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authorOndrej Mosnacek <omosnace@redhat.com>2018-08-22 08:26:31 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-09-09 20:01:25 +0200
commit4a219e41a9dbf14a17d0056e7a1a148196117ba5 (patch)
tree8e0a02c577e2cc045d8788eaa9c8a7f7fa5586fd /drivers/crypto
parente0ec112e7eb158de714f37a444a4eb861f839c10 (diff)
crypto: vmx - Fix sleep-in-atomic bugs
commit 0522236d4f9c5ab2e79889cb020d1acbe5da416e upstream. This patch fixes sleep-in-atomic bugs in AES-CBC and AES-XTS VMX implementations. The problem is that the blkcipher_* functions should not be called in atomic context. The bugs can be reproduced via the AF_ALG interface by trying to encrypt/decrypt sufficiently large buffers (at least 64 KiB) using the VMX implementations of 'cbc(aes)' or 'xts(aes)'. Such operations then trigger BUG in crypto_yield(): [ 891.863680] BUG: sleeping function called from invalid context at include/crypto/algapi.h:424 [ 891.864622] in_atomic(): 1, irqs_disabled(): 0, pid: 12347, name: kcapi-enc [ 891.864739] 1 lock held by kcapi-enc/12347: [ 891.864811] #0: 00000000f5d42c46 (sk_lock-AF_ALG){+.+.}, at: skcipher_recvmsg+0x50/0x530 [ 891.865076] CPU: 5 PID: 12347 Comm: kcapi-enc Not tainted 4.19.0-0.rc0.git3.1.fc30.ppc64le #1 [ 891.865251] Call Trace: [ 891.865340] [c0000003387578c0] [c000000000d67ea4] dump_stack+0xe8/0x164 (unreliable) [ 891.865511] [c000000338757910] [c000000000172a58] ___might_sleep+0x2f8/0x310 [ 891.865679] [c000000338757990] [c0000000006bff74] blkcipher_walk_done+0x374/0x4a0 [ 891.865825] [c0000003387579e0] [d000000007e73e70] p8_aes_cbc_encrypt+0x1c8/0x260 [vmx_crypto] [ 891.865993] [c000000338757ad0] [c0000000006c0ee0] skcipher_encrypt_blkcipher+0x60/0x80 [ 891.866128] [c000000338757b10] [c0000000006ec504] skcipher_recvmsg+0x424/0x530 [ 891.866283] [c000000338757bd0] [c000000000b00654] sock_recvmsg+0x74/0xa0 [ 891.866403] [c000000338757c10] [c000000000b00f64] ___sys_recvmsg+0xf4/0x2f0 [ 891.866515] [c000000338757d90] [c000000000b02bb8] __sys_recvmsg+0x68/0xe0 [ 891.866631] [c000000338757e30] [c00000000000bbe4] system_call+0x5c/0x70 Fixes: 8c755ace357c ("crypto: vmx - Adding CBC routines for VMX module") Fixes: c07f5d3da643 ("crypto: vmx - Adding support for XTS") Cc: stable@vger.kernel.org Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/crypto')
-rw-r--r--drivers/crypto/vmx/aes_cbc.c30
-rw-r--r--drivers/crypto/vmx/aes_xts.c21
2 files changed, 28 insertions, 23 deletions
diff --git a/drivers/crypto/vmx/aes_cbc.c b/drivers/crypto/vmx/aes_cbc.c
index 46131701c378..92e116365272 100644
--- a/drivers/crypto/vmx/aes_cbc.c
+++ b/drivers/crypto/vmx/aes_cbc.c
@@ -111,24 +111,23 @@ static int p8_aes_cbc_encrypt(struct blkcipher_desc *desc,
ret = crypto_blkcipher_encrypt(&fallback_desc, dst, src,
