CVE-2024-45005
Publication date:
04/09/2024
In the Linux kernel, the following vulnerability has been resolved:<br />
<br />
KVM: s390: fix validity interception issue when gisa is switched off<br />
<br />
We might run into a SIE validity if gisa has been disabled either via using<br />
kernel parameter "kvm.use_gisa=0" or by setting the related sysfs<br />
attribute to N (echo N >/sys/module/kvm/parameters/use_gisa).<br />
<br />
The validity is caused by an invalid value in the SIE control block&#39;s<br />
gisa designation. That happens because we pass the uninitialized gisa<br />
origin to virt_to_phys() before writing it to the gisa designation.<br />
<br />
To fix this we return 0 in kvm_s390_get_gisa_desc() if the origin is 0.<br />
kvm_s390_get_gisa_desc() is used to determine which gisa designation to<br />
set in the SIE control block. A value of 0 in the gisa designation disables<br />
gisa usage.<br />
<br />
The issue surfaces in the host kernel with the following kernel message as<br />
soon a new kvm guest start is attemted.<br />
<br />
kvm: unhandled validity intercept 0x1011<br />
WARNING: CPU: 0 PID: 781237 at arch/s390/kvm/intercept.c:101 kvm_handle_sie_intercept+0x42e/0x4d0 [kvm]<br />
Modules linked in: vhost_net tap tun xt_CHECKSUM xt_MASQUERADE xt_conntrack ipt_REJECT xt_tcpudp nft_compat x_tables nf_nat_tftp nf_conntrack_tftp vfio_pci_core irqbypass vhost_vsock vmw_vsock_virtio_transport_common vsock vhost vhost_iotlb kvm nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ip_set nf_tables sunrpc mlx5_ib ib_uverbs ib_core mlx5_core uvdevice s390_trng eadm_sch vfio_ccw zcrypt_cex4 mdev vfio_iommu_type1 vfio sch_fq_codel drm i2c_core loop drm_panel_orientation_quirks configfs nfnetlink lcs ctcm fsm dm_service_time ghash_s390 prng chacha_s390 libchacha aes_s390 des_s390 libdes sha3_512_s390 sha3_256_s390 sha512_s390 sha256_s390 sha1_s390 sha_common dm_mirror dm_region_hash dm_log zfcp scsi_transport_fc scsi_dh_rdac scsi_dh_emc scsi_dh_alua pkey zcrypt dm_multipath rng_core autofs4 [last unloaded: vfio_pci]<br />
CPU: 0 PID: 781237 Comm: CPU 0/KVM Not tainted 6.10.0-08682-gcad9f11498ea #6<br />
Hardware name: IBM 3931 A01 701 (LPAR)<br />
Krnl PSW : 0704c00180000000 000003d93deb0122 (kvm_handle_sie_intercept+0x432/0x4d0 [kvm])<br />
R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:0 PM:0 RI:0 EA:3<br />
Krnl GPRS: 000003d900000027 000003d900000023 0000000000000028 000002cd00000000<br />
000002d063a00900 00000359c6daf708 00000000000bebb5 0000000000001eff<br />
000002cfd82e9000 000002cfd80bc000 0000000000001011 000003d93deda412<br />
000003ff8962df98 000003d93de77ce0 000003d93deb011e 00000359c6daf960<br />
Krnl Code: 000003d93deb0112: c020fffe7259 larl %r2,000003d93de7e5c4<br />
000003d93deb0118: c0e53fa8beac brasl %r14,000003d9bd3c7e70<br />
#000003d93deb011e: af000000 mc 0,0<br />
>000003d93deb0122: a728ffea lhi %r2,-22<br />
000003d93deb0126: a7f4fe24 brc 15,000003d93deafd6e<br />
000003d93deb012a: 9101f0b0 tm 176(%r15),1<br />
000003d93deb012e: a774fe48 brc 7,000003d93deafdbe<br />
000003d93deb0132: 40a0f0ae sth %r10,174(%r15)<br />
Call Trace:<br />
[] kvm_handle_sie_intercept+0x432/0x4d0 [kvm]<br />
([] kvm_handle_sie_intercept+0x42e/0x4d0 [kvm])<br />
[] vcpu_post_run+0x1d0/0x3b0 [kvm]<br />
[] __vcpu_run+0xea/0x2d0 [kvm]<br />
[] kvm_arch_vcpu_ioctl_run+0x16a/0x430 [kvm]<br />
[] kvm_vcpu_ioctl+0x190/0x7c0 [kvm]<br />
[] vfs_ioctl+0x2e/0x70<br />
[] __s390x_sys_ioctl+0xc2/0xd0<br />
[] __do_syscall+0x1f2/0x2e0<br />
[] system_call+0x70/0x98<br />
Last Breaking-Event-Address:<br />
[] __warn_printk+0xe8/0xf0
Severity CVSS v4.0: Pending analysis
Last modification:
09/10/2024