From: Siddhesh Poyarekar <siddhesh@sourceware.org>
To: Andreas Schwab <schwab@linux-m68k.org>
Cc: Siddhesh Poyarekar via Libc-alpha <libc-alpha@sourceware.org>,
fweimer@redhat.com, Qualys Security Advisory <qsa@qualys.com>
Subject: Re: [PATCH 3/3] getcwd: Set errno to ERANGE for size == 1 (CVE-2021-3999)
Date: Tue, 18 Jan 2022 19:03:38 +0530 [thread overview]
Message-ID: <82d1a081-9b1f-b2ce-5907-163669feb42e@sourceware.org> (raw)
In-Reply-To: <87wnix6uja.fsf@igel.home>
On 18/01/2022 19:00, Andreas Schwab wrote:
> On Jan 18 2022, Siddhesh Poyarekar wrote:
>
>> On 18/01/2022 18:43, Andreas Schwab wrote:
>>> On Jan 18 2022, Siddhesh Poyarekar wrote:
>>>
>>>> We then process it to try and get the cwd anyway by using the posix
>>>> variant.
>>> Which returns the appropriate error.
>>>
>>
>> In the specific case of an unprivileged mount on the same directory, it
>> ends up underflowing the buffer before returning.
>
> No, it returns with ERANGE.
>
Can you tell me where the reproducer is wrong then? It clearly shows
the buffer being overwritten where it shouldn't be.
Thanks,
Siddhesh
next prev parent reply other threads:[~2022-01-18 13:33 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-18 9:07 [PATCH 0/3] Fixes for CVE-2021-3998 and CVE-2021-3999 Siddhesh Poyarekar
2022-01-18 9:07 ` [PATCH 1/3] support: Add helpers to create paths longer than PATH_MAX Siddhesh Poyarekar
2022-01-18 19:42 ` Adhemerval Zanella
2022-01-19 1:33 ` Siddhesh Poyarekar
2022-01-18 9:07 ` [PATCH 2/3] realpath: Set errno to ENAMETOOLONG for result larger than PATH_MAX [BZ #28770] Siddhesh Poyarekar
2022-01-18 19:43 ` Adhemerval Zanella
2022-01-18 9:07 ` [PATCH 3/3] getcwd: Set errno to ERANGE for size == 1 (CVE-2021-3999) Siddhesh Poyarekar
2022-01-18 11:52 ` Andreas Schwab
2022-01-18 13:10 ` Siddhesh Poyarekar
2022-01-18 13:13 ` Andreas Schwab
2022-01-18 13:16 ` Siddhesh Poyarekar
2022-01-18 13:30 ` Andreas Schwab
2022-01-18 13:33 ` Siddhesh Poyarekar [this message]
2022-01-18 13:41 ` Andreas Schwab
2022-01-18 13:45 ` Siddhesh Poyarekar
2022-01-18 13:56 ` Siddhesh Poyarekar
2022-01-18 13:57 ` Andreas Schwab
2022-01-18 14:40 ` Siddhesh Poyarekar
2022-01-18 13:59 ` Adhemerval Zanella
2022-01-18 14:44 ` Siddhesh Poyarekar
2022-01-18 16:30 ` Adhemerval Zanella
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