KMSAN: uninit-value in aes_encrypt (2)

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 3c8ca708 test_kmsan.c: fix SPDX comment
git tree: https://github.com/google/kmsan.git master
console output: https://syzkaller.appspot.com/x/log.txt?x=14129497600000
kernel config: https://syzkaller.appspot.com/x/.config?x=c07a3d4f8a59e198
dashboard link: https://syzkaller.appspot.com/bug?extid=9e3b178624a8a2f8fa28
compiler: clang version 9.0.0 (/home/glider/llvm/clang
80fee25776c2fb61e74c1ecb1a523375c2500b69)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=11331128e00000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=140b47ef600000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+9e3b17...@syzkaller.appspotmail.com

IPv6: ADDRCONF(NETDEV_CHANGE): hsr0: link becomes ready
8021q: adding VLAN 0 to HW filter on device batadv0
=====================================================
BUG: KMSAN: uninit-value in subshift lib/crypto/aes.c:149 [inline]
BUG: KMSAN: uninit-value in aes_encrypt+0x12d5/0x1bd0 lib/crypto/aes.c:282
CPU: 0 PID: 12200 Comm: syz-executor134 Not tainted 5.4.0-rc3+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x191/0x1f0 lib/dump_stack.c:113
kmsan_report+0x14a/0x2f0 mm/kmsan/kmsan_report.c:110
__msan_warning+0x73/0xf0 mm/kmsan/kmsan_instr.c:245
subshift lib/crypto/aes.c:149 [inline]
aes_encrypt+0x12d5/0x1bd0 lib/crypto/aes.c:282
aesti_encrypt+0xe8/0x130 crypto/aes_ti.c:31
crypto_cipher_encrypt_one include/linux/crypto.h:1763 [inline]
crypto_cbcmac_digest_update+0x3cf/0x550 crypto/ccm.c:871
crypto_shash_update crypto/shash.c:107 [inline]
shash_ahash_finup+0x659/0xb20 crypto/shash.c:276
shash_async_finup+0xbb/0x110 crypto/shash.c:291
crypto_ahash_op+0x1cd/0x6e0 crypto/ahash.c:368
crypto_ahash_finup+0x8c/0xb0 crypto/ahash.c:393
crypto_ccm_auth+0x14b2/0x1570 crypto/ccm.c:230
crypto_ccm_encrypt+0x283/0x840 crypto/ccm.c:309
crypto_aead_encrypt+0xf2/0x180 crypto/aead.c:99
tls_do_encryption net/tls/tls_sw.c:521 [inline]
tls_push_record+0x341e/0x4e50 net/tls/tls_sw.c:730
bpf_exec_tx_verdict+0x1454/0x1c80 net/tls/tls_sw.c:770
tls_sw_sendmsg+0x158d/0x2710 net/tls/tls_sw.c:1033
inet6_sendmsg+0x2d8/0x2e0 net/ipv6/af_inet6.c:576
sock_sendmsg_nosec net/socket.c:637 [inline]
sock_sendmsg net/socket.c:657 [inline]
__sys_sendto+0x8fc/0xc70 net/socket.c:1952
__do_sys_sendto net/socket.c:1964 [inline]
__se_sys_sendto+0x107/0x130 net/socket.c:1960
__x64_sys_sendto+0x6e/0x90 net/socket.c:1960
do_syscall_64+0xb6/0x160 arch/x86/entry/common.c:291
entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x441cf9
Code: 43 02 00 85 c0 b8 00 00 00 00 48 0f 44 c3 5b c3 90 48 89 f8 48 89 f7
48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff
ff 0f 83 0b 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00000000007eff08 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000441cf9
RDX: fffffffffffffee0 RSI: 00000000200005c0 RDI: 0000000000000003
RBP: 00000000007eff30 R08: 0000000000000000 R09: 00000000000000b6
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000403490
R13: 0000000000403520 R14: 0000000000000000 R15: 0000000000000000

