CVE-2023-52484

In the Linux kernel, the following vulnerability has been resolved:
iommu/arm-smmu-v3: Fix soft lockup triggered by
arm_smmu_mm_invalidate_range When running an SVA case, the following soft
lockup is triggered:

watchdog: BUG: soft lockup - CPU#244 stuck for 26s! pstate: 83400009 (Nzcv
daif +PAN -UAO +TCO +DIT -SSBS BTYPE=–) pc :
arm_smmu_cmdq_issue_cmdlist+0x178/0xa50 lr :
arm_smmu_cmdq_issue_cmdlist+0x150/0xa50 sp : ffff8000d83ef290 x29:
ffff8000d83ef290 x28: 000000003b9aca00 x27: 0000000000000000 x26:
ffff8000d83ef3c0 x25: da86c0812194a0e8 x24: 0000000000000000 x23:
0000000000000040 x22: ffff8000d83ef340 x21: ffff0000c63980c0 x20:
0000000000000001 x19: ffff0000c6398080 x18: 0000000000000000 x17:
0000000000000000 x16: 0000000000000000 x15: ffff3000b4a3bbb0 x14:
ffff3000b4a30888 x13: ffff3000b4a3cf60 x12: 0000000000000000 x11:
0000000000000000 x10: 0000000000000000 x9 : ffffc08120e4d6bc x8 :
0000000000000000 x7 : 0000000000000000 x6 : 0000000000048cfa x5 :
0000000000000000 x4 : 0000000000000001 x3 : 000000000000000a x2 :
0000000080000000 x1 : 0000000000000000 x0 : 0000000000000001 Call trace:
arm_smmu_cmdq_issue_cmdlist+0x178/0xa50
__arm_smmu_tlb_inv_range+0x118/0x254 arm_smmu_tlb_inv_range_asid+0x6c/0x130
arm_smmu_mm_invalidate_range+0xa0/0xa4
__mmu_notifier_invalidate_range_end+0x88/0x120 unmap_vmas+0x194/0x1e0
unmap_region+0xb4/0x144 do_mas_align_munmap+0x290/0x490
do_mas_munmap+0xbc/0x124 __vm_munmap+0xa8/0x19c
__arm64_sys_munmap+0x28/0x50 invoke_syscall+0x78/0x11c
el0_svc_common.constprop.0+0x58/0x1c0 do_el0_svc+0x34/0x60
el0_svc+0x2c/0xd4 el0t_64_sync_handler+0x114/0x140 el0t_64_sync+0x1a4/0x1a8
-------------------------------------------------------------------- Note
that since 6.6-rc1 the arm_smmu_mm_invalidate_range above is renamed to
“arm_smmu_mm_arch_invalidate_secondary_tlbs”, yet the problem remains. The
commit 06ff87bae8d3 (“arm64: mm: remove unused functions and variable
protoypes”) fixed a similar lockup on the CPU MMU side. Yet, it can occur
to SMMU too, since arm_smmu_mm_arch_invalidate_secondary_tlbs() is called
typically next to MMU tlb flush function, e.g. tlb_flush_mmu_tlbonly {
tlb_flush { __flush_tlb_range { // check MAX_TLBI_OPS } }
mmu_notifier_arch_invalidate_secondary_tlbs {
arm_smmu_mm_arch_invalidate_secondary_tlbs { // does not check MAX_TLBI_OPS
} } } Clone a CMDQ_MAX_TLBI_OPS from the MAX_TLBI_OPS in tlbflush.h, since
in an SVA case SMMU uses the CPU page table, so it makes sense to align
with the tlbflush code. Then, replace per-page TLBI commands with a single
per-asid TLBI command, if the request size hits this threshold.