R13: 00007f9c678d3fac R14: 00007f9c678d3fa0 R15: 00007f9c678d3fa0 kobject_add_internal failed for md0 with -EEXIST, don't try to register things with the same name in the same directory. ------------[ cut here ]------------ WARNING: CPU: 0 PID: 5095 at block/genhd.c:554 device_add_disk+0x8d6/0xde0 block/genhd.c:552 Modules linked in: CPU: 0 PID: 5095 Comm: syz.2.713 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:device_add_disk+0x8d6/0xde0 block/genhd.c:554 Code: 04 48 89 d8 48 c1 e8 03 42 0f b6 04 30 84 c0 0f 85 8f 03 00 00 8b 33 48 c7 c7 80 f5 90 8c e8 f1 3d 37 00 eb 05 e8 ca 3f a6 fd <0f> 0b 41 bd 01 00 00 00 44 89 e8 48 83 c4 50 5b 41 5c 41 5d 41 5e RSP: 0018:ffffc90002f8fa00 EFLAGS: 00010293 RAX: ffffffff83d2d4d6 RBX: ffff888070ad4c00 RCX: ffff888021483b80 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 0000000000000103 RBP: 0000000000000009 R08: ffff8880170ba3bb R09: 1ffff11002e17477 R10: dffffc0000000000 R11: ffffed1002e17478 R12: 1ffff11002e17477 R13: 1ffff1100e15a994 R14: dffffc0000000000 R15: ffff8880170ba380 FS: 0000555581f5e500(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000559317363168 CR3: 000000005b9a7000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: add_disk include/linux/genhd.h:200 [inline] md_alloc+0x80e/0xc10 drivers/md/md.c:5789 add_named_array+0x1bd/0x290 drivers/md/md.c:-1 param_attr_store+0x20a/0x300 kernel/params.c:585 module_attr_store+0x5b/0x80 kernel/params.c:905 kernfs_fop_write_iter+0x3a8/0x500 fs/kernfs/file.c:296 call_write_iter include/linux/fs.h:2179 [inline] new_sync_write fs/read_write.c:507 [inline] vfs_write+0x748/0xd70 fs/read_write.c:594 ksys_write+0x153/0x260 fs/read_write.c:647 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f9c6764c159 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffdb2801c98 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f9c678d3fa0 RCX: 00007f9c6764c159 RDX: 0000000000000003 RSI: 0000200000000280 RDI: 0000000000000003 RBP: 00007f9c676e306b R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f9c678d3fac R14: 00007f9c678d3fa0 R15: 00007f9c678d3fa0