1c2c7029c008922d4d48902cc386250502e73d51 upstream.
   9
  10 This patch fixes a complain about possible sleep during
  11 spinlock aquired
  12 "BUG: sleeping function called from invalid context at
  13 include/crypto/algapi.h:426"
  14 for the ctr(aes) and ctr(des) s390 specific ciphers.
  15
  16 Instead of using a spinlock this patch introduces a mutex
  17 which is save to be held in sleeping context. Please note
  18 a deadlock is not possible as mutex_trylock() is used.
  19
  20 Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
  21 Reported-by: Julian Wiedmann <jwi@linux.ibm.com>
  22 Cc: stable@vger.kernel.org
  23 Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
  24 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  25
  26 ---
  27  arch/s390/crypto/aes_s390.c |    8 ++++----
  28  arch/s390/crypto/des_s390.c |    7 ++++---
  29  2 files changed, 8 insertions(+), 7 deletions(-)
  30
  31 --- a/arch/s390/crypto/aes_s390.c
  32 +++ b/arch/s390/crypto/aes_s390.c
  33 @@ -27,14 +27,14 @@
  34  #include <linux/module.h>
  35  #include <linux/cpufeature.h>
  36  #include <linux/init.h>
  37 -#include <linux/spinlock.h>
  38 +#include <linux/mutex.h>
  39  #include <linux/fips.h>
  40  #include <linux/string.h>
  41  #include <crypto/xts.h>
  42  #include <asm/cpacf.h>
  43
  44  static u8 *ctrblk;
  45 -static DEFINE_SPINLOCK(ctrblk_lock);
  46 +static DEFINE_MUTEX(ctrblk_lock);
  47
  48  static cpacf_mask_t km_functions, kmc_functions, kmctr_functions,
  49                     kma_functions;
  50 @@ -698,7 +698,7 @@ static int ctr_aes_crypt(struct blkciphe
  51         unsigned int n, nbytes;
  52         int ret, locked;
  53
  54 -       locked = spin_trylock(&ctrblk_lock);
  55 +       locked = mutex_trylock(&ctrblk_lock);
  56
  57         ret = blkcipher_walk_virt_block(desc, walk, AES_BLOCK_SIZE);
  58         while ((nbytes = walk->nbytes) >= AES_BLOCK_SIZE) {
  59 @@ -716,7 +716,7 @@ static int ctr_aes_crypt(struct blkciphe
  60                 ret = blkcipher_walk_done(desc, walk, nbytes - n);
  61         }
  62         if (locked)
  63 -               spin_unlock(&ctrblk_lock);
  64 +               mutex_unlock(&ctrblk_lock);
  65         /*
  66          * final block may be < AES_BLOCK_SIZE, copy only nbytes
  67          */
  68 --- a/arch/s390/crypto/des_s390.c
  69 +++ b/arch/s390/crypto/des_s390.c
  70 @@ -14,6 +14,7 @@
  71  #include <linux/cpufeature.h>
  72  #include <linux/crypto.h>
  73  #include <linux/fips.h>
  74 +#include <linux/mutex.h>
  75  #include <crypto/algapi.h>
  76  #include <crypto/des.h>
  77  #include <asm/cpacf.h>
  78 @@ -21,7 +22,7 @@
  79  #define DES3_KEY_SIZE  (3 * DES_KEY_SIZE)
  80
  81  static u8 *ctrblk;
  82 -static DEFINE_SPINLOCK(ctrblk_lock);
  83 +static DEFINE_MUTEX(ctrblk_lock);
  84
  85  static cpacf_mask_t km_functions, kmc_functions, kmctr_functions;
  86
  87 @@ -387,7 +388,7 @@ static int ctr_desall_crypt(struct blkci
  88         unsigned int n, nbytes;
  89         int ret, locked;
  90
  91 -       locked = spin_trylock(&ctrblk_lock);
  92 +       locked = mutex_trylock(&ctrblk_lock);
  93
  94         ret = blkcipher_walk_virt_block(desc, walk, DES_BLOCK_SIZE);
  95         while ((nbytes = walk->nbytes) >= DES_BLOCK_SIZE) {
  96 @@ -404,7 +405,7 @@ static int ctr_desall_crypt(struct blkci
  97                 ret = blkcipher_walk_done(desc, walk, nbytes - n);
  98         }
  99         if (locked)
 100 -               spin_unlock(&ctrblk_lock);
 101 +               mutex_unlock(&ctrblk_lock);
 102         /* final block may be < DES_BLOCK_SIZE, copy only nbytes */
 103         if (nbytes) {
 104                 cpacf_kmctr(fc, ctx->key, buf, walk->src.virt.addr,