[syzbot] [crypto?] general protection fault in shash_async_update

syzbot
2023-06-23T14:36:48Z

Hello,

syzbot found the following issue on:

HEAD commit: 26a4dd839eeb selftests: net: vxlan: Fix selftest regressio..
git tree: net-next
console+strace: https://syzkaller.appspot.com/x/log.txt?x=169f932d280000
kernel config: https://syzkaller.appspot.com/x/.config?x=526f919910d4a671
dashboard link: https://syzkaller.appspot.com/bug?extid=0bc501b7bf9e1bc09958
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=13f71275280000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11081055280000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/8b8b1725013b/disk-26a4dd83.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/b9906d975821/vmlinux-26a4dd83.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b968b241eeb1/bzImage-26a4dd83.xz

The issue was bisected to:

commit c662b043cdca89bf0f03fc37251000ac69a3a548
Author: David Howells <dhowells@redhat.com>
Date: Tue Jun 6 13:08:56 2023 +0000

crypto: af_alg/hash: Support MSG_SPLICE_PAGES

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1023cfdf280000
final oops: https://syzkaller.appspot.com/x/report.txt?x=1223cfdf280000
console output: https://syzkaller.appspot.com/x/log.txt?x=1423cfdf280000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+0bc501b7bf9e1bc09958@syzkaller.appspotmail.com
Fixes: c662b043cdca ("crypto: af_alg/hash: Support MSG_SPLICE_PAGES")

general protection fault, probably for non-canonical address 0xdffffc0000000004: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000020-0x0000000000000027]
CPU: 0 PID: 5005 Comm: syz-executor418 Not tainted 6.4.0-rc5-syzkaller-01111-g26a4dd839eeb #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023
RIP: 0010:crypto_shash_alg include/crypto/hash.h:827 [inline]
RIP: 0010:crypto_shash_update crypto/shash.c:124 [inline]
RIP: 0010:shash_ahash_update crypto/shash.c:306 [inline]
RIP: 0010:shash_async_update+0x130/0x210 crypto/shash.c:314
Code: 36 0c a5 fd 48 8b 44 24 08 48 8b 6c 24 48 80 38 00 0f 85 c3 00 00 00 48 8b 04 24 4c 8b 68 50 49 8d 7d 20 48 89 fa 48 c1 ea 03 <80> 3c 1a 00 0f 85 bd 00 00 00 4d 8b 75 20 49 8d 7e 2c 48 89 fa 48
RSP: 0018:ffffc90003a1f968 EFLAGS: 00010202
RAX: ffff8880206b02a8 RBX: dffffc0000000000 RCX: 0000000000000000
RDX: 0000000000000004 RSI: ffffffff83df3a1a RDI: 0000000000000020
RBP: ffff888072b43240 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000dc0 R11: 0000000000000009 R12: 0000000000000dc0
R13: 0000000000000000 R14: 1ffff110040d605f R15: ffff8880206b02f8
FS: 0000555557028300(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4ef51f2304 CR3: 000000001328b000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
crypto_ahash_update include/crypto/hash.h:608 [inline]
hash_sendmsg+0x434/0xde0 crypto/algif_hash.c:139
sock_sendmsg_nosec net/socket.c:724 [inline]
sock_sendmsg+0xde/0x190 net/socket.c:747
____sys_sendmsg+0x733/0x920 net/socket.c:2493
___sys_sendmsg+0x110/0x1b0 net/socket.c:2547
__sys_sendmsg+0xf7/0x1c0 net/socket.c:2576
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f71e8ca1c89
Code: 28 c3 e8 2a 14 00 00 66 2e 0f 1f 84 00 00 00 00 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 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffebca0c5d8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f71e8ca1c89
RDX: 0000000000000000 RSI: 0000000020000300 RDI: 0000000000000004
RBP: 00007f71e8c65e30 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f71e8c65ec0
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:crypto_shash_alg include/crypto/hash.h:827 [inline]
RIP: 0010:crypto_shash_update crypto/shash.c:124 [inline]
RIP: 0010:shash_ahash_update crypto/shash.c:306 [inline]
RIP: 0010:shash_async_update+0x130/0x210 crypto/shash.c:314
Code: 36 0c a5 fd 48 8b 44 24 08 48 8b 6c 24 48 80 38 00 0f 85 c3 00 00 00 48 8b 04 24 4c 8b 68 50 49 8d 7d 20 48 89 fa 48 c1 ea 03 <80> 3c 1a 00 0f 85 bd 00 00 00 4d 8b 75 20 49 8d 7e 2c 48 89 fa 48
RSP: 0018:ffffc90003a1f968 EFLAGS: 00010202
RAX: ffff8880206b02a8 RBX: dffffc0000000000 RCX: 0000000000000000
RDX: 0000000000000004 RSI: ffffffff83df3a1a RDI: 0000000000000020
RBP: ffff888072b43240 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000dc0 R11: 0000000000000009 R12: 0000000000000dc0
R13: 0000000000000000 R14: 1ffff110040d605f R15: ffff8880206b02f8
FS: 0000555557028300(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffebcaca020 CR3: 000000001328b000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 36 0c a5 ss or $0xa5,%al
3: fd std
4: 48 8b 44 24 08 mov 0x8(%rsp),%rax
9: 48 8b 6c 24 48 mov 0x48(%rsp),%rbp
e: 80 38 00 cmpb $0x0,(%rax)
11: 0f 85 c3 00 00 00 jne 0xda
17: 48 8b 04 24 mov (%rsp),%rax
1b: 4c 8b 68 50 mov 0x50(%rax),%r13
1f: 49 8d 7d 20 lea 0x20(%r13),%rdi
23: 48 89 fa mov %rdi,%rdx
26: 48 c1 ea 03 shr $0x3,%rdx
* 2a: 80 3c 1a 00 cmpb $0x0,(%rdx,%rbx,1) <-- trapping instruction
2e: 0f 85 bd 00 00 00 jne 0xf1
34: 4d 8b 75 20 mov 0x20(%r13),%r14
38: 49 8d 7e 2c lea 0x2c(%r14),%rdi
3c: 48 89 fa mov %rdi,%rdx
3f: 48 rex.W

---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
For information about bisection process see: https://goo.gl/tpsmEJ#bisection

If the bug is already fixed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

If you want to change bug's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the bug is a duplicate of another bug, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup