Hello,

syzbot found the following issue on:

HEAD commit: 0a093b2893c7 Add linux-next specific files for 20230112 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=108e6329480000 kernel config: https://syzkaller.appspot.com/x/.config?x=835f3591019836d5 dashboard link: https://syzkaller.appspot.com/bug?extid=d7cf279f42a3353263b2 compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/8111a570d6cb/disk-0a093b28.raw.... vmlinux: https://storage.googleapis.com/syzbot-assets/ecc135b7fc9a/vmlinux-0a093b28.x... kernel image: https://storage.googleapis.com/syzbot-assets/ca8d73b446ea/bzImage-0a093b28.x...

IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+d7cf279f42a3353263b2@syzkaller.appspotmail.com

general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017] CPU: 0 PID: 5386 Comm: syz-executor.2 Not tainted 6.2.0-rc3-next-20230112-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 RIP: 0010:snd_rawmidi_kernel_write1+0x82/0x870 sound/core/rawmidi.c:1517 Code: a0 00 00 00 0f 84 44 05 00 00 e8 d9 a3 e7 f9 49 8d 44 24 10 48 89 c2 48 89 44 24 28 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80> 3c 02 00 0f 85 cf 07 00 00 49 83 7c 24 10 00 0f 84 da 05 00 00 RSP: 0018:ffffc90004f77b88 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: ffff888026110500 RCX: ffffc900040a1000 RDX: 0000000000000002 RSI: ffffffff879a1907 RDI: ffff8880261105a0 RBP: 0000000000001000 R08: 0000000000000001 R09: 0000000000000001 R10: ffffed1004c220a6 R11: 0000000000000000 R12: 0000000000000000 R13: 000000007f078000 R14: 0000000000000000 R15: ffffc90004f77cc0 FS: 00007fc907fb2700(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020f86000 CR3: 000000007a7c6000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> snd_rawmidi_write+0x277/0xbb0 sound/core/rawmidi.c:1616 vfs_write+0x2db/0xe10 fs/read_write.c:582 ksys_write+0x1ec/0x250 fs/read_write.c:637 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: 0033:0x7fc90728c0c9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 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:00007fc907fb2168 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fc9073ac050 RCX: 00007fc90728c0c9 RDX: 00000000fffffd2c RSI: 0000000020000000 RDI: 0000000000000007 RBP: 00007fc9072e7ae9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc1a5a1b9f R14: 00007fc907fb2300 R15: 0000000000022000 </TASK> Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:snd_rawmidi_kernel_write1+0x82/0x870 sound/core/rawmidi.c:1517 Code: a0 00 00 00 0f 84 44 05 00 00 e8 d9 a3 e7 f9 49 8d 44 24 10 48 89 c2 48 89 44 24 28 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80> 3c 02 00 0f 85 cf 07 00 00 49 83 7c 24 10 00 0f 84 da 05 00 00 ---------------- Code disassembly (best guess): 0: a0 00 00 00 0f 84 44 movabs 0x544840f000000,%al 7: 05 00 9: 00 e8 add %ch,%al b: d9 a3 e7 f9 49 8d fldenv -0x72b60619(%rbx) 11: 44 24 10 rex.R and $0x10,%al 14: 48 89 c2 mov %rax,%rdx 17: 48 89 44 24 28 mov %rax,0x28(%rsp) 1c: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 23: fc ff df 26: 48 c1 ea 03 shr $0x3,%rdx * 2a: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) <-- trapping instruction 2e: 0f 85 cf 07 00 00 jne 0x803 34: 49 83 7c 24 10 00 cmpq $0x0,0x10(%r12) 3a: 0f 84 da 05 00 00 je 0x61a

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