cbcvebase.
CVE-2025-68751
published 2026-01-05

CVE-2025-68751: In the Linux kernel, the following vulnerability has been resolved: s390/fpu: Fix false-positive kmsan report in fpu_vstl() A false-positive kmsan report is…

PriorityP421high7.2
EPSS
0.16%
5.8th percentile
In the Linux kernel, the following vulnerability has been resolved: s390/fpu: Fix false-positive kmsan report in fpu_vstl() A false-positive kmsan report is detected when running ping command. An inline assembly instruction 'vstl' can write varied amount of bytes depending on value of 'index' argument. If 'index' > 0, 'vstl' writes at least 2 bytes. clang generates kmsan write helper call depending on inline assembly constraints. Constraints are evaluated compile-time, but value of 'index' argument is known only at runtime. clang currently generates call to __msan_instrument_asm_store with 1 byte as size. Manually call kmsan function to indicate correct amount of bytes written and fix false-positive report. This change fixes following kmsan reports: [ 36.563119] ===================================================== [ 36.563594] BUG: KMSAN: uninit-value in virtqueue_add+0x35c6/0x7c70 [ 36.563852] virtqueue_add+0x35c6/0x7c70 [ 36.564016] virtqueue_add_outbuf+0xa0/0xb0 [ 36.564266] start_xmit+0x288c/0x4a20 [ 36.564460] dev_hard_start_xmit+0x302/0x900 [ 36.564649] sch_direct_xmit+0x340/0xea0 [ 36.564894] __dev_queue_xmit+0x2e94/0x59b0 [ 36.565058] neigh_resolve_output+0x936/0xb40 [ 36.565278] __neigh_update+0x2f66/0x3a60 [ 36.565499] neigh_update+0x52/0x60 [ 36.565683] arp_process+0x1588/0x2de0 [ 36.565916] NF_HOOK+0x1da/0x240 [ 36.566087] arp_rcv+0x3e4/0x6e0 [ 36.566306] __netif_receive_skb_list_core+0x1374/0x15a0 [ 36.566527] netif_receive_skb_list_internal+0x1116/0x17d0 [ 36.566710] napi_complete_done+0x376/0x740 [ 36.566918] virtnet_poll+0x1bae/0x2910 [ 36.567130] __napi_poll+0xf4/0x830 [ 36.567294] net_rx_action+0x97c/0x1ed0 [ 36.567556] handle_softirqs+0x306/0xe10 [ 36.567731] irq_exit_rcu+0x14c/0x2e0 [ 36.567910] do_io_irq+0xd4/0x120 [ 36.568139] io_int_handler+0xc2/0xe8 [ 36.568299] arch_cpu_idle+0xb0/0xc0 [ 36.568540] arch_cpu_idle+0x76/0xc0 [ 36.568726] default_idle_call+0x40/0x70 [ 36.568953] do_idle+0x1d6/0x390 [ 36.569486] cpu_startup_entry+0x9a/0xb0

Affected

9 ranges
VendorProductVersion rangeFixed in
debianlinux< linux 6.17.13-1 (forky)linux 6.17.13-1 (forky)
linuxlinux
linuxlinux>= dcd3e1de9d17dc43dfed87a9fc814b9dec508043 < 946357a538bb47740635c25520924351d2d91544946357a538bb47740635c25520924351d2d91544
linuxlinux>= dcd3e1de9d17dc43dfed87a9fc814b9dec508043 < 13dcd6308cb8f67134ee5d5d762b2a66363c695b13dcd6308cb8f67134ee5d5d762b2a66363c695b
linuxlinux>= dcd3e1de9d17dc43dfed87a9fc814b9dec508043 < 14e4e4175b64dd9216b522f6ece8af6997d063b214e4e4175b64dd9216b522f6ece8af6997d063b2
linuxlinux_kernel>= 0 < 6.17.13-16.17.13-1
linuxlinux_kernel>= 0 < 6.17.0-19.196.17.0-19.19
linuxlinux_kernel>= 6.18.0 < 6.18.26.18.2
linuxlinux_kernel>= 6.9.0 < 6.17.136.17.13

CVSS provenance

osv7.2HIGH
vendor_ubuntu7.2HIGH
vendor_redhat3.3LOW
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