Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > linux.kernel > #1627161
| From | "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH v3 3/7] kprobes: validate the symbol name length |
| Date | 2017-04-20 09:30 +0200 |
| Message-ID | <tyeHo-60B-3@gated-at.bofh.it> (permalink) |
| References | <txXnb-3yQ-3@gated-at.bofh.it> <txXnc-3yQ-25@gated-at.bofh.it> <tydrX-5iV-5@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
Excerpts from Michael Ellerman's message of April 20, 2017 11:38:
> "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com> writes:
>
>> diff --git a/kernel/kprobes.c b/kernel/kprobes.c
>> index 6a128f3a7ed1..bb86681c8a10 100644
>> --- a/kernel/kprobes.c
>> +++ b/kernel/kprobes.c
>> @@ -1382,6 +1382,28 @@ bool within_kprobe_blacklist(unsigned long addr)
>> return false;
>> }
>>
>> +bool is_valid_kprobe_symbol_name(const char *name)
>> +{
>> + size_t sym_len;
>> + char *s;
>> +
>> + s = strchr(name, ':');
>> + if (s) {
>> + sym_len = strnlen(s+1, KSYM_NAME_LEN);
>> + if (sym_len <= 0 || sym_len >= KSYM_NAME_LEN)
>> + return false;
>> + sym_len = (size_t)(s - name);
>> + if (sym_len <= 0 || sym_len >= MODULE_NAME_LEN)
>> + return false;
>> + } else {
>> + sym_len = strnlen(name, MODULE_NAME_LEN);
>> + if (sym_len <= 0 || sym_len >= MODULE_NAME_LEN)
>> + return false;
>> + }
>
> I think this is probably more elaborate than it needs to be.
>
> Why not just check the string is <= (MODULE_NAME_LEN + KSYM_NAME_LEN) ?
Yes, that would be sufficient for now.
It's probably just me being paranoid, but I felt it's good to have
stricter checks for user-provided strings, to guard against future
changes to how we process this.
- Naveen
Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
[PATCH v3 3/7] kprobes: validate the symbol name length "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com> - 2017-04-19 15:00 +0200
Re: [PATCH v3 3/7] kprobes: validate the symbol name length Masami Hiramatsu <mhiramat@kernel.org> - 2017-04-19 17:40 +0200
Re: [PATCH v3 3/7] kprobes: validate the symbol name length "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com> - 2017-04-19 18:40 +0200
Re: [PATCH v3 3/7] kprobes: validate the symbol name length Masami Hiramatsu <mhiramat@kernel.org> - 2017-04-21 15:50 +0200
Re: [PATCH v3 3/7] kprobes: validate the symbol name length "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com> - 2017-04-23 17:50 +0200
Re: [PATCH v3 3/7] kprobes: validate the symbol name length Michael Ellerman <mpe@ellerman.id.au> - 2017-04-20 08:10 +0200
Re: [PATCH v3 3/7] kprobes: validate the symbol name length "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com> - 2017-04-20 09:30 +0200
[PATCH v4 4/7] powerpc/kprobes: Use safer string functions in kprobe_lookup_name() "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com> - 2017-04-21 14:40 +0200
Re: [PATCH v4 4/7] powerpc/kprobes: Use safer string functions in kprobe_lookup_name() Paul Clarke <pc@us.ibm.com> - 2017-04-21 15:40 +0200
Re: [PATCH v4 4/7] powerpc/kprobes: Use safer string functions in kprobe_lookup_name() Paul Clarke <pc@us.ibm.com> - 2017-04-21 15:40 +0200
Re: [PATCH v4 4/7] powerpc/kprobes: Use safer string functions in kprobe_lookup_name() Paul Clarke <pc@us.ibm.com> - 2017-04-21 16:00 +0200
Re: [PATCH v4 4/7] powerpc/kprobes: Use safer string functions in kprobe_lookup_name() "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com> - 2017-04-23 19:20 +0200
[PATCH v4 3/7] kprobes: validate the symbol name provided during probe registration "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com> - 2017-04-21 14:40 +0200
Re: [PATCH v4 3/7] kprobes: validate the symbol name provided during probe registration Paul Clarke <pc@us.ibm.com> - 2017-04-21 15:20 +0200
Re: [PATCH v4 3/7] kprobes: validate the symbol name provided during probe registration "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com> - 2017-04-21 15:30 +0200
Re: [PATCH v4 3/7] kprobes: validate the symbol name provided during probe registration Masami Hiramatsu <mhiramat@kernel.org> - 2017-04-21 16:00 +0200
Re: [PATCH v4 3/7] kprobes: validate the symbol name provided during probe registration Michael Ellerman <mpe@ellerman.id.au> - 2017-04-22 08:00 +0200
Re: [PATCH v4 3/7] kprobes: validate the symbol name provided during probe registration "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com> - 2017-04-23 19:50 +0200
csiph-web