CVE: CVE-2022-50851
Published: 2025-12-30
Description: In the Linux kernel, the following vulnerability has been resolved:

vhost_vdpa: fix the crash in unmap a large memory

While testing in vIOMMU, sometimes Guest will unmap very large memory,
which will cause the crash. To fix this, add a new function
vhost_vdpa_general_unmap(). This function will only unmap the memory
that saved in iotlb.

Call Trace:
[  647.820144] ------------[ cut here ]------------
[  647.820848] kernel BUG at drivers/iommu/intel/iommu.c:1174!
[  647.821486] invalid opcode: 0000 [#1] PREEMPT SMP PTI
[  647.822082] CPU: 10 PID: 1181 Comm: qemu-system-x86 Not tainted 6.0.0-rc1home_lulu_2452_lulu7_vhost+ #62
[  647.823139] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.15.0-29-g6a62e0cb0dfe-prebuilt.qem4
[  647.824365] RIP: 0010:domain_unmap+0x48/0x110
[  647.825424] Code: 48 89 fb 8d 4c f6 1e 39 c1 0f 4f c8 83 e9 0c 83 f9 3f 7f 18 48 89 e8 48 d3 e8 48 85 c0 75 59
[  647.828064] RSP: 0018:ffffae5340c0bbf0 EFLAGS: 00010202
[  647.828973] RAX: [PII_REDACTED] RBX: ffff921793d10540 RCX:[PII_REDACTED]00001b
[  647.830083] RDX:[PII_REDACTED]0000ff RSI: [PII_REDACTED] RDI: ffff921793d10540
[  647.831214] RBP:[PII_REDACTED]fc0100 R08: ffffae5340c0bcd0 R09: [PII_REDACTED]
[  647.832388] R10: 0000007fc0100000 R11: [PII_REDACTED] R12:[PII_REDACTED]0000ff
[  647.833668] R13: ffffae5340c0bcd0 R14: ffff921793d10590 R15: [PII_REDACTED]
[  647.834782] FS:  00007f772ec90640(0000) GS:ffff921ce7a80000(0000) knlGS:[PII_REDACTED]
[  647.836004] CS:  0010 DS: 0000 ES: 0000 CR0: [PII_REDACTED]
[  647.836990] CR2: 00007f02c27a3a20 CR3:[PII_REDACTED]b0c006 CR4:[PII_REDACTED]372ee0
[  647.838107] DR0: [PII_REDACTED] DR1: [PII_REDACTED] DR2: [PII_REDACTED]
[  647.839283] DR3: [PII_REDACTED] DR6: 00000000fffe0ff0 DR7: [PII_REDACTED]
[  647.840666] Call Trace:
[  647.841437]  <TASK>
[  647.842107]  intel_iommu_unmap_pages+0x93/0x140
[  647.843112]  __iommu_unmap+0x91/0x1b0
[  647.844003]  iommu_unmap+0x6a/0x95
[  647.844885]  vhost_vdpa_unmap+0x1de/0x1f0 [vhost_vdpa]
[  647.845985]  vhost_vdpa_process_iotlb_msg+0xf0/0x90b [vhost_vdpa]
[  647.847235]  ? _raw_spin_unlock+0x15/0x30
[  647.848181]  ? _copy_from_iter+0x8c/0x580
[  647.849137]  vhost_chr_write_iter+0xb3/0x430 [vhost]
[  647.850126]  vfs_write+0x1e4/0x3a0
[  647.850897]  ksys_write+0x53/0xd0
[  647.851688]  do_syscall_64+0x3a/0x90
[  647.852508]  entry_SYSCALL_64_after_hwframe+0x63/0xcd
[  647.853457] RIP: 0033:0x7f7734ef9f4f
[  647.854408] Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 29 76 f8 ff 48 8b 54 24 18 48 8b 74 24 10 41 89 c8
[  647.857217] RSP: 002b:00007f772ec8f040 EFLAGS: 00000293 ORIG_RAX: [PII_REDACTED]
[  647.858486] RAX: ffffffffffffffda RBX: 00000000fef00000 RCX: 00007f7734ef9f4f
[  647.859713] RDX: [PII_REDACTED] RSI: 00007f772ec8f090 RDI: [PII_REDACTED]
[  647.860942] RBP: 00007f772ec8f1a0 R08: [PII_REDACTED] R09: [PII_REDACTED]
[  647.862206] R10: [PII_REDACTED] R11: [PII_REDACTED] R12: [PII_REDACTED]
[  647.863446] R13: [PII_REDACTED] R14: [PII_REDACTED] R15: ffffffff01100000
[  647.864692]  </TASK>
[  647.865458] Modules linked in: rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd grace fscache netfs v]
[  647.874688] ---[ end trace [PII_REDACTED] ]---
References: https://git.kernel.org/stable/c/26b7400c89b81e2f6de4f224ba1fdf06f293de31; https://git.kernel.org/stable/c/8b258a31c2e8d4d4e42be70a7c6ca35a5afbff0d; https://git.kernel.org/stable/c/e794070af224ade46db368271896b2685ff4f96b