[gcc r15-1351] riscv: Allocate enough space to strcpy() string

[Christoph Mﾃｼllner]

https://gcc.gnu.org/g:6762d5738b02d84ad3f51e89979b48acb68db65b

commit r15-1351-g6762d5738b02d84ad3f51e89979b48acb68db65b
Author: Christoph Müllner <christoph.muellner@vrull.eu>
Date:   Fri Jun 14 20:37:04 2024 +0200

    riscv: Allocate enough space to strcpy() string
    
    I triggered an ICE on Ubuntu 24.04 when compiling code that uses
    function attributes. Looking into the sources shows that we have
    a systematic issue in the attribute handling code:
    * we determine the length with strlen() (excluding the terminating null)
    * we allocate a buffer with this length
    * we copy the original string using strcpy() (incl. the terminating null)
    
    To quote the man page of strcpy():
    "The programmer is responsible for allocating a  destination  buffer
    large  enough,  that  is, strlen(src)  + 1."
    
    The ICE looks like this:
    
    *** buffer overflow detected ***: terminated
    xtheadmempair_bench.c:14:1: internal compiler error: Aborted
       14 | {
          | ^
    0xaf3b99 crash_signal
            /home/ubuntu/src/gcc/scaleff/gcc/toplev.cc:319
    0xe5b957 strcpy
            /usr/include/riscv64-linux-gnu/bits/string_fortified.h:79
    0xe5b957 riscv_process_target_attr
            /home/ubuntu/src/gcc/scaleff/gcc/config/riscv/riscv-target-attr.cc:339
    0xe5baaf riscv_process_target_attr
            /home/ubuntu/src/gcc/scaleff/gcc/config/riscv/riscv-target-attr.cc:314
    0xe5bc5f riscv_option_valid_attribute_p(tree_node*, tree_node*, tree_node*, int)
            /home/ubuntu/src/gcc/scaleff/gcc/config/riscv/riscv-target-attr.cc:389
    0x6a31e5 handle_target_attribute
            /home/ubuntu/src/gcc/scaleff/gcc/c-family/c-attribs.cc:5915
    0x5d3a07 decl_attributes(tree_node**, tree_node*, int, tree_node*)
            /home/ubuntu/src/gcc/scaleff/gcc/attribs.cc:900
    0x5db403 c_decl_attributes
            /home/ubuntu/src/gcc/scaleff/gcc/c/c-decl.cc:5501
    0x5e8965 start_function(c_declspecs*, c_declarator*, tree_node*)
            /home/ubuntu/src/gcc/scaleff/gcc/c/c-decl.cc:10562
    0x6318ed c_parser_declaration_or_fndef
            /home/ubuntu/src/gcc/scaleff/gcc/c/c-parser.cc:2914
    0x63a8ad c_parser_external_declaration
            /home/ubuntu/src/gcc/scaleff/gcc/c/c-parser.cc:2048
    0x63b219 c_parser_translation_unit
            /home/ubuntu/src/gcc/scaleff/gcc/c/c-parser.cc:1902
    0x63b219 c_parse_file()
            /home/ubuntu/src/gcc/scaleff/gcc/c/c-parser.cc:27277
    0x68fec5 c_common_parse_file()
            /home/ubuntu/src/gcc/scaleff/gcc/c-family/c-opts.cc:1311
    Please submit a full bug report, with preprocessed source (by using -freport-bug).
    Please include the complete backtrace with any bug report.
    See <https://gcc.gnu.org/bugs/> for instructions.
    
    gcc/ChangeLog:
    
            * config/riscv/riscv-target-attr.cc (riscv_target_attr_parser::parse_arch):
            Fix allocation size of buffer.
            (riscv_process_one_target_attr): Likewise.
            (riscv_process_target_attr): Likewise.
    
    Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>

Diff:
---
 gcc/config/riscv/riscv-target-attr.cc | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/gcc/config/riscv/riscv-target-attr.cc b/gcc/config/riscv/riscv-target-attr.cc
index 1a73d69bf50d..19eb7b06d548 100644
--- a/gcc/config/riscv/riscv-target-attr.cc
+++ b/gcc/config/riscv/riscv-target-attr.cc
@@ -109,7 +109,7 @@ riscv_target_attr_parser::parse_arch (const char *str)
     {
       /* Parsing the extension list like "+<ext>[,+<ext>]*".  */
       size_t len = strlen (str);
-      std::unique_ptr<char[]> buf (new char[len]);
+      std::unique_ptr<char[]> buf (new char[len+1]);
       char *str_to_check = buf.get ();
       strcpy (str_to_check, str);
       const char *token = strtok_r (str_to_check, ",", &str_to_check);
@@ -247,7 +247,7 @@ riscv_process_one_target_attr (char *arg_str,
       return false;
     }
 
-  std::unique_ptr<char[]> buf (new char[len]);
+  std::unique_ptr<char[]> buf (new char[len+1]);
   char *str_to_check = buf.get();
   strcpy (str_to_check, arg_str);
 
@@ -334,7 +334,7 @@ riscv_process_target_attr (tree fndecl, tree args, location_t loc,
       return false;
     }
 
-  std::unique_ptr<char[]> buf (new char[len]);
+  std::unique_ptr<char[]> buf (new char[len+1]);
   char *str_to_check = buf.get ();
   strcpy (str_to_check, TREE_STRING_POINTER (args));