Re: [syzbot] [crypto?] general protection fault in scatterwalk_copychunks (5)

From: syzbot
Date: Tue Dec 26 2023 - 21:42:13 EST

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
general protection fault in scatterwalk_copychunks

general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
CPU: 0 PID: 5477 Comm: syz-executor.0 Not tainted 6.7.0-rc6-next-20231222-syzkaller-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
RIP: 0010:scatterwalk_start include/crypto/scatterwalk.h:63 [inline]
RIP: 0010:scatterwalk_pagedone include/crypto/scatterwalk.h:83 [inline]
RIP: 0010:scatterwalk_pagedone include/crypto/scatterwalk.h:72 [inline]
RIP: 0010:scatterwalk_copychunks+0x3e0/0x560 crypto/scatterwalk.c:50
Code: f0 48 c1 e8 03 80 3c 08 00 0f 85 81 01 00 00 49 8d 44 24 08 4d 89 26 48 bf 00 00 00 00 00 fc ff df 48 89 44 24 10 48 c1 e8 03 <0f> b6 04 38 84 c0 74 08 3c 03 0f 8e 47 01 00 00 48 8b 44 24 08 41
RSP: 0018:ffffc9000557ecf0 EFLAGS: 00010202
RAX: 0000000000000001 RBX: 0000000000000000 RCX: dffffc0000000000
RDX: ffff88807fc6d940 RSI: ffffffff8465df94 RDI: dffffc0000000000
RBP: 0000000000001000 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000002 R11: 82d8bd1b6060f805 R12: 0000000000000000
R13: 0000000000000014 R14: ffffc9000557ed88 R15: 0000000000001000
FS: 00007ff79da616c0(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff79cd98000 CR3: 0000000021251000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
scatterwalk_map_and_copy+0x151/0x1d0 crypto/scatterwalk.c:67
scomp_acomp_comp_decomp+0x3a3/0x780 crypto/scompress.c:149
crypto_acomp_compress include/crypto/acompress.h:302 [inline]
zswap_store+0x98b/0x2430 mm/zswap.c:1666
swap_writepage+0x8e/0x220 mm/page_io.c:198
pageout+0x399/0x9e0 mm/vmscan.c:656
shrink_folio_list+0x2f47/0x3ea0 mm/vmscan.c:1319
reclaim_folio_list+0xe4/0x3a0 mm/vmscan.c:2104
reclaim_pages+0x483/0x6a0 mm/vmscan.c:2140
madvise_cold_or_pageout_pte_range+0x129e/0x1f70 mm/madvise.c:526
walk_pmd_range mm/pagewalk.c:143 [inline]
walk_pud_range mm/pagewalk.c:221 [inline]
walk_p4d_range mm/pagewalk.c:256 [inline]
walk_pgd_range+0xa48/0x1870 mm/pagewalk.c:293
__walk_page_range+0x630/0x770 mm/pagewalk.c:395
walk_page_range+0x626/0xa80 mm/pagewalk.c:521
madvise_pageout_page_range mm/madvise.c:585 [inline]
madvise_pageout+0x32c/0x820 mm/madvise.c:612
madvise_vma_behavior+0x1cc/0x1b50 mm/madvise.c:1031
madvise_walk_vmas+0x1cf/0x2c0 mm/madvise.c:1260
do_madvise+0x349/0x670 mm/madvise.c:1443
__do_sys_madvise mm/madvise.c:1456 [inline]
__se_sys_madvise mm/madvise.c:1454 [inline]
__x64_sys_madvise+0xa9/0x110 mm/madvise.c:1454
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0x40/0x110 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x62/0x6a
RIP: 0033:0x7ff79cc7cce9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 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 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff79da610c8 EFLAGS: 00000246 ORIG_RAX: 000000000000001c
RAX: ffffffffffffffda RBX: 00007ff79cd9bf80 RCX: 00007ff79cc7cce9
RDX: 0000000000000015 RSI: 0000000000c00304 RDI: 0000000020000000
RBP: 00007ff79ccc947a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007ff79cd9bf80 R15: 00007ffc0bca2f58
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:scatterwalk_start include/crypto/scatterwalk.h:63 [inline]
RIP: 0010:scatterwalk_pagedone include/crypto/scatterwalk.h:83 [inline]
RIP: 0010:scatterwalk_pagedone include/crypto/scatterwalk.h:72 [inline]
RIP: 0010:scatterwalk_copychunks+0x3e0/0x560 crypto/scatterwalk.c:50
Code: f0 48 c1 e8 03 80 3c 08 00 0f 85 81 01 00 00 49 8d 44 24 08 4d 89 26 48 bf 00 00 00 00 00 fc ff df 48 89 44 24 10 48 c1 e8 03 <0f> b6 04 38 84 c0 74 08 3c 03 0f 8e 47 01 00 00 48 8b 44 24 08 41
RSP: 0018:ffffc9000557ecf0 EFLAGS: 00010202
RAX: 0000000000000001 RBX: 0000000000000000 RCX: dffffc0000000000
RDX: ffff88807fc6d940 RSI: ffffffff8465df94 RDI: dffffc0000000000
RBP: 0000000000001000 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000002 R11: 82d8bd1b6060f805 R12: 0000000000000000
R13: 0000000000000014 R14: ffffc9000557ed88 R15: 0000000000001000
FS: 00007ff79da616c0(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff79cd98000 CR3: 0000000021251000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: f0 48 c1 e8 03 lock shr $0x3,%rax
5: 80 3c 08 00 cmpb $0x0,(%rax,%rcx,1)
9: 0f 85 81 01 00 00 jne 0x190
f: 49 8d 44 24 08 lea 0x8(%r12),%rax
14: 4d 89 26 mov %r12,(%r14)
17: 48 bf 00 00 00 00 00 movabs $0xdffffc0000000000,%rdi
1e: fc ff df
21: 48 89 44 24 10 mov %rax,0x10(%rsp)
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 0f b6 04 38 movzbl (%rax,%rdi,1),%eax <-- trapping instruction
2e: 84 c0 test %al,%al
30: 74 08 je 0x3a
32: 3c 03 cmp $0x3,%al
34: 0f 8e 47 01 00 00 jle 0x181
3a: 48 8b 44 24 08 mov 0x8(%rsp),%rax
3f: 41 rex.B


Tested on:

commit: 39676dfe Add linux-next specific files for 20231222
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
console output: https://syzkaller.appspot.com/x/log.txt?x=11c37595e80000
kernel config: https://syzkaller.appspot.com/x/.config?x=f3761490b734dc96
dashboard link: https://syzkaller.appspot.com/bug?extid=3eff5e51bf1db122a16e
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
patch: https://syzkaller.appspot.com/x/patch.diff?x=12fb5776e80000