From: Greg Kroah-Hartman Date: Tue, 12 Apr 2022 04:46:36 +0000 (+0200) Subject: 5.10-stable patches X-Git-Tag: v4.9.310~6 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=318fd9fd0c0154b5d50808c3890a4cee5b65e54d;p=thirdparty%2Fkernel%2Fstable-queue.git 5.10-stable patches added patches: powerpc-fix-virt_addr_valid-for-64-bit-book3e-32-bit.patch --- diff --git a/queue-5.10/powerpc-fix-virt_addr_valid-for-64-bit-book3e-32-bit.patch b/queue-5.10/powerpc-fix-virt_addr_valid-for-64-bit-book3e-32-bit.patch new file mode 100644 index 00000000000..0a9395c5b9e --- /dev/null +++ b/queue-5.10/powerpc-fix-virt_addr_valid-for-64-bit-book3e-32-bit.patch @@ -0,0 +1,91 @@ +From ffa0b64e3be58519ae472ea29a1a1ad681e32f48 Mon Sep 17 00:00:00 2001 +From: Kefeng Wang +Date: Thu, 7 Apr 2022 00:57:57 +1000 +Subject: powerpc: Fix virt_addr_valid() for 64-bit Book3E & 32-bit + +From: Kefeng Wang + +commit ffa0b64e3be58519ae472ea29a1a1ad681e32f48 upstream. + +mpe: On 64-bit Book3E vmalloc space starts at 0x8000000000000000. + +Because of the way __pa() works we have: + __pa(0x8000000000000000) == 0, and therefore + virt_to_pfn(0x8000000000000000) == 0, and therefore + virt_addr_valid(0x8000000000000000) == true + +Which is wrong, virt_addr_valid() should be false for vmalloc space. +In fact all vmalloc addresses that alias with a valid PFN will return +true from virt_addr_valid(). That can cause bugs with hardened usercopy +as described below by Kefeng Wang: + + When running ethtool eth0 on 64-bit Book3E, a BUG occurred: + + usercopy: Kernel memory exposure attempt detected from SLUB object not in SLUB page?! (offset 0, size 1048)! + kernel BUG at mm/usercopy.c:99 + ... + usercopy_abort+0x64/0xa0 (unreliable) + __check_heap_object+0x168/0x190 + __check_object_size+0x1a0/0x200 + dev_ethtool+0x2494/0x2b20 + dev_ioctl+0x5d0/0x770 + sock_do_ioctl+0xf0/0x1d0 + sock_ioctl+0x3ec/0x5a0 + __se_sys_ioctl+0xf0/0x160 + system_call_exception+0xfc/0x1f0 + system_call_common+0xf8/0x200 + + The code shows below, + + data = vzalloc(array_size(gstrings.len, ETH_GSTRING_LEN)); + copy_to_user(useraddr, data, gstrings.len * ETH_GSTRING_LEN)) + + The data is alloced by vmalloc(), virt_addr_valid(ptr) will return true + on 64-bit Book3E, which leads to the panic. + + As commit 4dd7554a6456 ("powerpc/64: Add VIRTUAL_BUG_ON checks for __va + and __pa addresses") does, make sure the virt addr above PAGE_OFFSET in + the virt_addr_valid() for 64-bit, also add upper limit check to make + sure the virt is below high_memory. + + Meanwhile, for 32-bit PAGE_OFFSET is the virtual address of the start + of lowmem, high_memory is the upper low virtual address, the check is + suitable for 32-bit, this will fix the issue mentioned in commit + 602946ec2f90 ("powerpc: Set max_mapnr correctly") too. + +On 32-bit there is a similar problem with high memory, that was fixed in +commit 602946ec2f90 ("powerpc: Set max_mapnr correctly"), but that +commit breaks highmem and needs to be reverted. + +We can't easily fix __pa(), we have code that relies on its current +behaviour. So for now add extra checks to virt_addr_valid(). + +For 64-bit Book3S the extra checks are not necessary, the combination of +virt_to_pfn() and pfn_valid() should yield the correct result, but they +are harmless. + +Signed-off-by: Kefeng Wang +Reviewed-by: Christophe Leroy +[mpe: Add additional change log detail] +Signed-off-by: Michael Ellerman +Link: https://lore.kernel.org/r/20220406145802.538416-1-mpe@ellerman.id.au +Signed-off-by: Greg Kroah-Hartman +--- + arch/powerpc/include/asm/page.h | 6 +++++- + 1 file changed, 5 insertions(+), 1 deletion(-) + +--- a/arch/powerpc/include/asm/page.h ++++ b/arch/powerpc/include/asm/page.h +@@ -132,7 +132,11 @@ static inline bool pfn_valid(unsigned lo + #define virt_to_page(kaddr) pfn_to_page(virt_to_pfn(kaddr)) + #define pfn_to_kaddr(pfn) __va((pfn) << PAGE_SHIFT) + +-#define virt_addr_valid(kaddr) pfn_valid(virt_to_pfn(kaddr)) ++#define virt_addr_valid(vaddr) ({ \ ++ unsigned long _addr = (unsigned long)vaddr; \ ++ _addr >= PAGE_OFFSET && _addr < (unsigned long)high_memory && \ ++ pfn_valid(virt_to_pfn(_addr)); \ ++}) + + /* + * On Book-E parts we need __va to parse the device tree and we can't diff --git a/queue-5.10/series b/queue-5.10/series index 6f549e1b81b..919f05bf21a 100644 --- a/queue-5.10/series +++ b/queue-5.10/series @@ -168,3 +168,4 @@ arm64-module-remove-noload-from-linker-script.patch drivers-hv-vmbus-replace-smp_store_mb-with-virt_store_mb.patch irqchip-gic-gic-v3-prevent-gsi-to-sgi-translations.patch mm-sparsemem-fix-mem_section-will-never-be-null-gcc-12-warning.patch +powerpc-fix-virt_addr_valid-for-64-bit-book3e-32-bit.patch