{"id":"CVE-2026-90212","published":"2026-09-17T17:17:16.430","lastModified":"2026-09-17T17:17:16.430","description":"In the Linux kernel, the following vulnerability has been resolved:\n\narm64/efi: Avoid voluntary preemption with efi_mm installed\n\nGus reports a bad kernel memory access when using software PAN\n(CONFIG_ARM64_SW_TTBR0_PAN=y) on a machine with support for EFI runtime\nservices:\n\n  Unable to handle kernel access to user memory outside uaccess routines\n    at virtual address 00000000f322ff30\n  Mem abort info:\n    ESR = 0x0000000096000004\n    FSC = 0x04: level 0 translation fault\n  Internal error: Oops: 0000000096000004 [#1]  SMP\n  Workqueue: efi_rts_wq efi_call_rts\n  pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)\n  pc : efi_call_rts+0xd8/0x288\n  Call trace:\n   efi_call_rts+0xd8/0x288 (P)\n   process_one_work+0x178/0x4f8\n   worker_thread+0x194/0x328\n\nThis is because the fpsimd context management code called from\n__efi_fpsimd_begin() can preempt voluntarily, returning later to the EFI\ncode with an incorrect value for TTBR0_EL1 thanks to the deferred mm\nswitching used by the software PAN implementation.\n\nSince EFI runtime services cannot preempt voluntarily and because the\nfpsimd switching code does not rely on the TTBR0_EL1 mappings, simply\nreorder the fpsimd switch so that it occurs before we change the\npage-table.","cvssScore":null,"cvssSeverity":null,"cvssVector":null,"cwes":[],"vendors":[],"products":[],"references":[{"url":"https://git.kernel.org/stable/c/829539c4a650544cb8e5e8690f2c2d0aa2c0e298","tags":[]},{"url":"https://git.kernel.org/stable/c/e98a9d0146372b046d863164025a66ab4488b972","tags":[]}],"exploitRefs":[],"hasPoc":false,"ai":null}