Re: KMSAN: uninit-value in aesti_encrypt

syzbot
2019-06-27T17:14:08Z

syzbot has found a reproducer for the following crash on:

HEAD commit: 41550654 [UPSTREAM] KVM: x86: degrade WARN to pr_warn_rate..
git tree: kmsan
console output: https://syzkaller.appspot.com/x/log.txt?x=11302ccba00000
kernel config: https://syzkaller.appspot.com/x/.config?x=40511ad0c5945201
dashboard link: https://syzkaller.appspot.com/bug?extid=6f50c99e8f6194bf363f
compiler: clang version 9.0.0 (/home/glider/llvm/clang
80fee25776c2fb61e74c1ecb1a523375c2500b69)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12906f79a00000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14355961a00000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+6f50c99e8f6194bf363f@syzkaller.appspotmail.com

==================================================================
BUG: KMSAN: uninit-value in subshift crypto/aes_ti.c:148 [inline]
BUG: KMSAN: uninit-value in aesti_encrypt+0x1238/0x1bc0 crypto/aes_ti.c:292
CPU: 0 PID: 11119 Comm: syz-executor333 Not tainted 5.2.0-rc4+ #7
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+0x162/0x2d0 mm/kmsan/kmsan.c:611
__msan_warning+0x75/0xe0 mm/kmsan/kmsan_instr.c:304
subshift crypto/aes_ti.c:148 [inline]
aesti_encrypt+0x1238/0x1bc0 crypto/aes_ti.c:292
crypto_cipher_encrypt_one include/linux/crypto.h:1753 [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+0x272/0x8d0 crypto/ccm.c:309
crypto_aead_encrypt include/crypto/aead.h:331 [inline]
tls_do_encryption net/tls/tls_sw.c:521 [inline]
tls_push_record+0x341a/0x4f70 net/tls/tls_sw.c:730
bpf_exec_tx_verdict+0x1454/0x1c90 net/tls/tls_sw.c:770
tls_sw_sendmsg+0x15bd/0x2740 net/tls/tls_sw.c:1033
inet_sendmsg+0x48e/0x750 net/ipv4/af_inet.c:798
sock_sendmsg_nosec net/socket.c:646 [inline]
sock_sendmsg net/socket.c:665 [inline]
__sys_sendto+0x905/0xb90 net/socket.c:1958
__do_sys_sendto net/socket.c:1970 [inline]
__se_sys_sendto+0x107/0x130 net/socket.c:1966
__x64_sys_sendto+0x6e/0x90 net/socket.c:1966
do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:302
entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x4402d9
Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 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 fb 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffcef4112e8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 00000000004402d9
RDX: ffffffffffffff7f RSI: 00000000200005c0 RDI: 0000000000000003
RBP: 00000000006ca018 R08: 0000000000000000 R09: fffffffffffffd56
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401b60
R13: 0000000000401bf0 R14: 0000000000000000 R15: 0000000000000000

Uninit was stored to memory at:
kmsan_save_stack_with_flags mm/kmsan/kmsan.c:201 [inline]
kmsan_save_stack mm/kmsan/kmsan.c:213 [inline]
kmsan_internal_chain_origin+0xcc/0x150 mm/kmsan/kmsan.c:414
__msan_chain_origin+0x6b/0xe0 mm/kmsan/kmsan_instr.c:200
__crypto_xor+0x1e8/0x1470 crypto/algapi.c:1019
crypto_xor include/crypto/algapi.h:214 [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+0x272/0x8d0 crypto/ccm.c:309
crypto_aead_encrypt include/crypto/aead.h:331 [inline]
tls_do_encryption net/tls/tls_sw.c:521 [inline]
tls_push_record+0x341a/0x4f70 net/tls/tls_sw.c:730
bpf_exec_tx_verdict+0x1454/0x1c90 net/tls/tls_sw.c:770
tls_sw_sendmsg+0x15bd/0x2740 net/tls/tls_sw.c:1033
inet_sendmsg+0x48e/0x750 net/ipv4/af_inet.c:798
sock_sendmsg_nosec net/socket.c:646 [inline]
sock_sendmsg net/socket.c:665 [inline]
__sys_sendto+0x905/0xb90 net/socket.c:1958
__do_sys_sendto net/socket.c:1970 [inline]
__se_sys_sendto+0x107/0x130 net/socket.c:1966
__x64_sys_sendto+0x6e/0x90 net/socket.c:1966
do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:302
entry_SYSCALL_64_after_hwframe+0x63/0xe7

Uninit was created at:
kmsan_save_stack_with_flags+0x37/0x70 mm/kmsan/kmsan.c:201
kmsan_internal_alloc_meta_for_pages+0x123/0x510 mm/kmsan/kmsan_hooks.c:103
kmsan_alloc_page+0x7a/0xf0 mm/kmsan/kmsan_hooks.c:247
__alloc_pages_nodemask+0x144d/0x6020 mm/page_alloc.c:4700
alloc_pages_current+0x6a0/0x9b0 mm/mempolicy.c:2132
alloc_pages include/linux/gfp.h:511 [inline]
skb_page_frag_refill+0x15e/0x560 net/core/sock.c:2349
sk_page_frag_refill+0xa4/0x330 net/core/sock.c:2369
sk_msg_alloc+0x203/0x1050 net/core/skmsg.c:37
tls_alloc_encrypted_msg net/tls/tls_sw.c:284 [inline]
tls_sw_sendmsg+0xb6a/0x2740 net/tls/tls_sw.c:953
inet_sendmsg+0x48e/0x750 net/ipv4/af_inet.c:798
sock_sendmsg_nosec net/socket.c:646 [inline]
sock_sendmsg net/socket.c:665 [inline]
__sys_sendto+0x905/0xb90 net/socket.c:1958
__do_sys_sendto net/socket.c:1970 [inline]
__se_sys_sendto+0x107/0x130 net/socket.c:1966
__x64_sys_sendto+0x6e/0x90 net/socket.c:1966
do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:302
entry_SYSCALL_64_after_hwframe+0x63/0xe7
==================================================================