CVE-2023-52570

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> vfio/mdev: Fix a null-ptr-deref bug for mdev_unregister_parent()<br /> <br /> Inject fault while probing mdpy.ko, if kstrdup() of create_dir() fails in<br /> kobject_add_internal() in kobject_init_and_add() in mdev_type_add()<br /> in parent_create_sysfs_files(), it will return 0 and probe successfully.<br /> And when rmmod mdpy.ko, the mdpy_dev_exit() will call<br /> mdev_unregister_parent(), the mdev_type_remove() may traverse uninitialized<br /> parent-&gt;types[i] in parent_remove_sysfs_files(), and it will cause<br /> below null-ptr-deref.<br /> <br /> If mdev_type_add() fails, return the error code and kset_unregister()<br /> to fix the issue.<br /> <br /> general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] PREEMPT SMP KASAN<br /> KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]<br /> CPU: 2 PID: 10215 Comm: rmmod Tainted: G W N 6.6.0-rc2+ #20<br /> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014<br /> RIP: 0010:__kobject_del+0x62/0x1c0<br /> Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 51 01 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b 6b 28 48 8d 7d 10 48 89 fa 48 c1 ea 03 3c 02 00 0f 85 24 01 00 00 48 8b 75 10 48 89 df 48 8d 6b 3c e8<br /> RSP: 0018:ffff88810695fd30 EFLAGS: 00010202<br /> RAX: dffffc0000000000 RBX: ffffffffa0270268 RCX: 0000000000000000<br /> RDX: 0000000000000002 RSI: 0000000000000004 RDI: 0000000000000010<br /> RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed10233a4ef1<br /> R10: ffff888119d2778b R11: 0000000063666572 R12: 0000000000000000<br /> R13: fffffbfff404e2d4 R14: dffffc0000000000 R15: ffffffffa0271660<br /> FS: 00007fbc81981540(0000) GS:ffff888119d00000(0000) knlGS:0000000000000000<br /> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033<br /> CR2: 00007fc14a142dc0 CR3: 0000000110a62003 CR4: 0000000000770ee0<br /> DR0: ffffffff8fb0bce8 DR1: ffffffff8fb0bce9 DR2: ffffffff8fb0bcea<br /> DR3: ffffffff8fb0bceb DR6: 00000000fffe0ff0 DR7: 0000000000000600<br /> PKRU: 55555554<br /> Call Trace:<br /> <br /> ? die_addr+0x3d/0xa0<br /> ? exc_general_protection+0x144/0x220<br /> ? asm_exc_general_protection+0x22/0x30<br /> ? __kobject_del+0x62/0x1c0<br /> kobject_del+0x32/0x50<br /> parent_remove_sysfs_files+0xd6/0x170 [mdev]<br /> mdev_unregister_parent+0xfb/0x190 [mdev]<br /> ? mdev_register_parent+0x270/0x270 [mdev]<br /> ? find_module_all+0x9d/0xe0<br /> mdpy_dev_exit+0x17/0x63 [mdpy]<br /> __do_sys_delete_module.constprop.0+0x2fa/0x4b0<br /> ? module_flags+0x300/0x300<br /> ? __fput+0x4e7/0xa00<br /> do_syscall_64+0x35/0x80<br /> entry_SYSCALL_64_after_hwframe+0x46/0xb0<br /> RIP: 0033:0x7fbc813221b7<br /> Code: 73 01 c3 48 8b 0d d1 8c 2c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 b0 00 00 00 0f 05 3d 01 f0 ff ff 73 01 c3 48 8b 0d a1 8c 2c 00 f7 d8 64 89 01 48<br /> RSP: 002b:00007ffe780e0648 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0<br /> RAX: ffffffffffffffda RBX: 00007ffe780e06a8 RCX: 00007fbc813221b7<br /> RDX: 000000000000000a RSI: 0000000000000800 RDI: 000055e214df9b58<br /> RBP: 000055e214df9af0 R08: 00007ffe780df5c1 R09: 0000000000000000<br /> R10: 00007fbc8139ecc0 R11: 0000000000000206 R12: 00007ffe780e0870<br /> R13: 00007ffe780e0ed0 R14: 000055e214df9260 R15: 000055e214df9af0<br /> <br /> Modules linked in: mdpy(-) mdev vfio_iommu_type1 vfio [last unloaded: mdpy]<br /> Dumping ftrace buffer:<br /> (ftrace buffer empty)<br /> ---[ end trace 0000000000000000 ]---<br /> RIP: 0010:__kobject_del+0x62/0x1c0<br /> Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 51 01 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b 6b 28 48 8d 7d 10 48 89 fa 48 c1 ea 03 3c 02 00 0f 85 24 01 00 00 48 8b 75 10 48 89 df 48 8d 6b 3c e8<br /> RSP: 0018:ffff88810695fd30 EFLAGS: 00010202<br /> RAX: dffffc0000000000 RBX: ffffffffa0270268 RCX: 0000000000000000<br /> RDX: 0000000000000002 RSI: 0000000000000004 RDI: 0000000000000010<br /> RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed10233a4ef1<br /> R10: ffff888119d2778b R11: 0000000063666572 R12: 0000000000000000<br /> R13: fffffbfff404e2d4 R14: dffffc0000000000 R15: ffffffffa0271660<br /> FS: 00007fbc81981540(0000) GS:ffff888119d00000(000<br /> ---truncated---