diff mbox series

[4.4.y] crypto: vmx - Fix sleep-in-atomic bugs

Message ID 20180910074204.10812-1-omosnace@redhat.com (mailing list archive)
State Not Applicable
Headers show
Series [4.4.y] crypto: vmx - Fix sleep-in-atomic bugs | expand

Commit Message

Ondrej Mosnacek Sept. 10, 2018, 7:42 a.m. UTC
commit 0522236d4f9c5ab2e79889cb020d1acbe5da416e upstream.

Conflicts:
  drivers/crypto/vmx/
    aes_cbc.c - adapted enable/disable calls to v4.4 state
    aes_xts.c - did not exist yet in v4.4

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>
---
 drivers/crypto/vmx/aes_cbc.c | 30 ++++++++++++++----------------
 1 file changed, 14 insertions(+), 16 deletions(-)

Comments

Ondrej Mosnacek Sept. 10, 2018, 7:47 a.m. UTC | #1
On Mon, Sep 10, 2018 at 9:42 AM Ondrej Mosnacek <omosnace@redhat.com> wrote:
> commit 0522236d4f9c5ab2e79889cb020d1acbe5da416e upstream.
>
> Conflicts:
>   drivers/crypto/vmx/
>     aes_cbc.c - adapted enable/disable calls to v4.4 state
>     aes_xts.c - did not exist yet in v4.4
>
> 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>

Whoops, sorry about that last Signed-off-by, I cherry-picked from
another stable commit and forgot to edit it out...

> ---
>  drivers/crypto/vmx/aes_cbc.c | 30 ++++++++++++++----------------
>  1 file changed, 14 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/crypto/vmx/aes_cbc.c b/drivers/crypto/vmx/aes_cbc.c
> index 9506e8693c81..d8ef1147b344 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_altivec();
> -               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();
> +                       enable_kernel_altivec();
>                         aes_p8_cbc_encrypt(walk.src.virt.addr,
>                                            walk.dst.virt.addr,
>                                            nbytes & AES_BLOCK_MASK,
>                                            &ctx->enc_key, walk.iv, 1);
> +                       pagefault_enable();
> +                       preempt_enable();
> +
>                         nbytes &= AES_BLOCK_SIZE - 1;
>                         ret = blkcipher_walk_done(desc, &walk, nbytes);
>                 }
> -
> -               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_altivec();
> -               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();
> +                       enable_kernel_altivec();
>                         aes_p8_cbc_encrypt(walk.src.virt.addr,
>                                            walk.dst.virt.addr,
>                                            nbytes & AES_BLOCK_MASK,
>                                            &ctx->dec_key, walk.iv, 0);
> +                       pagefault_enable();
> +                       preempt_enable();
> +
>                         nbytes &= AES_BLOCK_SIZE - 1;
>                         ret = blkcipher_walk_done(desc, &walk, nbytes);
>                 }
> -
> -               pagefault_enable();
> -               preempt_enable();
>         }
>
>         return ret;
> --
> 2.17.1
>
Greg KH Sept. 17, 2018, 11:47 a.m. UTC | #2
On Mon, Sep 10, 2018 at 09:42:04AM +0200, Ondrej Mosnacek wrote:
> commit 0522236d4f9c5ab2e79889cb020d1acbe5da416e upstream.
> 
> Conflicts:
>   drivers/crypto/vmx/
>     aes_cbc.c - adapted enable/disable calls to v4.4 state
>     aes_xts.c - did not exist yet in v4.4

We don't need these lines here...  I'll go hand edit it out...
Greg KH Sept. 17, 2018, 11:47 a.m. UTC | #3
On Mon, Sep 10, 2018 at 09:42:04AM +0200, Ondrej Mosnacek wrote:
> commit 0522236d4f9c5ab2e79889cb020d1acbe5da416e upstream.
> 
> Conflicts:
>   drivers/crypto/vmx/
>     aes_cbc.c - adapted enable/disable calls to v4.4 state
>     aes_xts.c - did not exist yet in v4.4

Now applied, thanks.

greg k-h
diff mbox series

Patch

diff --git a/drivers/crypto/vmx/aes_cbc.c b/drivers/crypto/vmx/aes_cbc.c
index 9506e8693c81..d8ef1147b344 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_altivec();
-		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();
+			enable_kernel_altivec();
 			aes_p8_cbc_encrypt(walk.src.virt.addr,
 					   walk.dst.virt.addr,
 					   nbytes & AES_BLOCK_MASK,
 					   &ctx->enc_key, walk.iv, 1);
+			pagefault_enable();
+			preempt_enable();
+
 			nbytes &= AES_BLOCK_SIZE - 1;
 			ret = blkcipher_walk_done(desc, &walk, nbytes);
 		}
-
-		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_altivec();
-		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();
+			enable_kernel_altivec();
 			aes_p8_cbc_encrypt(walk.src.virt.addr,
 					   walk.dst.virt.addr,
 					   nbytes & AES_BLOCK_MASK,
 					   &ctx->dec_key, walk.iv, 0);
+			pagefault_enable();
+			preempt_enable();
+
 			nbytes &= AES_BLOCK_SIZE - 1;
 			ret = blkcipher_walk_done(desc, &walk, nbytes);
 		}
-
-		pagefault_enable();
-		preempt_enable();
 	}
 
 	return ret;