wireguard-linux/arch/s390, branch update-toolchain

s390/uv: Panic for set and remove shared access UVC errors

2024-08-07T11:04:43Z

The return value uv_set_shared() and uv_remove_shared() (which are wrappers around the share() function) is not always checked. The system integrity of a protected guest depends on the Share and Unshare UVCs being successful. This means that any caller that fails to check the return value will compromise the security of the protected guest. No code path that would lead to such violation of the security guarantees is currently exercised, since all the areas that are shared never get unshared during the lifetime of the system. This might change and become an issue in the future. The Share and Unshare UVCs can only fail in case of hypervisor misbehaviour (either a bug or malicious behaviour). In such cases there is no reasonable way forward, and the system needs to panic. This patch replaces the return at the end of the share() function with a panic, to guarantee system integrity. Fixes: 5abb9351dfd9 ("s390/uv: introduce guest side ultravisor code") Signed-off-by: Claudio Imbrenda Reviewed-by: Christian Borntraeger Reviewed-by: Steffen Eiden Reviewed-by: Janosch Frank Link: https://lore.kernel.org/r/20240801112548.85303-1-imbrenda@linux.ibm.com Message-ID: <20240801112548.85303-1-imbrenda@linux.ibm.com> [frankja@linux.ibm.com: Fixed up patch subject] Signed-off-by: Janosch Frank

KVM: s390: fix validity interception issue when gisa is switched off

2024-08-06T06:33:18Z

We might run into a SIE validity if gisa has been disabled either via using kernel parameter "kvm.use_gisa=0" or by setting the related sysfs attribute to N (echo N >/sys/module/kvm/parameters/use_gisa). The validity is caused by an invalid value in the SIE control block's gisa designation. That happens because we pass the uninitialized gisa origin to virt_to_phys() before writing it to the gisa designation. To fix this we return 0 in kvm_s390_get_gisa_desc() if the origin is 0. kvm_s390_get_gisa_desc() is used to determine which gisa designation to set in the SIE control block. A value of 0 in the gisa designation disables gisa usage. The issue surfaces in the host kernel with the following kernel message as soon a new kvm guest start is attemted. kvm: unhandled validity intercept 0x1011 WARNING: CPU: 0 PID: 781237 at arch/s390/kvm/intercept.c:101 kvm_handle_sie_intercept+0x42e/0x4d0 [kvm] 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] CPU: 0 PID: 781237 Comm: CPU 0/KVM Not tainted 6.10.0-08682-gcad9f11498ea #6 Hardware name: IBM 3931 A01 701 (LPAR) Krnl PSW : 0704c00180000000 000003d93deb0122 (kvm_handle_sie_intercept+0x432/0x4d0 [kvm]) 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 Krnl GPRS: 000003d900000027 000003d900000023 0000000000000028 000002cd00000000 000002d063a00900 00000359c6daf708 00000000000bebb5 0000000000001eff 000002cfd82e9000 000002cfd80bc000 0000000000001011 000003d93deda412 000003ff8962df98 000003d93de77ce0 000003d93deb011e 00000359c6daf960 Krnl Code: 000003d93deb0112: c020fffe7259 larl %r2,000003d93de7e5c4 000003d93deb0118: c0e53fa8beac brasl %r14,000003d9bd3c7e70 #000003d93deb011e: af000000 mc 0,0 >000003d93deb0122: a728ffea lhi %r2,-22 000003d93deb0126: a7f4fe24 brc 15,000003d93deafd6e 000003d93deb012a: 9101f0b0 tm 176(%r15),1 000003d93deb012e: a774fe48 brc 7,000003d93deafdbe 000003d93deb0132: 40a0f0ae sth %r10,174(%r15) Call Trace: [<000003d93deb0122>] kvm_handle_sie_intercept+0x432/0x4d0 [kvm] ([<000003d93deb011e>] kvm_handle_sie_intercept+0x42e/0x4d0 [kvm]) [<000003d93deacc10>] vcpu_post_run+0x1d0/0x3b0 [kvm] [<000003d93deaceda>] __vcpu_run+0xea/0x2d0 [kvm] [<000003d93dead9da>] kvm_arch_vcpu_ioctl_run+0x16a/0x430 [kvm] [<000003d93de93ee0>] kvm_vcpu_ioctl+0x190/0x7c0 [kvm] [<000003d9bd728b4e>] vfs_ioctl+0x2e/0x70 [<000003d9bd72a092>] __s390x_sys_ioctl+0xc2/0xd0 [<000003d9be0e9222>] __do_syscall+0x1f2/0x2e0 [<000003d9be0f9a90>] system_call+0x70/0x98 Last Breaking-Event-Address: [<000003d9bd3c7f58>] __warn_printk+0xe8/0xf0 Cc: stable@vger.kernel.org Reported-by: Christian Borntraeger Fixes: fe0ef0030463 ("KVM: s390: sort out physical vs virtual pointers usage") Signed-off-by: Michael Mueller Tested-by: Christian Borntraeger Reviewed-by: Janosch Frank Link: https://lore.kernel.org/r/20240801123109.2782155-1-mimu@linux.ibm.com Message-ID: <20240801123109.2782155-1-mimu@linux.ibm.com> Signed-off-by: Janosch Frank

