{
   "containers": {
      "cna": {
         "providerMetadata": {
            "orgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038"
         },
         "descriptions": [
            {
               "lang": "en",
               "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nparisc: Fix random data corruption from exception handler\n\nThe current exception handler implementation, which assists when accessing\nuser space memory, may exhibit random data corruption if the compiler decides\nto use a different register than the specified register %r29 (defined in\nASM_EXCEPTIONTABLE_REG) for the error code. If the compiler choose another\nregister, the fault handler will nevertheless store -EFAULT into %r29 and thus\ntrash whatever this register is used for.\nLooking at the assembly I found that this happens sometimes in emulate_ldd().\n\nTo solve the issue, the easiest solution would be if it somehow is\npossible to tell the fault handler which register is used to hold the error\ncode. Using %0 or %1 in the inline assembly is not posssible as it will show\nup as e.g. %r29 (with the \"%r\" prefix), which the GNU assembler can not\nconvert to an integer.\n\nThis patch takes another, better and more flexible approach:\nWe extend the __ex_table (which is out of the execution path) by one 32-word.\nIn this word we tell the compiler to insert the assembler instruction\n\"or %r0,%r0,%reg\", where %reg references the register which the compiler\nchoosed for the error return code.\nIn case of an access failure, the fault handler finds the __ex_table entry and\ncan examine the opcode. The used register is encoded in the lowest 5 bits, and\nthe fault handler can then store -EFAULT into this register.\n\nSince we extend the __ex_table to 3 words we can't use the BUILDTIME_TABLE_SORT\nconfig option any longer."
            }
         ],
         "affected": [
            {
               "product": "Linux",
               "vendor": "Linux",
               "defaultStatus": "unaffected",
               "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
               "programFiles": [
                  "arch/parisc/Kconfig",
                  "arch/parisc/include/asm/assembly.h",
                  "arch/parisc/include/asm/extable.h",
                  "arch/parisc/include/asm/special_insns.h",
                  "arch/parisc/include/asm/uaccess.h",
                  "arch/parisc/kernel/cache.c",
                  "arch/parisc/kernel/unaligned.c",
                  "arch/parisc/mm/fault.c"
               ],
               "versions": [
                  {
                     "version": "1da177e4c3f4",
                     "lessThan": "23027309b099",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "1da177e4c3f4",
                     "lessThan": "fa69a8063f8b",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "1da177e4c3f4",
                     "lessThan": "ce31d79aa1f1",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "1da177e4c3f4",
                     "lessThan": "8b1d72395635",
                     "status": "affected",
                     "versionType": "git"
                  }
               ]
            },
            {
               "product": "Linux",
               "vendor": "Linux",
               "defaultStatus": "affected",
               "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
               "programFiles": [
                  "arch/parisc/Kconfig",
                  "arch/parisc/include/asm/assembly.h",
                  "arch/parisc/include/asm/extable.h",
                  "arch/parisc/include/asm/special_insns.h",
                  "arch/parisc/include/asm/uaccess.h",
                  "arch/parisc/kernel/cache.c",
                  "arch/parisc/kernel/unaligned.c",
                  "arch/parisc/mm/fault.c"
               ],
               "versions": [
                  {
                     "version": "6.1.79",
                     "lessThanOrEqual": "6.1.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "6.6.18",
                     "lessThanOrEqual": "6.6.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "6.7.6",
                     "lessThanOrEqual": "6.7.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "6.8",
                     "lessThanOrEqual": "*",
                     "status": "unaffected",
                     "versionType": "original_commit_for_fix"
                  }
               ]
            }
         ],
         "references": [
            {
               "url": "https://git.kernel.org/stable/c/23027309b099ffc4efca5477009a11dccbdae592"
            },
            {
               "url": "https://git.kernel.org/stable/c/fa69a8063f8b27f3c7434a0d4f464a76a62f24d2"
            },
            {
               "url": "https://git.kernel.org/stable/c/ce31d79aa1f13a2345791f84935281a2c194e003"
            },
            {
               "url": "https://git.kernel.org/stable/c/8b1d72395635af45410b66cc4c4ab37a12c4a831"
            }
         ],
         "title": "parisc: Fix random data corruption from exception handler",
         "x_generator": {
            "engine": "bippy-a5840b7849dd"
         }
      }
   },
   "cveMetadata": {
      "assignerOrgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038",
      "cveID": "CVE-2024-26706",
      "requesterUserId": "gregkh@kernel.org",
      "serial": "1",
      "state": "PUBLISHED"
   },
   "dataType": "CVE_RECORD",
   "dataVersion": "5.0"
}