nbytes);
} else {
- preempt_disable();
- pagefault_disable();
- enable_kernel_vsx();
-
blkcipher_walk_init(&walk, dst, src, nbytes);
ret = blkcipher_walk_virt(desc, &walk);
while ((nbytes = walk.nbytes)) {
+ preempt_disable();
+ pagefault_disable();
+ enable_kernel_vsx();
aes_p8_cbc_encrypt(walk.src.virt.addr,
walk.dst.virt.addr,
nbytes & AES_BLOCK_MASK,
&ctx->enc_key, walk.iv, 1);
+ disable_kernel_vsx();
+ pagefault_enable();
+ preempt_enable();
+
nbytes &= AES_BLOCK_SIZE - 1;
ret = blkcipher_walk_done(desc, &walk, nbytes);
}
-
- disable_kernel_vsx();
- pagefault_enable();
- preempt_enable();
}
return ret;
@@ -152,24 +151,23 @@ static int p8_aes_cbc_decrypt(struct blkcipher_desc *desc,
ret = crypto_blkcipher_decrypt(&fallback_desc, dst, src,
nbytes);
} else {
- preempt_disable();
- pagefault_disable();
- enable_kernel_vsx();
-
blkcipher_walk_init(&walk, dst, src, nbytes);
ret = blkcipher_walk_virt(desc, &walk);
while ((nbytes = walk.nbytes)) {
+ preempt_disable();
+ pagefault_disable();
+ enable_kernel_vsx();
aes_p8_cbc_encrypt(walk.src.virt.addr,
walk.dst.virt.addr,
nbytes & AES_BLOCK_MASK,
&ctx->dec_key, walk.iv, 0);
+ disable_kernel_vsx();
+ pagefault_enable();
+ preempt_enable();
+
nbytes &= AES_BLOCK_SIZE - 1;
ret = blkcipher_walk_done(desc, &walk, nbytes);
}
-
- disable_kernel_vsx();
- pagefault_enable();
- preempt_enable();
}
return ret;
diff --git a/drivers/crypto/vmx/aes_xts.c b/drivers/crypto/vmx/aes_xts.c
index 24353ec336c5..52e7ae05ae1f 100644
--- a/drivers/crypto/vmx/aes_xts.c
+++ b/drivers/crypto/vmx/aes_xts.c
@@ -123,32 +123,39 @@ static int p8_aes_xts_crypt(struct blkcipher_desc *desc,
ret = enc ? crypto_blkcipher_encrypt(&fallback_desc, dst, src, nbytes) :
crypto_blkcipher_decrypt(&fallback_desc, dst, src, nbytes);
} else {
+ blkcipher_walk_init(&walk, dst, src, nbytes);
+
+ ret = blkcipher_walk_virt(desc, &walk);
+
preempt_disable();
pagefault_disable();
enable_kernel_vsx();
- blkcipher_walk_init(&walk, dst, src, nbytes);
-
- ret = blkcipher_walk_virt(desc, &walk);
iv = walk.iv;
memset(tweak, 0, AES_BLOCK_SIZE);
aes_p8_encrypt(iv, tweak, &ctx->tweak_key);
+ disable_kernel_vsx();
+ pagefault_enable();
+ preempt_enable();
+
while ((nbytes = walk.nbytes)) {
+ preempt_disable();
+ pagefault_disable();
+ enable_kernel_vsx();
if (enc)
aes_p8_xts_encrypt(walk.src.virt.addr, walk.dst.virt.addr,
nbytes & AES_BLOCK_MASK, &ctx->enc_key, NULL, tweak);
else
aes_p8_xts_decrypt(walk.src.virt.addr, walk.dst.virt.addr,
nbytes & AES_BLOCK_MASK, &ctx->dec_key, NULL, tweak);
+ disable_kernel_vsx();
+ pagefault_enable();
+ preempt_enable();
nbytes &= AES_BLOCK_SIZE - 1;
ret = blkcipher_walk_done(desc, &walk, nbytes);
}
-
- disable_kernel_vsx();
- pagefault_enable();
- preempt_enable();
}
return ret;
}