Uninit was stored to memory at:
kmsan_save_stack_with_flags mm/kmsan/kmsan.c:151 [inline]
kmsan_internal_chain_origin+0xbd/0x170 mm/kmsan/kmsan.c:319
__msan_chain_origin+0x6b/0xe0 mm/kmsan/kmsan_instr.c:179
__crypto_xor+0x1e8/0x1470 crypto/algapi.c:992
crypto_xor include/crypto/algapi.h:213 [inline]
crypto_cbcmac_digest_update+0x2ba/0x550 crypto/ccm.c:865
crypto_shash_update crypto/shash.c:107 [inline]
shash_ahash_finup+0x659/0xb20 crypto/shash.c:276
shash_async_finup+0xbb/0x110 crypto/shash.c:291
crypto_ahash_op+0x1cd/0x6e0 crypto/ahash.c:368
crypto_ahash_finup+0x8c/0xb0 crypto/ahash.c:393
crypto_ccm_auth+0x14b2/0x1570 crypto/ccm.c:230
crypto_ccm_encrypt+0x283/0x840 crypto/ccm.c:309
crypto_aead_encrypt+0xf2/0x180 crypto/aead.c:99
tls_do_encryption net/tls/tls_sw.c:521 [inline]
tls_push_record+0x341e/0x4e50 net/tls/tls_sw.c:730
bpf_exec_tx_verdict+0x1454/0x1c80 net/tls/tls_sw.c:770
tls_sw_sendmsg+0x158d/0x2710 net/tls/tls_sw.c:1033
inet6_sendmsg+0x2d8/0x2e0 net/ipv6/af_inet6.c:576
sock_sendmsg_nosec net/socket.c:637 [inline]
sock_sendmsg net/socket.c:657 [inline]
__sys_sendto+0x8fc/0xc70 net/socket.c:1952
__do_sys_sendto net/socket.c:1964 [inline]
__se_sys_sendto+0x107/0x130 net/socket.c:1960
__x64_sys_sendto+0x6e/0x90 net/socket.c:1960
do_syscall_64+0xb6/0x160 arch/x86/entry/common.c:291
entry_SYSCALL_64_after_hwframe+0x63/0xe7

Uninit was created at:
kmsan_save_stack_with_flags+0x3f/0x90 mm/kmsan/kmsan.c:151
kmsan_internal_alloc_meta_for_pages mm/kmsan/kmsan_shadow.c:362 [inline]
kmsan_alloc_page+0x153/0x370 mm/kmsan/kmsan_shadow.c:391
__alloc_pages_nodemask+0x149d/0x60c0 mm/page_alloc.c:4794
alloc_pages_current+0x68d/0x9a0 mm/mempolicy.c:2188
alloc_pages include/linux/gfp.h:511 [inline]
skb_page_frag_refill+0x2b0/0x580 net/core/sock.c:2372
sk_page_frag_refill+0xa4/0x330 net/core/sock.c:2392
sk_msg_alloc+0x203/0x1050 net/core/skmsg.c:37
tls_alloc_encrypted_msg net/tls/tls_sw.c:284 [inline]
tls_sw_sendmsg+0xb56/0x2710 net/tls/tls_sw.c:953
inet6_sendmsg+0x2d8/0x2e0 net/ipv6/af_inet6.c:576
sock_sendmsg_nosec net/socket.c:637 [inline]
sock_sendmsg net/socket.c:657 [inline]
__sys_sendto+0x8fc/0xc70 net/socket.c:1952
__do_sys_sendto net/socket.c:1964 [inline]
__se_sys_sendto+0x107/0x130 net/socket.c:1960
__x64_sys_sendto+0x6e/0x90 net/socket.c:1960
do_syscall_64+0xb6/0x160 arch/x86/entry/common.c:291
entry_SYSCALL_64_after_hwframe+0x63/0xe7
=====================================================


---
This bug is generated by a bot. It may contain errors.
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[Eric Biggers]

[+TLS maintainers]

This is a net/tls bug, and probably a duplicate of:

KMSAN: uninit-value in gf128mul_4k_lle (3)
https://lkml.kernel.org/linux-crypto/000000000000bf...@google.com/T/#u

KMSAN: uninit-value in aesti_encrypt
https://lkml.kernel.org/linux-crypto/000000000000a9...@google.com/T/#u

See analysis from Alexander Potapenko here which shows that uninitialized memory
is being passed from TLS subsystem into crypto subsystem:

https://lkml.kernel.org/linux-crypto/CAG_fn=UGCoDk04tL2vB981JmXgo6...@mail.gmail.com/

That was a year ago, with C reproducer, and I've sent several reminders for this
already. What's the ETA on a fix? Or is TLS subsystem de facto unmaintained?

