fix filename_set_extension to always terminate the resulting string with null #192
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…ith null
Nasm produces heap buffer overflow when invoked with the following command line:
$ nasm 1.asm
-fsanitize=address prints the following call stack:
READ of size 1 at 0x5020000000b2 thread T0
#0 0x646bbff40d3d in quote_for_pmake asm/nasm.c:744
netwide-assembler#1 0x646bbff3ffa3 in main asm/nasm.c:564
netwide-assembler#2 0x76656662a1c9 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58
netwide-assembler#3 0x76656662a28a in __libc_start_main_impl ../csu/libc-start.c:360
netwide-assembler#4 0x646bbff3be84 in _start (nasm+0x34be84)
The problem is caused by the fact that:
* ofmt::extension for raw binary file is a empty string "",
* when filename_set_extension is called with empty string as extension
it produces a non-null-terminated string,
* the result of filename_set_extension is passed to quote_for_pmake,
which expects a null-terminated string.
This commit fixes the bug by changing filename_set_extension so
it always appends the null terminator to the resulting string.
Signed-off-by: Ivan Sorokin <[email protected]>
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Nasm produces heap buffer overflow when invoked with the following command line:
-fsanitize=addressprints the following call stack:The problem is caused by the fact that:
ofmt::extensionfor raw binary file is a empty string"",filename_set_extensionis called with empty string as extension it produces a non-null-terminated string,filename_set_extensionis passed toquote_for_pmake, which expects a null-terminated string.This commit fixes the bug by changing
filename_set_extensionso it always appends the null terminator to the resulting string.