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The exact root cause is unclear -- it may be an unhandled NULL return from tdp_mmu_alloc_sp(), or a violated invariant elsewhere in the map path. Crash log: BUG: kernel NULL pointer dereference, address: 0000000000000024 #PF: supervisor read access in kernel mode Oops: 0000 [#1] SMP NOPTI CPU: 2 PID: 1110212 Comm: MainLoopThread Tainted: G U OE 6.19.10-arch1-1 Hardware name: Default Default/NLXB, BIOS BQ141 06/27/2024 RIP: 0010:kvm_tdp_mmu_map+0x471/0x880 [kvm] Code: 00 00 00 80 48 2b 35 76 72 5c c8 48 c7 44 24 20 00 00 00 00 48 01 f1 48 c1 e9 0c 48 c1 e1 06 48 03 0d 4b 72 5c c8 48 8b 71 28 <0f> b6 4e 24 83 e1 0f 39 ca 0f 85 a7 02 00 00 f6 c4 08 74 26 80 7b RSP: 0018:ffffce128333f790 EFLAGS: 00010286 Reproduction: The issue was observed under heavy host memory pressure while running a KVM guest (Android emulator via QEMU). The crash is not reliably reproducible and appears to be timing-dependent. Fault injection targeting tdp_mmu_alloc_sp() increases the frequency of hitting the same code path without triggering a panic, suggesting the retry path may be a viable recovery, though the exact failure condition is still unclear. Fault injection used: sp = tdp_mmu_alloc_sp(vcpu); if (!sp || (atomic_inc_return(&fail_counter) % 100 == 0)) { if (sp) tdp_mmu_free_sp(sp); goto retry; } With this injection the guest continues running normally initially, but eventually terminates after sustained injection pressure. This is expected behavior given the repeated forced failures. A speculative fix: if (!sp) goto retry; This has not been fully verified. Sending for maintainer review. Environment: Linux 6.19.10-arch1-1 x86_64 GNU C 15.2.1 Binutils 2.46 Signed-off-by: punixcorn