------------[ cut here ]------------
kmem_cache of name '9p-fcall-cache' already exists
WARNING: CPU: 3 PID: 6580 at mm/slab_common.c:107 kmem_cache_sanity_check mm/slab_common.c:107 [inline]
WARNING: CPU: 3 PID: 6580 at mm/slab_common.c:107 __kmem_cache_create_args+0xb0/0x3c0 mm/slab_common.c:294
Modules linked in:
CPU: 3 UID: 0 PID: 6580 Comm: syz.0.327 Not tainted 6.12.0-rc1-syzkaller-00330-gfc20a3e57247 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:kmem_cache_sanity_check mm/slab_common.c:107 [inline]
RIP: 0010:__kmem_cache_create_args+0xb0/0x3c0 mm/slab_common.c:294
Code: 98 48 3d f0 d5 31 8e 74 25 48 8b 7b 60 48 89 ee e8 85 5c 42 09 85 c0 75 e0 90 48 c7 c7 20 0c 7b 8d 48 89 ee e8 11 18 7e ff 90 <0f> 0b 90 90 be 20 00 00 00 48 89 ef e8 0f 5e 42 09 48 85 c0 0f 85
RSP: 0018:ffffc90005587900 EFLAGS: 00010282
RAX: 0000000000000000 RBX: ffff88802557b7c0 RCX: ffffc900079f2000
RDX: 0000000000040000 RSI: ffffffff814e71b6 RDI: 0000000000000001
RBP: ffffffff8cc38fa0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000020018 R14: ffffc900055879f0 R15: 0000000000020018
FS:  00007fecf45de6c0(0000) GS:ffff88806a900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000004d1d0000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 kmem_cache_create_usercopy include/linux/slab.h:361 [inline]
 p9_client_create+0xebd/0x11b0 net/9p/client.c:1042
 v9fs_session_init+0x1f8/0x1a80 fs/9p/v9fs.c:410
 v9fs_mount+0xc6/0xa50 fs/9p/vfs_super.c:122
 legacy_get_tree+0x109/0x220 fs/fs_context.c:662
 vfs_get_tree+0x8f/0x380 fs/super.c:1800
 do_new_mount fs/namespace.c:3507 [inline]
 path_mount+0x14e6/0x1f20 fs/namespace.c:3834
 do_mount fs/namespace.c:3847 [inline]
 __do_sys_mount fs/namespace.c:4055 [inline]
 __se_sys_mount fs/namespace.c:4032 [inline]
 __x64_sys_mount+0x294/0x320 fs/namespace.c:4032
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fecf4b7dff9
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:00007fecf45de038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fecf4d36058 RCX: 00007fecf4b7dff9
RDX: 0000000020000180 RSI: 0000000020000000 RDI: 0000000000000000
RBP: 00007fecf4bf0296 R08: 00000000200002c0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fecf4d36058 R15: 00007ffc2c589218
 </TASK>