diff options
| -rw-r--r-- | Source/cmELF.cxx | 40 | ||||
| -rw-r--r-- | Source/cmELF.h | 4 |
2 files changed, 37 insertions, 7 deletions
diff --git a/Source/cmELF.cxx b/Source/cmELF.cxx index 09a7e17..c6b078b 100644 --- a/Source/cmELF.cxx +++ b/Source/cmELF.cxx @@ -488,6 +488,7 @@ cmELFInternalImpl<Types>::GetDynamicSectionString(int tag) // Create an entry for this tag. Assume it is missing until found. StringEntry& se = this->DynamicSectionStrings[tag]; se.Position = 0; + se.Size = 0; // Try reading the dynamic section. if(!this->LoadDynamicSection()) @@ -512,14 +513,39 @@ cmELFInternalImpl<Types>::GetDynamicSectionString(int tag) ELF_Dyn& dyn = *di; if(dyn.d_tag == tag) { - // Seek to the position reported by the entry. - this->Stream.seekg(strtab.sh_offset + dyn.d_un.d_val); + // We found the tag requested. + // Make sure the position given is within the string section. + if(dyn.d_un.d_val >= strtab.sh_size) + { + this->SetErrorMessage("Section DYNAMIC references string beyond " + "the end of its string section."); + return 0; + } - // Read the string. + // Seek to the position reported by the entry. + unsigned long first = static_cast<unsigned long>(dyn.d_un.d_val); + unsigned long last = first; + unsigned long end = static_cast<unsigned long>(strtab.sh_size); + this->Stream.seekg(strtab.sh_offset + first); + + // Read the string. It may be followed by more than one NULL + // terminator. Count the total size of the region allocated to + // the string. This assumes that the next string in the table + // is non-empty, but the "chrpath" tool makes the same + // assumption. + bool terminated = false; char c; - while(this->Stream.get(c) && c != 0) + while(last != end && this->Stream.get(c) && !(terminated && c)) { - se.Value += c; + ++last; + if(c) + { + se.Value += c; + } + else + { + terminated = true; + } } // Make sure the whole value was read. @@ -531,8 +557,8 @@ cmELFInternalImpl<Types>::GetDynamicSectionString(int tag) } // The value has been read successfully. Report it. - se.Position = - static_cast<unsigned long>(strtab.sh_offset + dyn.d_un.d_val); + se.Position = static_cast<unsigned long>(strtab.sh_offset + first); + se.Size = last - first; return &se; } } diff --git a/Source/cmELF.h b/Source/cmELF.h index 716b3d2..38f1462 100644 --- a/Source/cmELF.h +++ b/Source/cmELF.h @@ -62,6 +62,10 @@ public: // The position in the file at which the string appears. unsigned long Position; + + // The size of the string table entry. This includes the space + // allocated for one or more null terminators. + unsigned long Size; }; /** Get the type of the file opened. */ |