{"id":"DEBIAN-CVE-2026-23345","details":"In the Linux kernel, the following vulnerability has been resolved:  arm64: gcs: Do not set PTE_SHARED on GCS mappings if FEAT_LPA2 is enabled  When FEAT_LPA2 is enabled, bits 8-9 of the PTE replace the shareability attribute with bits 50-51 of the output address. The _PAGE_GCS{,_RO} definitions include the PTE_SHARED bits as 0b11 (this matches the other _PAGE_* definitions) but using this macro directly leads to the following panic when enabling GCS on a system/model with LPA2:    Unable to handle kernel paging request at virtual address fffff1ffc32d8008   Mem abort info:     ESR = 0x0000000096000004     EC = 0x25: DABT (current EL), IL = 32 bits     SET = 0, FnV = 0     EA = 0, S1PTW = 0     FSC = 0x04: level 0 translation fault   Data abort info:     ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000     CM = 0, WnR = 0, TnD = 0, TagAccess = 0     GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0   swapper pgtable: 4k pages, 52-bit VAs, pgdp=0000000060f4d000   [fffff1ffc32d8008] pgd=100000006184b003, p4d=0000000000000000   Internal error: Oops: 0000000096000004 [#1]  SMP   CPU: 0 UID: 0 PID: 513 Comm: gcs_write_fault Tainted: G   M                7.0.0-rc1 #1 PREEMPT   Tainted: [M]=MACHINE_CHECK   Hardware name: QEMU QEMU Virtual Machine, BIOS 2025.02-8+deb13u1 11/08/2025   pstate: 03402005 (nzcv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--)   pc : zap_huge_pmd+0x168/0x468   lr : zap_huge_pmd+0x2c/0x468   sp : ffff800080beb660   x29: ffff800080beb660 x28: fff00000c2058180 x27: ffff800080beb898   x26: fff00000c2058180 x25: ffff800080beb820 x24: 00c800010b600f41   x23: ffffc1ffc30af1a8 x22: fff00000c2058180 x21: 0000ffff8dc00000   x20: fff00000c2bc6370 x19: ffff800080beb898 x18: ffff800080bebb60   x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000007   x14: 000000000000000a x13: 0000aaaacbbbffff x12: 0000000000000000   x11: 0000ffff8ddfffff x10: 00000000000001fe x9 : 0000ffff8ddfffff   x8 : 0000ffff8de00000 x7 : 0000ffff8da00000 x6 : fff00000c2bc6370   x5 : 0000ffff8da00000 x4 : 000000010b600000 x3 : ffffc1ffc0000000   x2 : fff00000c2058180 x1 : fffff1ffc32d8000 x0 : 000000c00010b600   Call trace:    zap_huge_pmd+0x168/0x468 (P)    unmap_page_range+0xd70/0x1560    unmap_single_vma+0x48/0x80    unmap_vmas+0x90/0x180    unmap_region+0x88/0xe4    vms_complete_munmap_vmas+0xf8/0x1e0    do_vmi_align_munmap+0x158/0x180    do_vmi_munmap+0xac/0x160    __vm_munmap+0xb0/0x138    vm_munmap+0x14/0x20    gcs_free+0x70/0x80    mm_release+0x1c/0xc8    exit_mm_release+0x28/0x38    do_exit+0x190/0x8ec    do_group_exit+0x34/0x90    get_signal+0x794/0x858    arch_do_signal_or_restart+0x11c/0x3e0    exit_to_user_mode_loop+0x10c/0x17c    el0_da+0x8c/0x9c    el0t_64_sync_handler+0xd0/0xf0    el0t_64_sync+0x198/0x19c   Code: aa1603e2 d34cfc00 cb813001 8b011861 (f9400420)  Similarly to how the kernel handles protection_map[], use a gcs_page_prot variable to store the protection bits and clear PTE_SHARED if LPA2 is enabled.  Also remove the unused PAGE_GCS{,_RO} macros.","modified":"2026-09-14T17:02:55.901102228Z","published":"2026-03-25T11:16:32.610Z","upstream":["CVE-2026-23345"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-23345"}],"affected":[{"package":{"name":"linux","ecosystem":"Debian:14","purl":"pkg:deb/debian/linux?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.19.8-1"}]}],"versions":["6.12.100-1","6.12.101-1","6.12.105-1","6.12.107-1","6.12.38-1","6.12.41-1","6.12.43-1","6.12.43-1~bpo12+1","6.12.48-1","6.12.57-1","6.12.57-1~bpo12+1","6.12.63-1","6.12.63-1~bpo12+1","6.12.69-1","6.12.69-1~bpo12+1","6.12.73-1","6.12.73-1~bpo12+1","6.12.74-1","6.12.74-2","6.12.74-2~bpo12+1","6.12.85-1","6.12.85-1~bpo12+1","6.12.86-1","6.12.86-1~bpo12+1","6.12.88-1","6.12.88-1~bpo12+1","6.12.90-1","6.12.90-1~bpo12+1","6.12.90-2","6.12.90-2~bpo12+1","6.12.94-1","6.12.94-1~bpo12+1","6.12.95-1","6.12.95-1~bpo12+1","6.12.96-1","6.13.10-1~exp1","6.13.11-1~exp1","6.13.2-1~exp1","6.13.3-1~exp1","6.13.4-1~exp1","6.13.5-1~exp1","6.13.6-1~exp1","6.13.7-1~exp1","6.13.8-1~exp1","6.13.9-1~exp1","6.13~rc6-1~exp1","6.13~rc7-1~exp1","6.14.3-1~exp1","6.14.5-1~exp1","6.14.6-1~exp1","6.15-1~exp1","6.15.1-1~exp1","6.15.2-1~exp1","6.15.3-1~exp1","6.15.4-1~exp1","6.15.5-1~exp1","6.15.6-1~exp1","6.15~rc7-1~exp1","6.16-1~exp1","6.16.1-1~exp1","6.16.10-1","6.16.11-1","6.16.12-1","6.16.12-1~bpo13+1","6.16.12-2","6.16.3-1","6.16.3-1~bpo13+1","6.16.5-1","6.16.6-1","6.16.7-1","6.16.8-1","6.16.9-1","6.16~rc7-1~exp1","6.17.10-1","6.17.11-1","6.17.12-1","6.17.13-1","6.17.13-1~bpo13+1","6.17.2-1~exp1","6.17.5-1~exp1","6.17.6-1","6.17.7-1","6.17.7-2","6.17.8-1","6.17.8-1~bpo13+1","6.17.9-1","6.18.1-1~exp1","6.18.10-1","6.18.12-1","6.18.12-1~bpo13+1","6.18.13-1","6.18.14-1","6.18.15-1","6.18.15-1~bpo13+1","6.18.2-1~exp1","6.18.3-1","6.18.5-1","6.18.5-1~bpo13+1","6.18.8-1","6.18.9-1","6.18.9-1~bpo13+1","6.18~rc4-1~exp1","6.18~rc4-1~exp2","6.18~rc5-1~exp1","6.18~rc6-1~exp1","6.18~rc7-1~exp1","6.19-1~exp1","6.19.2-1~exp1","6.19.3-1~exp1","6.19.4-1~exp1","6.19.5-1~exp1","6.19.6-1","6.19.6-2","6.19.6-2~bpo13+1","6.19.8-1~bpo13+1","6.19~rc4-1~exp1","6.19~rc5-1~exp1","6.19~rc6-1~exp1","6.19~rc7-1~exp1","6.19~rc8-1~exp1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-23345.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"}]}