Mike Rapoport 3539241b59 arm[64]/memremap: don't abuse pfn_valid() to ensure presence of linear map ... commit 260364d112 upstream. The semantics of pfn_valid() is to check presence of the memory map for a PFN and not whether a PFN is covered by the linear map. The memory map may be present for NOMAP memory regions, but they won't be mapped in the linear mapping. Accessing such regions via __va() when they are memremap()'ed will cause a crash. On v5.4.y the crash happens on qemu-arm with UEFI [1]: <1>[ 0.084476] 8<--- cut here --- <1>[ 0.084595] Unable to handle kernel paging request at virtual address dfb76000 <1>[ 0.084938] pgd = (ptrval) <1>[ 0.085038] [dfb76000] *pgd=5f7fe801, *pte=00000000, *ppte=00000000 ... <4>[ 0.093923] [<c0ed6ce8>] (memcpy) from [<c16a06f8>] (dmi_setup+0x60/0x418) <4>[ 0.094204] [<c16a06f8>] (dmi_setup) from [<c16a38d4>] (arm_dmi_init+0x8/0x10) <4>[ 0.094408] [<c16a38d4>] (arm_dmi_init) from [<c0302e9c>] (do_one_initcall+0x50/0x228) <4>[ 0.094619] [<c0302e9c>] (do_one_initcall) from [<c16011e4>] (kernel_init_freeable+0x15c/0x1f8) <4>[ 0.094841] [<c16011e4>] (kernel_init_freeable) from [<c0f028cc>] (kernel_init+0x8/0x10c) <4>[ 0.095057] [<c0f028cc>] (kernel_init) from [<c03010e8>] (ret_from_fork+0x14/0x2c) On kernels v5.10.y and newer the same crash won't reproduce on ARM because commit b10d6bca87 ("arch, drivers: replace for_each_membock() with for_each_mem_range()") changed the way memory regions are registered in the resource tree, but that merely covers up the problem. On ARM64 memory resources registered in yet another way and there the issue of wrong usage of pfn_valid() to ensure availability of the linear map is also covered. Implement arch_memremap_can_ram_remap() on ARM and ARM64 to prevent access to NOMAP regions via the linear mapping in memremap(). Link: https://lore.kernel.org/all/Yl65zxGgFzF1Okac@sirena.org.uk Link: https://lkml.kernel.org/r/20220426060107.7618-1-rppt@kernel.org Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Reported-by: "kernelci.org bot" <bot@kernelci.org> Tested-by: Mark Brown <broonie@kernel.org> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Mark Brown <broonie@kernel.org> Cc: Mark-PK Tsai <mark-pk.tsai@mediatek.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Tony Lindgren <tony@atomide.com> Cc: Will Deacon <will@kernel.org> Cc: <stable@vger.kernel.org> [5.4+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2022-05-18 10:26:56 +02:00
..
boot	ARM: dts: imx8mm-venice-gw{71xx,72xx,73xx}: fix OTG controller OC mode	2022-05-09 09:14:42 +02:00
configs	arm64: defconfig: build imx-sdma as a module	2022-04-08 14:24:00 +02:00
crypto	…
hyperv	…
include	arm[64]/memremap: don't abuse pfn_valid() to ensure presence of linear map	2022-05-18 10:26:56 +02:00
kernel	arm64: vdso: fix makefile dependency on vdso.so	2022-05-18 10:26:50 +02:00
kvm	arm64: Use the clearbhb instruction in mitigations	2022-03-11 12:22:35 +01:00
lib	arm64: mte: DC {GVA,GZVA} shouldn't be used when DCZID_EL0.DZP == 1	2022-01-27 11:03:28 +01:00
mm	arm[64]/memremap: don't abuse pfn_valid() to ensure presence of linear map	2022-05-18 10:26:56 +02:00
net	bpf, arm64: Feed byte-offset into bpf line info	2022-04-08 14:23:35 +02:00
tools	arm64: Mitigate spectre style branch history side channels	2022-03-11 12:22:35 +01:00
xen	…
Kbuild	…
Kconfig	arm64/mm: drop HAVE_ARCH_PFN_VALID	2022-04-27 14:38:50 +02:00
Kconfig.debug	…
Kconfig.platforms	…
Makefile	…