s390: Keep inittext section writable

2024-07-31T14:30:20Z

There is no added security by making the inittext section non-writable, however it does split part of the kernel mapping into 4K mappings instead of 1M mappings: ---[ Kernel Image Start ]--- 0x000003ffe0000000-0x000003ffe0e00000 14M PMD RO X 0x000003ffe0e00000-0x000003ffe0ec7000 796K PTE RO X 0x000003ffe0ec7000-0x000003ffe0f00000 228K PTE RO NX 0x000003ffe0f00000-0x000003ffe1300000 4M PMD RO NX 0x000003ffe1300000-0x000003ffe1353000 332K PTE RO NX 0x000003ffe1353000-0x000003ffe1400000 692K PTE RW NX 0x000003ffe1400000-0x000003ffe1500000 1M PMD RW NX 0x000003ffe1500000-0x000003ffe1700000 2M PTE RW NX <--- 0x000003ffe1700000-0x000003ffe1800000 1M PMD RW NX 0x000003ffe1800000-0x000003ffe187e000 504K PTE RW NX ---[ Kernel Image End ]--- Keep the inittext writable and enable instruction execution protection (aka noexec) later to prevent this. This also allows to use the generic free_initmem() implementation. ---[ Kernel Image Start ]--- 0x000003ffe0000000-0x000003ffe0e00000 14M PMD RO X 0x000003ffe0e00000-0x000003ffe0ec7000 796K PTE RO X 0x000003ffe0ec7000-0x000003ffe0f00000 228K PTE RO NX 0x000003ffe0f00000-0x000003ffe1300000 4M PMD RO NX 0x000003ffe1300000-0x000003ffe1353000 332K PTE RO NX 0x000003ffe1353000-0x000003ffe1400000 692K PTE RW NX 0x000003ffe1400000-0x000003ffe1800000 4M PMD RW NX <--- 0x000003ffe1800000-0x000003ffe187e000 504K PTE RW NX ---[ Kernel Image End ]--- Reviewed-by: Alexander Gordeev Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/vmlinux.lds.S: Move ro_after_init section behind rodata section

