Commit 94ba4f2c authored by Benjamin Gray's avatar Benjamin Gray Committed by Michael Ellerman
Browse files

selftests/powerpc: Add ptrace setup_core_pattern() null-terminator 



- malloc() does not zero the buffer,
- fread() does not null-terminate it's output,
- `cat /proc/sys/kernel/core_pattern | hexdump -C` shows the file is
  not inherently null-terminated

So using string operations on the buffer is risky. Explicitly add a null
character to the end to make it safer.

Signed-off-by: default avatarBenjamin Gray <bgray@linux.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221128041948.58339-3-bgray@linux.ibm.com
parent aecfd680

tools/testing/selftests/powerpc/ptrace/core-pkey.c

+3 −1
Original line number Diff line number Diff line
@@ -383,7 +383,7 @@ static int setup_core_pattern(char **core_pattern_, bool *changed_) 
		goto out;

	}



	ret = fread(core_pattern, 1, PATH_MAX, f);

	ret = fread(core_pattern, 1, PATH_MAX - 1, f);

	fclose(f);

	if (!ret) {

		perror("Error reading core_pattern file");
@@ -391,6 +391,8 @@ static int setup_core_pattern(char **core_pattern_, bool *changed_) 
		goto out;

	}



	core_pattern[ret] = '\0';



	/* Check whether we can predict the name of the core file. */

	if (!strcmp(core_pattern, "core") || !strcmp(core_pattern, "core.%p"))

		*changed_ = false;