Adds symbol name length limit.

src/ebpf.rs

@@ -21,8 +21,6 @@ use byteorder::{ByteOrder, LittleEndian};
 use hash32::{Hash, Hasher, Murmur3Hasher};
 use std::fmt;
 
-/// Maximum number of instructions in an eBPF program.
-pub const PROG_MAX_INSNS: usize = 65_536;
 /// Size of an eBPF instructions, in bytes.
 pub const INSN_SIZE: usize = 8;
 /// Stack register
@@ -35,6 +33,8 @@ pub const SCRATCH_REGS: usize = 4;
 /// Instruction numbers typically start at 29 in the ELF dump, use this offset
 /// when reporting so that trace aligns with the dump.
 pub const ELF_INSN_DUMP_OFFSET: usize = 29;
+/// Maximum number of characters in a symbol name.
+pub const MAX_SYMBOL_NAME_LENGTH: usize = 256;
 
 // Memory map
 // +-----------------+

src/elf.rs

@@ -86,10 +86,14 @@ pub enum ElfError {
     /// Unknown symbol
     #[error("Unknown symbol with index {0}")]
     UnknownSymbol(usize),
+    /// Symbol name too long
+    #[error("The name of a symbol is too long")]
+    SymbolNameTooLong,
     /// Offset or value is out of bounds
     #[error("Offset or value is out of bounds")]
     OutOfBounds,
 }
+
 impl From<GoblinError> for ElfError {
     fn from(error: GoblinError) -> Self {
         match error {
@@ -621,6 +625,9 @@ impl<'a, E: UserDefinedError, I: InstructionMeter> EBpfElf<E, I> {
                         .dynstrtab
                         .get_at(sym.st_name)
                         .ok_or(ElfError::UnknownSymbol(sym.st_name))?;
+                    if name.len() > ebpf::MAX_SYMBOL_NAME_LENGTH {
+                        return Err(ElfError::SymbolNameTooLong);
+                    }
                     let hash = if sym.is_function() && sym.st_value != 0 {
                         // bpf call
                         if !text_section.vm_range().contains(&(sym.st_value as usize)) {
@@ -660,6 +667,9 @@ impl<'a, E: UserDefinedError, I: InstructionMeter> EBpfElf<E, I> {
                 .strtab
                 .get_at(symbol.st_name)
                 .ok_or(ElfError::UnknownSymbol(symbol.st_name))?;
+            if name.len() > ebpf::MAX_SYMBOL_NAME_LENGTH {
+                return Err(ElfError::SymbolNameTooLong);
+            }
             register_bpf_function(bpf_functions, target_pc, &name)?;
         }