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[Jakub Kicinski]

On Thu, 24 Oct 2019 10:23:53 -0700, Eric Biggers wrote:
> [+TLS maintainers]
>
> This is a net/tls bug, and probably a duplicate of:
>
> KMSAN: uninit-value in gf128mul_4k_lle (3)
> https://lkml.kernel.org/linux-crypto/000000000000bf...@google.com/T/#u
>
> KMSAN: uninit-value in aesti_encrypt
> https://lkml.kernel.org/linux-crypto/000000000000a9...@google.com/T/#u
>
> See analysis from Alexander Potapenko here which shows that uninitialized memory
> is being passed from TLS subsystem into crypto subsystem:
>
> https://lkml.kernel.org/linux-crypto/CAG_fn=UGCoDk04tL2vB981JmXgo6...@mail.gmail.com/
>
> That was a year ago, with C reproducer, and I've sent several reminders for this
> already. What's the ETA on a fix? Or is TLS subsystem de facto unmaintained?

Oh, thanks for the CC, I don't see any of these in my inbox. We have
6 TLS maintainers, the 3 that were CCed on the thread above don't
participate much :(

If nobody beats me to it I'll def take a look on Monday (PTOing this
week).

[Herbert Xu]

On Thu, Oct 24, 2019 at 10:45:37AM -0700, Jakub Kicinski wrote:
>
> Oh, thanks for the CC, I don't see any of these in my inbox. We have
> 6 TLS maintainers, the 3 that were CCed on the thread above don't
> participate much :(

Can you please ensure that all the maintainers are listed in the
MAINTAINERS file so people can cc them when needed?

Thanks,
--
Email: Herbert Xu <her...@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

[Jakub Kicinski]

On Fri, 25 Oct 2019 22:29:25 +0800, Herbert Xu wrote:
> On Thu, Oct 24, 2019 at 10:45:37AM -0700, Jakub Kicinski wrote:
> >
> > Oh, thanks for the CC, I don't see any of these in my inbox. We have
> > 6 TLS maintainers, the 3 that were CCed on the thread above don't
> > participate much :(
>
> Can you please ensure that all the maintainers are listed in the
> MAINTAINERS file so people can cc them when needed?

Yes, to be clear we are all listed. Coincidentally we're listed in
order of addition, which turns out to be reverse to the amount of
caring.. And in the threads above it seems someone decided to only
CC first few (i.e. the oldest, i.e. the least caring).

I'll send a patch to remove Dave Watson at least. He's FB email address
is dead, I've been trying to get in touch with him for 2 months with no
luck..

[Jakub Kicinski]

On Thu, 24 Oct 2019 10:23:53 -0700, Eric Biggers wrote:

> [+TLS maintainers]
>
> This is a net/tls bug, and probably a duplicate of:
>
> KMSAN: uninit-value in gf128mul_4k_lle (3)
> https://lkml.kernel.org/linux-crypto/000000000000bf...@google.com/T/#u
>
> KMSAN: uninit-value in aesti_encrypt
> https://lkml.kernel.org/linux-crypto/000000000000a9...@google.com/T/#u
>
> See analysis from Alexander Potapenko here which shows that uninitialized memory
> is being passed from TLS subsystem into crypto subsystem:
>
> https://lkml.kernel.org/linux-crypto/CAG_fn=UGCoDk04tL2vB981JmXgo6...@mail.gmail.com/
>
> That was a year ago, with C reproducer, and I've sent several reminders for this
> already. What's the ETA on a fix? Or is TLS subsystem de facto unmaintained?

Re: maintainers it may actually be that the bug is so old the people
who pay attention weren't in the MAINTAINERS yet ;) That'd explain why
Alexander didn't CC us.

Fix posted now:

net/tls: fix sk_msg trim on fallback to copy mode

🤞

[Eric Biggers]

On Wed, Oct 30, 2019 at 09:08:19AM -0700, Jakub Kicinski wrote:
>
> Fix posted now:
>
> net/tls: fix sk_msg trim on fallback to copy mode
>

Thanks! That commit missed a Reported-by line for this syzbot report (instead
including 2 others), so let's tell syzbot this one was a duplicate:

#syz dup: KMSAN: uninit-value in aesti_encrypt