{ "schema_version": "1.6.1", "id": "RPI-CVE-2024-50194", "modified": "2026-10-07T17:22:01Z", "upstream": [ "CVE-2024-50194" ], "published": "2024-11-08T05:54:39Z", "summary": "arm64: probes: Fix uprobes for big-endian kernels", "details": "In the Linux kernel, the following vulnerability has been resolved:\n\narm64: probes: Fix uprobes for big-endian kernels\n\nThe arm64 uprobes code is broken for big-endian kernels as it doesn't\nconvert the in-memory instruction encoding (which is always\nlittle-endian) into the kernel's native endianness before analyzing and\nsimulating instructions. This may result in a few distinct problems:\n\n* The kernel may may erroneously reject probing an instruction which can\n safely be probed.\n\n* The kernel may erroneously erroneously permit stepping an\n instruction out-of-line when that instruction cannot be stepped\n out-of-line safely.\n\n* The kernel may erroneously simulate instruction incorrectly dur to\n interpretting the byte-swapped encoding.\n\nThe endianness mismatch isn't caught by the compiler or sparse because:\n\n* The arch_uprobe::{insn,ixol} fields are encoded as arrays of u8, so\n the compiler and sparse have no idea these contain a little-endian\n 32-bit value. The core uprobes code populates these with a memcpy()\n which similarly does not handle endianness.\n\n* While the uprobe_opcode_t type is an alias for __le32, both\n arch_uprobe_analyze_insn() and arch_uprobe_skip_sstep() cast from u8[]\n to the similarly-named probe_opcode_t, which is an alias for u32.\n Hence there is no endianness conversion warning.\n\nFix this by changing the arch_uprobe::{insn,ixol} fields to __le32 and\nadding the appropriate __le32_to_cpu() conversions prior to consuming\nthe instruction encoding. The core uprobes copies these fields as opaque\nranges of bytes, and so is unaffected by this change.\n\nAt the same time, remove MAX_UINSN_BYTES and consistently use\nAARCH64_INSN_SIZE for clarity.\n\nTested with the following:\n\n| #include \n| #include \n|\n| #define noinline __attribute__((noinline))\n|\n| static noinline void *adrp_self(void)\n| {\n| void *addr;\n|\n| asm volatile(\n| \" adrp %x0, adrp_self\\n\"\n| \" add %x0, %x0, :lo12:adrp_self\\n\"\n| : \"=r\" (addr));\n| }\n|\n|\n| int main(int argc, char *argv)\n| {\n| void *ptr = adrp_self();\n| bool equal = (ptr == adrp_self);\n|\n| printf(\"adrp_self => %p\\n\"\n| \"adrp_self() => %p\\n\"\n| \"%s\\n\",\n| adrp_self, ptr, equal ? \"EQUAL\" : \"NOT EQUAL\");\n|\n| return 0;\n| }\n\n.... where the adrp_self() function was compiled to:\n\n| 00000000004007e0 :\n| 4007e0: 90000000 adrp x0, 400000 <__ehdr_start>\n| 4007e4: 911f8000 add x0, x0, #0x7e0\n| 4007e8: d65f03c0 ret\n\nBefore this patch, the ADRP is not recognized, and is assumed to be\nsteppable, resulting in corruption of the result:\n\n| # ./adrp-self\n| adrp_self => 0x4007e0\n| adrp_self() => 0x4007e0\n| EQUAL\n| # echo 'p /root/adrp-self:0x007e0' > /sys/kernel/tracing/uprobe_events\n| # echo 1 > /sys/kernel/tracing/events/uprobes/enable\n| # ./adrp-self\n| adrp_self => 0x4007e0\n| adrp_self() => 0xffffffffff7e0\n| NOT EQUAL\n\nAfter this patch, the ADRP is correctly recognized and simulated:\n\n| # ./adrp-self\n| adrp_self => 0x4007e0\n| adrp_self() => 0x4007e0\n| EQUAL\n| #\n| # echo 'p /root/adrp-self:0x007e0' > /sys/kernel/tracing/uprobe_events\n| # echo 1 > /sys/kernel/tracing/events/uprobes/enable\n| # ./adrp-self\n| adrp_self => 0x4007e0\n| adrp_self() => 0x4007e0\n| EQUAL", "affected": [ { "package": { "ecosystem": "Raspberry Pi OS:12", "name": "linux" }, "versions": [ "1:6.1.47-1+rpt4" ], "ecosystem_specific": { "binaries": [ { "binary_name": "linux-image-6.1.0-rpi3-rpi-2712", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v6", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v7", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v7l", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v8", "binary_version": "1:6.1.47-1+rpt4" } ] }, "database_specific": { "per_version": { "1:6.1.47-1+rpt4": { "linux_commit": "655fc658a15ae7a6f37103754adb39ba52a9a14e", "upstream_version": "6.1.47", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.1.115", "compiled_filter": false } } } } ], "references": [ { "type": "ADVISORY", "url": "https://www.cve.org/CVERecord?id=CVE-2024-50194" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/b6a638cb600e13f94b5464724eaa6ab7f3349ca2" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/e6ab336213918575124d6db43dc5d3554526242e" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/cf9ddf9ed94c15564a05bbf6e9f18dffa0c7df80" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/cf60d19d40184e43d9a624e55a0da73be09e938d" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/14841bb7a531b96e2dde37423a3b33e75147c60d" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/8165bf83b8a64be801d59cd2532b0d1ffed74d00" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/3d2530c65be04e93720e30f191a7cf1a3aa8b51c" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/13f8f1e05f1dc36dbba6cba0ae03354c0dafcde7" } ], "database_specific": { "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git", "upstream_modified": "2026-05-12T04:54:46Z" } }