[PATCH v3 4/7] powerpc: kprobes: use safer string functions in kprobe_lookup_name()

From: Naveen N. Rao
Date: Wed Apr 19 2017 - 08:52:06 EST


Convert usage of strncpy()/strncat() to memcpy()/strlcat() for simpler
and safer string manipulation.

Reported-by: David Laight <David.Laight@xxxxxxxxxx>
Signed-off-by: Naveen N. Rao <naveen.n.rao@xxxxxxxxxxxxxxxxxx>
---
arch/powerpc/kernel/kprobes.c | 11 +++++------
1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c
index 97b5eed1f76d..d743bacefa8c 100644
--- a/arch/powerpc/kernel/kprobes.c
+++ b/arch/powerpc/kernel/kprobes.c
@@ -69,24 +69,23 @@ kprobe_opcode_t *kprobe_lookup_name(const char *name, unsigned int offset)
modsym++;
if (*modsym != '\0' && *modsym != '.') {
/* Convert to <module:.symbol> */
- strncpy(dot_name, name, modsym - name);
+ memcpy(dot_name, name, modsym - name);
dot_name[modsym - name] = '.';
dot_name[modsym - name + 1] = '\0';
- strncat(dot_name, modsym,
- sizeof(dot_name) - (modsym - name) - 2);
+ strlcat(dot_name, modsym, sizeof(dot_name));
dot_appended = true;
} else {
dot_name[0] = '\0';
- strncat(dot_name, name, sizeof(dot_name) - 1);
+ strlcat(dot_name, name, sizeof(dot_name));
}
} else if (name[0] != '.') {
dot_name[0] = '.';
dot_name[1] = '\0';
- strncat(dot_name, name, KSYM_NAME_LEN - 2);
+ strlcat(dot_name, name, sizeof(dot_name));
dot_appended = true;
} else {
dot_name[0] = '\0';
- strncat(dot_name, name, KSYM_NAME_LEN - 1);
+ strlcat(dot_name, name, sizeof(dot_name));
}
addr = (kprobe_opcode_t *)kallsyms_lookup_name(dot_name);
if (!addr && dot_appended) {
--
2.12.1