Messages in this thread | | | Date | Fri, 21 Apr 2017 13:25:00 +0000 | From | "Naveen N. Rao" <> | Subject | Re: [PATCH v4 3/7] kprobes: validate the symbol name provided during probe registration |
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Excerpts from Paul Clarke's message of April 21, 2017 18:41: > a nit or two, below... > > On 04/21/2017 07:32 AM, Naveen N. Rao wrote: >> diff --git a/kernel/kprobes.c b/kernel/kprobes.c >> index 6a128f3a7ed1..ff9b1ac72a38 100644 >> --- a/kernel/kprobes.c >> +++ b/kernel/kprobes.c >> @@ -1383,6 +1383,34 @@ bool within_kprobe_blacklist(unsigned long addr) >> } >> >> /* >> + * We mainly want to ensure that the provided string is of a reasonable length >> + * and is of the form [<mod_name>:]<sym_name>, so that this is safe to process >> + * further. >> + * We don't worry about invalid characters as those will just prevent >> + * matching existing kallsyms. >> + */ >> +bool is_valid_kprobe_symbol_name(const char *name) >> +{ >> + size_t sym_len; >> + const char *s; >> + >> + s = strnchr(name, ':', MODULE_NAME_LEN + KSYM_NAME_LEN + 1); >> + if (s) { >> + sym_len = (size_t)(s - name); >> + if (sym_len <= 0 || sym_len >= MODULE_NAME_LEN) > > "sym_len <= 0" looks odd here, since sym_len is likely unsigned and would never be less than zero, anyway.
Ugh.. habits :/ I'll wait for Masami/Michael's feedback before re-spinning.
Thanks for the review, - Naveen
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