2024-07-31T14:30:20Z

The .data.rel.ro and .got section were added between the rodata and ro_after_init data section, which adds an RW mapping in between all RO mapping of the kernel image: ---[ Kernel Image Start ]--- 0x000003ffe0000000-0x000003ffe0e00000 14M PMD RO X 0x000003ffe0e00000-0x000003ffe0ec7000 796K PTE RO X 0x000003ffe0ec7000-0x000003ffe0f00000 228K PTE RO NX 0x000003ffe0f00000-0x000003ffe1300000 4M PMD RO NX 0x000003ffe1300000-0x000003ffe1331000 196K PTE RO NX 0x000003ffe1331000-0x000003ffe13b3000 520K PTE RW NX <--- 0x000003ffe13b3000-0x000003ffe13d5000 136K PTE RO NX 0x000003ffe13d5000-0x000003ffe1400000 172K PTE RW NX 0x000003ffe1400000-0x000003ffe1500000 1M PMD RW NX 0x000003ffe1500000-0x000003ffe1700000 2M PTE RW NX 0x000003ffe1700000-0x000003ffe1800000 1M PMD RW NX 0x000003ffe1800000-0x000003ffe187e000 504K PTE RW NX ---[ Kernel Image End ]--- Move the ro_after_init data section again right behind the rodata section to prevent interleaving RO and RW mappings: ---[ Kernel Image Start ]--- 0x000003ffe0000000-0x000003ffe0e00000 14M PMD RO X 0x000003ffe0e00000-0x000003ffe0ec7000 796K PTE RO X 0x000003ffe0ec7000-0x000003ffe0f00000 228K PTE RO NX 0x000003ffe0f00000-0x000003ffe1300000 4M PMD RO NX 0x000003ffe1300000-0x000003ffe1353000 332K PTE RO NX 0x000003ffe1353000-0x000003ffe1400000 692K PTE RW NX 0x000003ffe1400000-0x000003ffe1500000 1M PMD RW NX 0x000003ffe1500000-0x000003ffe1700000 2M PTE RW NX 0x000003ffe1700000-0x000003ffe1800000 1M PMD RW NX 0x000003ffe1800000-0x000003ffe187e000 504K PTE RW NX ---[ Kernel Image End ]--- Reviewed-by: Alexander Gordeev Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/mm: Get rid of RELOC_HIDE()

2024-07-31T14:30:20Z

Since __va(0) does not translate to NULL anymore remove RELOC_HIDE() which was only added to get rid of a compile warning with clang W=1: arch/s390/mm/vmem.c:666:36: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 666 | __set_memory_4k(__va(0), __va(0) + ident_map_size); | ~~~~~~~ ^ Reviewed-by: Alexander Gordeev Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/mm/ptdump: Improve sorting of markers

2024-07-31T14:30:20Z

Use the sort() from lib/sort.c to sort markers instead of the private implementation. The current implementation does not sort markers properly if they have to be moved downwards: ---[ Real Memory Copy Area Start ]--- 0x0000035b903ff000-0x0000035b90400000 4K PTE I ---[ vmalloc Area Start ]--- ---[ Real Memory Copy Area End ]--- Add a new member to each marker which indicates if a marker is start of an area. If addresses of areas are equal consider an address which defines the start of an area higher than the address which defines the end of an area. In result the output is sorted as intended: ---[ Real Memory Copy Area Start ]--- 0x0000019cedcff000-0x0000019cedd00000 4K PTE I ---[ Real Memory Copy Area End ]--- ---[ vmalloc Area Start ]--- Reviewed-by: Alexander Gordeev Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/mm/ptdump: Add support for relocated lowcore mapping

2024-07-31T14:30:20Z

The page table dumper contains a hard coded assumption that the first mapped area starts at address zero. With a relocated lowcore this is not true anymore. Subsequently the first entry (lowcore) is printed as if it would contain everything from address zero until the end of the location of the lowcore area. Fix this by adding a single "Kernel Virtual Address Space" entry, which always starts at address zero. It ends when the lowcore area starts which is either address zero, or its relocated address. Reviewed-by: Sven Schnelle Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/mm/ptdump: Fix handling of identity mapping area

2024-07-31T14:30:20Z

Since virtual and real addresses are not the same anymore the assumption that the kernel image is contained within the identity mapping is also not true anymore. Fix this by adding two explicit areas and at the correct locations: one for the 8kb lowcore area, and one for the identity mapping. Fixes: c98d2ecae08f ("s390/mm: Uncouple physical vs virtual address spaces") Reviewed-by: Alexander Gordeev Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/alternatives: Remove unused empty header file

2024-07-31T14:30:20Z

Remove the unused and empty arch/s390/kernel/alternative.h header file which was added by mistake. Fixes: 5ade5be4edf8 ("s390: Add infrastructure to patch lowcore accesses") Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/fpu: Re-add exception handling in load_fpu_state()

2024-07-31T14:30:20Z

With the recent rewrite of the fpu code exception handling for the lfpc instruction within load_fpu_state() was erroneously removed. Add it again to prevent that loading invalid floating point register values cause an unhandled specification exception. Fixes: 8c09871a950a ("s390/fpu: limit save and restore to used registers") Cc: stable@vger.kernel.org Reported-by: Aristeu Rozanski Tested-by: Aristeu Rozanski Reviewed-by: Vasily Gorbik Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik