[syzbot] [net?] general protection fault in tls_merge_open_record

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 66f1e1ea3548 Add linux-next specific files for 20231027
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=11b621fd680000
kernel config: https://syzkaller.appspot.com/x/.config?x=2911330219149de4
dashboard link: https://syzkaller.appspot.com/bug?extid=40d43509a099ea756317
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1552332d680000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/e0bf12f215f2/disk-66f1e1ea.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/5e854ca6e2c3/vmlinux-66f1e1ea.xz
kernel image: https://storage.googleapis.com/syzbot-assets/25e8c098714e/bzImage-66f1e1ea.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+40d435...@syzkaller.appspotmail.com

general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
CPU: 1 PID: 12569 Comm: syz-executor.0 Not tainted 6.6.0-rc7-next-20231027-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
RIP: 0010:_compound_head include/linux/page-flags.h:247 [inline]
RIP: 0010:put_page include/linux/mm.h:1544 [inline]
RIP: 0010:tls_merge_open_record+0x4b9/0x7f0 net/tls/tls_sw.c:669
Code: 85 e4 0f 85 b6 02 00 00 e8 54 62 67 f8 4d 89 f4 48 b8 00 00 00 00 00 fc ff df 49 83 e4 fc 49 8d 7c 24 08 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 ed 02 00 00 4d 8b 6c 24 08 31 ff 4d 89 ef 41 83
RSP: 0018:ffffc9000ae9f498 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff888068caa000 RCX: ffffffff89219a8e
RDX: 0000000000000001 RSI: ffffffff89219a9c RDI: 0000000000000008
RBP: ffff888068cab000 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff81dfefa3 R12: 0000000000000000
R13: 0000000000000020 R14: 0000000000000000 R15: 0000000000000000
FS: 00007fa3e0ea76c0(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020173000 CR3: 00000000279dd000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
tls_push_record+0x290f/0x3070 net/tls/tls_sw.c:726
bpf_exec_tx_verdict+0xdee/0x1230 net/tls/tls_sw.c:819
tls_sw_splice_eof+0x194/0x470 net/tls/tls_sw.c:1242
sock_splice_eof+0x86/0xb0 net/socket.c:1116
direct_file_splice_eof+0x86/0xb0 fs/splice.c:1151
do_splice_eof fs/splice.c:944 [inline]
splice_direct_to_actor+0x710/0xa30 fs/splice.c:1117
do_splice_direct+0x1af/0x280 fs/splice.c:1194
do_sendfile+0xb3a/0x1310 fs/read_write.c:1254
__do_sys_sendfile64 fs/read_write.c:1322 [inline]
__se_sys_sendfile64 fs/read_write.c:1308 [inline]
__x64_sys_sendfile64+0x1d6/0x220 fs/read_write.c:1308
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x3f/0x110 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x62/0x6a
RIP: 0033:0x7fa3e007cae9
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:00007fa3e0ea70c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007fa3e019c050 RCX: 00007fa3e007cae9
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000003
RBP: 00007fa3e00c847a R08: 0000000000000000 R09: 0000000000000000
R10: 00000000f2090293 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007fa3e019c050 R15: 00007ffcc0dbba98
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:_compound_head include/linux/page-flags.h:247 [inline]
RIP: 0010:put_page include/linux/mm.h:1544 [inline]
RIP: 0010:tls_merge_open_record+0x4b9/0x7f0 net/tls/tls_sw.c:669
Code: 85 e4 0f 85 b6 02 00 00 e8 54 62 67 f8 4d 89 f4 48 b8 00 00 00 00 00 fc ff df 49 83 e4 fc 49 8d 7c 24 08 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 ed 02 00 00 4d 8b 6c 24 08 31 ff 4d 89 ef 41 83
RSP: 0018:ffffc9000ae9f498 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff888068caa000 RCX: ffffffff89219a8e
RDX: 0000000000000001 RSI: ffffffff89219a9c RDI: 0000000000000008
RBP: ffff888068cab000 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff81dfefa3 R12: 0000000000000000
R13: 0000000000000020 R14: 0000000000000000 R15: 0000000000000000
FS: 00007fa3e0ea76c0(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020347000 CR3: 00000000279dd000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 85 e4 test %esp,%esp
2: 0f 85 b6 02 00 00 jne 0x2be
8: e8 54 62 67 f8 call 0xf8676261
d: 4d 89 f4 mov %r14,%r12
10: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
17: fc ff df
1a: 49 83 e4 fc and $0xfffffffffffffffc,%r12
1e: 49 8d 7c 24 08 lea 0x8(%r12),%rdi
23: 48 89 fa mov %rdi,%rdx
26: 48 c1 ea 03 shr $0x3,%rdx
* 2a: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) <-- trapping instruction
2e: 0f 85 ed 02 00 00 jne 0x321
34: 4d 8b 6c 24 08 mov 0x8(%r12),%r13
39: 31 ff xor %edi,%edi
3b: 4d 89 ef mov %r13,%r15
3e: 41 rex.B
3f: 83 .byte 0x83


---
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 syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

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 overwrite 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

[Jann Horn]

On Mon, Oct 30, 2023 at 6:52 AM syzbot
<syzbot+40d435...@syzkaller.appspotmail.com> wrote:
>
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: 66f1e1ea3548 Add linux-next specific files for 20231027
> git tree: linux-next
> console output: https://syzkaller.appspot.com/x/log.txt?x=11b621fd680000
> kernel config: https://syzkaller.appspot.com/x/.config?x=2911330219149de4
> dashboard link: https://syzkaller.appspot.com/bug?extid=40d43509a099ea756317
> compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1552332d680000
>
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/e0bf12f215f2/disk-66f1e1ea.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/5e854ca6e2c3/vmlinux-66f1e1ea.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/25e8c098714e/bzImage-66f1e1ea.xz
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+40d435...@syzkaller.appspotmail.com
>
> general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN
> KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
> CPU: 1 PID: 12569 Comm: syz-executor.0 Not tainted 6.6.0-rc7-next-20231027-syzkaller #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
> RIP: 0010:_compound_head include/linux/page-flags.h:247 [inline]
> RIP: 0010:put_page include/linux/mm.h:1544 [inline]
> RIP: 0010:tls_merge_open_record+0x4b9/0x7f0 net/tls/tls_sw.c:669

I've posted an analysis and suggested fix for the issue at
<https://lore.kernel.org/lkml/20231122214447...@google.com/>.