Subject: [syzbot] [net?] BUG: corrupted list in ptp_open

From: syzbot <[email-masked]>
Date: Thu, 26 Oct 2023 07:20:20 -0700

Hello,

syzbot found the following issue on:

HEAD commit:    2030579113a1 Add linux-next specific files for 20231020
git tree:       linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=16ab79a3680000
kernel config:  https://syzkaller.appspot.com/x/.config?x=37404d76b3c8840e
dashboard link: https://syzkaller.appspot.com/bug?extid=df3f3ef31f60781fa911
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=140aa715680000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=11037669680000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/a99a981e5d78/disk-20305791.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/073a5ba6a2a6/vmlinux-20305791.xz
kernel image: https://storage.googleapis.com/syzbot-assets/c7c1a7107f7b/bzImage-20305791.xz

The issue was bisected to:

commit 8f5de6fb245326704f37d91780b9a10253a8a100
Author: Xabier Marquiegui <[email-masked]>
Date:   Wed Oct 11 22:39:55 2023 +0000

    ptp: support multiple timestamp event readers

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=15475b89680000
final oops:     https://syzkaller.appspot.com/x/report.txt?x=17475b89680000
console output: https://syzkaller.appspot.com/x/log.txt?x=13475b89680000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: [email-masked]
Fixes: 8f5de6fb2453 ("ptp: support multiple timestamp event readers")

list_add corruption. prev->next should be next (ffff88814a1325e8), but was ffff888078d25048. (prev=ffff888078d21048).
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:32!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 7237 Comm: syz-executor182 Not tainted 6.6.0-rc6-next-20231020-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023
RIP: 0010:__list_add_valid_or_report+0xb6/0x100 lib/list_debug.c:32
Code: e8 2f a5 3a fd 0f 0b 48 89 d9 48 c7 c7 40 9d e9 8a e8 1e a5 3a fd 0f 0b 48 89 f1 48 c7 c7 c0 9d e9 8a 48 89 de e8 0a a5 3a fd <0f> 0b 48 89 f2 48 89 d9 48 89 ee 48 c7 c7 40 9e e9 8a e8 f3 a4 3a
RSP: 0018:ffffc90009b3f898 EFLAGS: 00010286
RAX: 0000000000000075 RBX: ffff88814a1325e8 RCX: ffffffff816bb8d9
RDX: 0000000000000000 RSI: ffffffff816c4d42 RDI: 0000000000000005
RBP: ffff88807c7a9048 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000080000000 R11: 0000000000000001 R12: ffff88814a132000
R13: ffffc90009b3f900 R14: ffff888078d21048 R15: ffff88807c7a9048
FS:  0000555556c00380(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffef0aa1138 CR3: 000000007d17e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __list_add_valid include/linux/list.h:88 [inline]
 __list_add include/linux/list.h:150 [inline]
 list_add_tail include/linux/list.h:183 [inline]
 ptp_open+0x1c5/0x4f0 drivers/ptp/ptp_chardev.c:122
 posix_clock_open+0x17e/0x240 kernel/time/posix-clock.c:134
 chrdev_open+0x26d/0x6e0 fs/char_dev.c:414
 do_dentry_open+0x8d4/0x18d0 fs/open.c:948
 do_open fs/namei.c:3621 [inline]
 path_openat+0x1d36/0x2cd0 fs/namei.c:3778
 do_filp_open+0x1dc/0x430 fs/namei.c:3808
 do_sys_openat2+0x176/0x1e0 fs/open.c:1440
 do_sys_open fs/open.c:1455 [inline]
 __do_sys_openat fs/open.c:1471 [inline]
 __se_sys_openat fs/open.c:1466 [inline]
 __x64_sys_openat+0x175/0x210 fs/open.c:1466
 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+0x63/0x6b
RIP: 0033:0x7fc6c2099ae9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 c1 17 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffef0aa1238 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fc6c2099ae9
RDX: 0000000000000000 RSI: 0000000020000300 RDI: ffffffffffffff9c
RBP: 00000000000f4240 R08: 0000000000000000 R09: 00000000000000a0
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000000130fc
R13: 00007ffef0aa124c R14: 00007ffef0aa1260 R15: 00007ffef0aa1250
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__list_add_valid_or_report+0xb6/0x100 lib/list_debug.c:32
Code: e8 2f a5 3a fd 0f 0b 48 89 d9 48 c7 c7 40 9d e9 8a e8 1e a5 3a fd 0f 0b 48 89 f1 48 c7 c7 c0 9d e9 8a 48 89 de e8 0a a5 3a fd <0f> 0b 48 89 f2 48 89 d9 48 89 ee 48 c7 c7 40 9e e9 8a e8 f3 a4 3a
RSP: 0018:ffffc90009b3f898 EFLAGS: 00010286
RAX: 0000000000000075 RBX: ffff88814a1325e8 RCX: ffffffff816bb8d9
RDX: 0000000000000000 RSI: ffffffff816c4d42 RDI: 0000000000000005
RBP: ffff88807c7a9048 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000080000000 R11: 0000000000000001 R12: ffff88814a132000
R13: ffffc90009b3f900 R14: ffff888078d21048 R15: ffff88807c7a9048
FS:  0000555556c00380(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffef0aa1138 CR3: 000000007d17e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

---
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