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

From: syzbot
Date: Mon Jun 12 2023 - 06:03:01 EST


Hello,

syzbot found the following issue on:

HEAD commit: e431e712c836 Merge branch 'sfc-tc-encap-actions-offload'
git tree: net-next
console+strace: https://syzkaller.appspot.com/x/log.txt?x=17e7771b280000
kernel config: https://syzkaller.appspot.com/x/.config?x=526f919910d4a671
dashboard link: https://syzkaller.appspot.com/bug?extid=4e2e47f32607d0f72d43
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=12610c75280000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=171cdef1280000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/35e2db144233/disk-e431e712.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/ecf37a1cef2c/vmlinux-e431e712.xz
kernel image: https://storage.googleapis.com/syzbot-assets/a3da92090562/bzImage-e431e712.xz

The issue was bisected to:

commit c662b043cdca89bf0f03fc37251000ac69a3a548
Author: David Howells <dhowells@xxxxxxxxxx>
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=12392407280000
final oops: https://syzkaller.appspot.com/x/report.txt?x=11392407280000
console output: https://syzkaller.appspot.com/x/log.txt?x=16392407280000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+4e2e47f32607d0f72d43@xxxxxxxxxxxxxxxxxxxxxxxxx
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: 9 Comm: kworker/0:1 Not tainted 6.4.0-rc5-syzkaller-01107-ge431e712c836 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023
Workqueue: cryptd cryptd_queue_worker
RIP: 0010:crypto_shash_alg include/crypto/hash.h:827 [inline]
RIP: 0010:crypto_shash_finup+0x53/0x160 crypto/shash.c:198
Code: fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 05 01 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b 5d 00 48 8d 7b 20 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 d8 00 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8b
RSP: 0018:ffffc900000e7ba0 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000004 RSI: ffffffff83df35bf RDI: 0000000000000020
RBP: ffff888028350b08 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 1ffffffff218470c R12: ffff8880123fa1c0
R13: ffff888029582ac8 R14: 0000000000000014 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f251034e440 CR3: 000000007cc84000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
shash_ahash_finup+0xdf/0x3a0 crypto/shash.c:333
cryptd_hash_finup+0xce/0x120 crypto/cryptd.c:597
crypto_request_complete include/crypto/algapi.h:272 [inline]
cryptd_queue_worker+0x130/0x1d0 crypto/cryptd.c:181
process_one_work+0x99a/0x15e0 kernel/workqueue.c:2405
worker_thread+0x67d/0x10c0 kernel/workqueue.c:2552
kthread+0x344/0x440 kernel/kthread.c:379
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:crypto_shash_alg include/crypto/hash.h:827 [inline]
RIP: 0010:crypto_shash_finup+0x53/0x160 crypto/shash.c:198
Code: fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 05 01 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b 5d 00 48 8d 7b 20 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 d8 00 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8b
RSP: 0018:ffffc900000e7ba0 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000004 RSI: ffffffff83df35bf RDI: 0000000000000020
RBP: ffff888028350b08 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 1ffffffff218470c R12: ffff8880123fa1c0
R13: ffff888029582ac8 R14: 0000000000000014 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f251034e440 CR3: 000000002aa8e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess), 3 bytes skipped:
0: 48 c1 ea 03 shr $0x3,%rdx
4: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1)
8: 0f 85 05 01 00 00 jne 0x113
e: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
15: fc ff df
18: 48 8b 5d 00 mov 0x0(%rbp),%rbx
1c: 48 8d 7b 20 lea 0x20(%rbx),%rdi
20: 48 89 fa mov %rdi,%rdx
23: 48 c1 ea 03 shr $0x3,%rdx
* 27: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) <-- trapping instruction
2b: 0f 85 d8 00 00 00 jne 0x109
31: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
38: fc ff df
3b: 4c rex.WR
3c: 8b .byte 0x8b


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