| Message ID | 20180822062631.5664-1-omosnace@redhat.com (mailing list archive) |
|---|---|
| State | Accepted |
| Delegated to: | Herbert Xu |
| Headers | show |
| Series | [v2] crypto: vmx - Fix sleep-in-atomic bugs | expand |
That looks good to me. Maybe Paulo can help testing it.
On 2018-08-22 21:04, Marcelo Henrique Cerri wrote: > That looks good to me. Maybe Paulo can help testing it. > > -- > Regards, > Marcelo > > On Wed, Aug 22, 2018 at 08:26:31AM +0200, Ondrej Mosnacek wrote: >> 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> >> --- >> Still untested, please test and review if possible. >> >> Changes in v2: >> - fix leaving preemtption, etc. disabled when leaving the function >> (I switched to the more obvious and less efficient variant for the >> sake of clarity.) >> >> drivers/crypto/vmx/aes_cbc.c | 30 ++++++++++++++---------------- >> drivers/crypto/vmx/aes_xts.c | 21 ++++++++++++++------- >> 2 files changed, 28 insertions(+), 23 deletions(-) >> >> diff --git a/drivers/crypto/vmx/aes_cbc.c >> b/drivers/crypto/vmx/aes_cbc.c >> index 5285ece4f33a..b71895871be3 100644 >> --- a/drivers/crypto/vmx/aes_cbc.c >> +++ b/drivers/crypto/vmx/aes_cbc.c >> @@ -107,24 +107,23 @@ static int p8_aes_cbc_encrypt(struct >> blkcipher_desc *desc, >> ret = crypto_skcipher_encrypt(req); >> skcipher_request_zero(req); >> } 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; >> @@ -147,24 +146,23 @@ static int p8_aes_cbc_decrypt(struct >> blkcipher_desc *desc, >> ret = crypto_skcipher_decrypt(req); >> skcipher_request_zero(req); >> } 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 8bd9aff0f55f..e9954a7d4694 100644 >> --- a/drivers/crypto/vmx/aes_xts.c >> +++ b/drivers/crypto/vmx/aes_xts.c >> @@ -116,32 +116,39 @@ static int p8_aes_xts_crypt(struct >> blkcipher_desc *desc, >> ret = enc? crypto_skcipher_encrypt(req) : >> crypto_skcipher_decrypt(req); >> skcipher_request_zero(req); >> } 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; >> } >> -- >> 2.17.1 >> Sure thing. I'll test it later today. Thanks Ondrej for the fix.
On 2018-08-23 17:34, Paulo Flabiano Smorigo wrote: > On 2018-08-22 21:04, Marcelo Henrique Cerri wrote: >> That looks good to me. Maybe Paulo can help testing it. >> >> -- >> Regards, >> Marcelo >> >> On Wed, Aug 22, 2018 at 08:26:31AM +0200, Ondrej Mosnacek wrote: >>> 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> >>> --- >>> Still untested, please test and review if possible. >>> >>> Changes in v2: >>> - fix leaving preemtption, etc. disabled when leaving the function >>> (I switched to the more obvious and less efficient variant for the >>> sake of clarity.) >>> >>> drivers/crypto/vmx/aes_cbc.c | 30 ++++++++++++++---------------- >>> drivers/crypto/vmx/aes_xts.c | 21 ++++++++++++++------- >>> 2 files changed, 28 insertions(+), 23 deletions(-) >>> >>> diff --git a/drivers/crypto/vmx/aes_cbc.c >>> b/drivers/crypto/vmx/aes_cbc.c >>> index 5285ece4f33a..b71895871be3 100644 >>> --- a/drivers/crypto/vmx/aes_cbc.c >>> +++ b/drivers/crypto/vmx/aes_cbc.c >>> @@ -107,24 +107,23 @@ static int p8_aes_cbc_encrypt(struct >>> blkcipher_desc *desc, >>> ret = crypto_skcipher_encrypt(req); >>> skcipher_request_zero(req); >>> } 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; >>> @@ -147,24 +146,23 @@ static int p8_aes_cbc_decrypt(struct >>> blkcipher_desc *desc, >>> ret = crypto_skcipher_decrypt(req); >>> skcipher_request_zero(req); >>> } 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 8bd9aff0f55f..e9954a7d4694 100644 >>> --- a/drivers/crypto/vmx/aes_xts.c >>> +++ b/drivers/crypto/vmx/aes_xts.c >>> @@ -116,32 +116,39 @@ static int p8_aes_xts_crypt(struct >>> blkcipher_desc *desc, >>> ret = enc? crypto_skcipher_encrypt(req) : >>> crypto_skcipher_decrypt(req); >>> skcipher_request_zero(req); >>> } 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; >>> } >>> -- >>> 2.17.1 >>> > > Sure thing. I'll test it later today. Thanks Ondrej for the fix. Looks good to me. I made some tests here and no problem was found.
On Fri, Aug 24, 2018 at 9:39 PM Paulo Flabiano Smorigo <pfsmorigo@linux.vnet.ibm.com> wrote: > On 2018-08-23 17:34, Paulo Flabiano Smorigo wrote: > > On 2018-08-22 21:04, Marcelo Henrique Cerri wrote: > >> That looks good to me. Maybe Paulo can help testing it. > >> > >> -- > >> Regards, > >> Marcelo > >> > >> On Wed, Aug 22, 2018 at 08:26:31AM +0200, Ondrej Mosnacek wrote: > >>> 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> > >>> --- > >>> Still untested, please test and review if possible. > >>> > >>> Changes in v2: > >>> - fix leaving preemtption, etc. disabled when leaving the function > >>> (I switched to the more obvious and less efficient variant for the > >>> sake of clarity.) > >>> > >>> drivers/crypto/vmx/aes_cbc.c | 30 ++++++++++++++---------------- > >>> drivers/crypto/vmx/aes_xts.c | 21 ++++++++++++++------- > >>> 2 files changed, 28 insertions(+), 23 deletions(-) > >>> > >>> diff --git a/drivers/crypto/vmx/aes_cbc.c > >>> b/drivers/crypto/vmx/aes_cbc.c > >>> index 5285ece4f33a..b71895871be3 100644 > >>> --- a/drivers/crypto/vmx/aes_cbc.c > >>> +++ b/drivers/crypto/vmx/aes_cbc.c > >>> @@ -107,24 +107,23 @@ static int p8_aes_cbc_encrypt(struct > >>> blkcipher_desc *desc, > >>> ret = crypto_skcipher_encrypt(req); > >>> skcipher_request_zero(req); > >>> } 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; > >>> @@ -147,24 +146,23 @@ static int p8_aes_cbc_decrypt(struct > >>> blkcipher_desc *desc, > >>> ret = crypto_skcipher_decrypt(req); > >>> skcipher_request_zero(req); > >>> } 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 8bd9aff0f55f..e9954a7d4694 100644 > >>> --- a/drivers/crypto/vmx/aes_xts.c > >>> +++ b/drivers/crypto/vmx/aes_xts.c > >>> @@ -116,32 +116,39 @@ static int p8_aes_xts_crypt(struct > >>> blkcipher_desc *desc, > >>> ret = enc? crypto_skcipher_encrypt(req) : > >>> crypto_skcipher_decrypt(req); > >>> skcipher_request_zero(req); > >>> } 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; > >>> } > >>> -- > >>> 2.17.1 > >>> > > > > Sure thing. I'll test it later today. Thanks Ondrej for the fix. > > Looks good to me. I made some tests here and no problem was found. Great, thanks!
On Wed, Aug 22, 2018 at 08:26:31AM +0200, Ondrej Mosnacek wrote: > 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> Patch applied. Thanks.
diff --git a/drivers/crypto/vmx/aes_cbc.c b/drivers/crypto/vmx/aes_cbc.c index 5285ece4f33a..b71895871be3 100644 --- a/drivers/crypto/vmx/aes_cbc.c +++ b/drivers/crypto/vmx/aes_cbc.c @@ -107,24 +107,23 @@ static int p8_aes_cbc_encrypt(struct blkcipher_desc *desc, ret = crypto_skcipher_encrypt(req); skcipher_request_zero(req); } 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; @@ -147,24 +146,23 @@ static int p8_aes_cbc_decrypt(struct blkcipher_desc *desc, ret = crypto_skcipher_decrypt(req); skcipher_request_zero(req); } 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 8bd9aff0f55f..e9954a7d4694 100644 --- a/drivers/crypto/vmx/aes_xts.c +++ b/drivers/crypto/vmx/aes_xts.c @@ -116,32 +116,39 @@ static int p8_aes_xts_crypt(struct blkcipher_desc *desc, ret = enc? crypto_skcipher_encrypt(req) : crypto_skcipher_decrypt(req); skcipher_request_zero(req); } 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; }
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> --- Still untested, please test and review if possible. Changes in v2: - fix leaving preemtption, etc. disabled when leaving the function (I switched to the more obvious and less efficient variant for the sake of clarity.) drivers/crypto/vmx/aes_cbc.c | 30 ++++++++++++++---------------- drivers/crypto/vmx/aes_xts.c | 21 ++++++++++++++------- 2 files changed, 28 insertions(+), 23 deletions(-)