On 2022/10/28 21:07, lijiang wrote:
> On Tue, Oct 25, 2022 at 8:00 PM <crash-utility-request@xxxxxxxxxx> wrote:
>> Date: Tue, 25 Oct 2022 05:48:25 +0000
>> From: HAGIO KAZUHITO(?????) <k-hagio-ab@xxxxxxx>
>> To: "Discussion list for crash utility usage, maintenance and
>> development" <crash-utility@xxxxxxxxxx>, Matias Ezequiel Vara Larsen
>> <matiasevara@xxxxxxxxx>
>> Subject: Re: [PATCH] Fix segmentation fault when
>> read_string() fails
>> Message-ID: <a1a0ccda-4971-e7f6-a50f-492279ff4cbd@xxxxxxx>
>> Content-Type: text/plain; charset="utf-8"
>>
>> On 2022/10/24 18:35, Matias Ezequiel Vara Larsen wrote:
>>> When read_string() fails, error() dereferences the name variable to print the
>>> nullchar that the variable points to. However, name points to a nullchar that
>>> is not in crash's memory-space thus triggering a segmentation fault. This
>>> commit replaces %s in the error message with %p so the address is printed
>>> instead.
>>
>> Thanks for the report and patch.
>>
>> I think that 'nullchar' means null-terminated string and it's a bit
>> confusing, so I will replace it with 'string'.
>>
>>>
>>> Signed-off-by: Matias Ezequiel Vara Larsen <matias.vara@xxxxxxxx>
>>> ---
>>> memory.c | 2 +-
>>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/memory.c b/memory.c
>>> index c80ef61..8a1c055 100644
>>> --- a/memory.c
>>> +++ b/memory.c
>>> @@ -6599,7 +6599,7 @@ page_flags_init_from_pageflag_names(void)
>>> }
>>>
>>> if (!read_string((ulong)name, namebuf, BUFSIZE-1)) {
>>> - error(INFO, "failed to read pageflag_names entry (i: %d name: \"%s\" mask: %ld)\n",
>>> + error(INFO, "failed to read pageflag_names entry (i: %d name: \"%p\" mask: %ld)\n",
>>
>> I will replace \"%p\" with %lx according to crash's convention.
>>
>> With the changes above,
>>
>> Acked-by: Kazuhito Hagio <k-hagio-ab@xxxxxxx>
>>
>> I can fix them when merging in this case, you don't need to resend.
>> Please wait for another ack.
>>
>
> This change looks good. So: Ack.
I changed the specifier %ld for mask to %lx too, and applied.
https://github.com/crash-utility/crash/commit/21139d9456ee41ffc8cec804dc530d6934ddac89
Thanks,
Kazu
--
Crash-utility mailing list
Crash-utility@xxxxxxxxxx
https://listman.redhat.com/mailman/listinfo/crash-utility
Contribution Guidelines: https://github.com/crash-utility/crash/wiki
