[PATCH v4 4/7] powerpc/kprobes: Use safer string functions in kprobe_lookup_name()
Naveen N. Rao
naveen.n.rao at linux.vnet.ibm.com
Mon Apr 24 03:09:34 AEST 2017
Excerpts from Paul Clarke's message of April 21, 2017 19:22:
> Sent too soon. The suggestions don't guarantee null termination. Refined, below. (Sorry for the noise.)
Yeah, the string operations here are a bit of a minefield...
>
> On 04/21/2017 08:33 AM, Paul Clarke wrote:
>> On 04/21/2017 07:33 AM, Naveen N. Rao wrote:
>>> Convert usage of strchr()/strncpy()/strncat() to
>>> strnchr()/memcpy()/strlcat() for simpler and safer string manipulation.
>
>>> diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c
>>> index 97b5eed1f76d..c73fb6e3b43f 100644
>>> --- a/arch/powerpc/kernel/kprobes.c
>>> +++ b/arch/powerpc/kernel/kprobes.c
>>> @@ -65,28 +65,27 @@ kprobe_opcode_t *kprobe_lookup_name(const char *name, unsigned int offset)
>>> char dot_name[MODULE_NAME_LEN + 1 + KSYM_NAME_LEN];
>>> const char *modsym;
>>> bool dot_appended = false;
>>> - if ((modsym = strchr(name, ':')) != NULL) {
>>> + if ((modsym = strnchr(name, ':', MODULE_NAME_LEN)) != NULL) {
... as I just realized this is an epic FAIL! ;/
I will take my time to redo this.
- Naveen
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