ext4_page_mkwrite+0x35e/0x1760 fs/ext4/inode.c:6577 do_page_mkwrite+0x174/0x380 mm/memory.c:3378 do_shared_fault mm/memory.c:5666 [inline] do_fault mm/memory.c:5728 [inline] do_pte_missing mm/memory.c:4251 [inline] handle_pte_fault mm/memory.c:6069 [inline] __handle_mm_fault+0x3829/0x5490 mm/memory.c:6212 handle_mm_fault+0x589/0xd10 mm/memory.c:6381 do_user_addr_fault+0x60c/0x1370 arch/x86/mm/fault.c:1336 ------------[ cut here ]------------ kernel BUG at mm/filemap.c:3442! Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI CPU: 1 UID: 0 PID: 9340 Comm: syz.3.642 Not tainted 6.16.0-rc6-syzkaller-00002-g155a3c003e55 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:filemap_fault+0x1847/0x26c0 mm/filemap.c:3442 Code: 00 e9 d2 ec ff ff 48 8b 7c 24 28 e8 b3 36 2e 00 e9 79 f3 ff ff e8 79 52 c8 ff 48 c7 c6 e0 20 b9 8b 48 89 df e8 3a a0 10 00 90 <0f> 0b e8 62 52 c8 ff 48 c7 c6 e0 16 b9 8b 48 89 df e8 23 a0 10 00 RSP: 0018:ffffc900035275b8 EFLAGS: 00010246 RAX: 0000000000080000 RBX: ffffea0001eff480 RCX: ffffc9000d8e5000 RDX: 0000000000080000 RSI: ffffffff81f39f66 RDI: ffff88802d2a2244 RBP: ffffc900035277e8 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff90a9a357 R11: 1ffffffff1cb9fa9 R12: ffff8880241fcd78 R13: 0000000000000001 R14: 0000000000000001 R15: 0000000000000000 FS: 00007f5877f7e6c0(0000) GS:ffff88812481a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffc02810068 CR3: 0000000079e92000 CR4: 0000000000350ef0 Call Trace: __do_fault+0x10d/0x490 mm/memory.c:5169 do_read_fault mm/memory.c:5590 [inline] do_fault mm/memory.c:5724 [inline] do_pte_missing mm/memory.c:4251 [inline] handle_pte_fault mm/memory.c:6069 [inline] __handle_mm_fault+0x3c2a/0x5490 mm/memory.c:6212 handle_mm_fault+0x589/0xd10 mm/memory.c:6381 do_user_addr_fault+0x7a6/0x1370 arch/x86/mm/fault.c:1387 handle_page_fault arch/x86/mm/fault.c:1476 [inline] exc_page_fault+0x5c/0xb0 arch/x86/mm/fault.c:1532 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0010:copy_user_generic arch/x86/include/asm/uaccess_64.h:126 [inline] RIP: 0010:raw_copy_from_user arch/x86/include/asm/uaccess_64.h:141 [inline] RIP: 0010:_inline_copy_from_user include/linux/uaccess.h:178 [inline] RIP: 0010:_copy_from_user+0x93/0xd0 lib/usercopy.c:18 Code: 02 e2 fc 89 ee 4c 89 ef 48 b8 00 f0 ff ff ff 7f 00 00 48 39 c3 48 0f 47 d8 e8 79 ee 47 fd 0f 01 cb 4c 89 ef 48 89 de 48 89 e9 a4 0f 1f 00 49 89 cc 48 89 cb 0f 01 ca 31 ff 48 89 ce e8 95 fd RSP: 0018:ffffc90003527a80 EFLAGS: 00050246 RAX: 0000000000000001 RBX: 0000200000001898 RCX: 0000000000000001 RDX: ffffed1004cabcbc RSI: 0000200000001898 RDI: ffff88802655e5d8 RBP: 0000000000000001 R08: 0000000000000001 R09: ffffed1004cabcbb R10: ffff88802655e5d8 R11: 0000000000000001 R12: 0000000000000000 R13: ffff88802655e5d8 R14: dffffc0000000000 R15: 0000200000001898 copy_from_user include/linux/uaccess.h:212 [inline] snd_rawmidi_kernel_write1+0x50a/0x8a0 sound/core/rawmidi.c:1560 snd_rawmidi_write+0x26e/0xc10 sound/core/rawmidi.c:1629 do_loop_readv_writev fs/read_write.c:850 [inline] do_loop_readv_writev fs/read_write.c:835 [inline] vfs_writev+0x5df/0xde0 fs/read_write.c:1059 do_writev+0x28c/0x340 fs/read_write.c:1103 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f587718e929 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f5877f7e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 00007f58773b5fa0 RCX: 00007f587718e929 RDX: 0000000000000002 RSI: 0000200000000840 RDI: 0000000000000005 RBP: 00007f5877210b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f58773b5fa0 R15: 00007ffc94c5b168 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:filemap_fault+0x1847/0x26c0 mm/filemap.c:3442 Code: 00 e9 d2 ec ff ff 48 8b 7c 24 28 e8 b3 36 2e 00 e9 79 f3 ff ff e8 79 52 c8 ff 48 c7 c6 e0 20 b9 8b 48 89 df e8 3a a0 10 00 90 <0f> 0b e8 62 52 c8 ff 48 c7 c6 e0 16 b9 8b 48 89 df e8 23 a0 10 00 RSP: 0018:ffffc900035275b8 EFLAGS: 00010246 RAX: 0000000000080000 RBX: ffffea0001eff480 RCX: ffffc9000d8e5000 RDX: 0000000000080000 RSI: ffffffff81f39f66 RDI: ffff88802d2a2244 RBP: ffffc900035277e8 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff90a9a357 R11: 1ffffffff1cb9fa9 R12: ffff8880241fcd78 R13: 0000000000000001 R14: 0000000000000001 R15: 0000000000000000 FS: 00007f5877f7e6c0(0000) GS:ffff88812481a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffc02810068 CR3: 0000000079e92000 CR4: 0000000000350ef0 ---------------- Code disassembly (best guess): 0: 02 e2 add %dl,%ah 2: fc cld 3: 89 ee mov %ebp,%esi 5: 4c 89 ef mov %r13,%rdi 8: 48 b8 00 f0 ff ff ff movabs $0x7ffffffff000,%rax f: 7f 00 00 12: 48 39 c3 cmp %rax,%rbx 15: 48 0f 47 d8 cmova %rax,%rbx 19: e8 79 ee 47 fd call 0xfd47ee97 1e: 0f 01 cb stac 21: 4c 89 ef mov %r13,%rdi 24: 48 89 de mov %rbx,%rsi 27: 48 89 e9 mov %rbp,%rcx * 2a: f3 a4 rep movsb %ds:(%rsi),%es:(%rdi) <-- trapping instruction 2c: 0f 1f 00 nopl (%rax) 2f: 49 89 cc mov %rcx,%r12 32: 48 89 cb mov %rcx,%rbx 35: 0f 01 ca clac 38: 31 ff xor %edi,%edi 3a: 48 89 ce mov %rcx,%rsi 3d: e8 .byte 0xe8 3e: 95 xchg %eax,%ebp 3f: fd std