From: Benjamin Gray <bgray@linux.ibm.com>
To: linuxppc-dev@lists.ozlabs.org
Cc: Benjamin Gray <bgray@linux.ibm.com>, ajd@linux.ibm.com
Subject: [PATCH v2 2/7] selftests/powerpc: Add ptrace setup_core_pattern() null-terminator
Date: Wed, 23 Nov 2022 10:10:58 +1100 [thread overview]
Message-ID: <20221122231103.15829-3-bgray@linux.ibm.com> (raw)
In-Reply-To: <20221122231103.15829-1-bgray@linux.ibm.com>
- 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: Benjamin Gray <bgray@linux.ibm.com>
---
tools/testing/selftests/powerpc/ptrace/core-pkey.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/powerpc/ptrace/core-pkey.c b/tools/testing/selftests/powerpc/ptrace/core-pkey.c
index bbc05ffc5860..5c82ed9e7c65 100644
--- a/tools/testing/selftests/powerpc/ptrace/core-pkey.c
+++ b/tools/testing/selftests/powerpc/ptrace/core-pkey.c
@@ -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;
--
2.38.1
next prev parent reply other threads:[~2022-11-22 23:14 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-22 23:10 [PATCH v2 0/7] Expand selftest utils Benjamin Gray
2022-11-22 23:10 ` [PATCH v2 1/7] selftests/powerpc: Use mfspr/mtspr macros Benjamin Gray
2022-11-25 1:12 ` Andrew Donnellan
2022-11-22 23:10 ` Benjamin Gray [this message]
2022-11-22 23:10 ` [PATCH v2 3/7] selftests/powerpc: Add generic read/write file util Benjamin Gray
2022-11-22 23:11 ` [PATCH v2 4/7] selftests/powerpc: Add read/write debugfs file, int Benjamin Gray
2022-11-22 23:11 ` [PATCH v2 5/7] selftests/powerpc: Parse long/unsigned long value safely Benjamin Gray
2022-11-22 23:11 ` [PATCH v2 6/7] selftests/powerpc: Add {read,write}_{long,ulong} Benjamin Gray
2022-11-22 23:11 ` [PATCH v2 7/7] selftests/powerpc: Add automatically allocating read_file Benjamin Gray
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