From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6EA18234970; Mon, 10 Mar 2025 17:26:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741627590; cv=none; b=eNBuq3qg6mXOykCyjT9wVCB0sSu4R8Fa2FqdK+dWISfozrDhSIXg8iVCKaHv6RrozCXq1kAsTJhaBO218BVBh/PwruOkl4TmBZv1SRhX0fyf7hfvvTfxbfPBPOMMgwiLGLU7hvCxAT/h1UYvdO7Ni/JF/Qo38qe5+lZ6TrqWR/8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741627590; c=relaxed/simple; bh=bCaGCj6MjvVfdxaMLs3QiqPQxl13RhRLkZURA9xyovQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=pRvHF6sPfj7THRzLQaDX5FkqnNE3FLjE+djGVN+2Pfz1t3dmTRgNscYW2OaR0gdm9FpxjPkQ1OHkXuwou5KIdZlPZYysZ6EEyzS5IZ96pi2ST49a4wOeRfV3c57TSVWQYeqxVtped+uSjXHKAFMw5mJMZZ6PK2niv3CPpIFAHUE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=L/joFH7Y; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="L/joFH7Y" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E9BE8C4CEEC; Mon, 10 Mar 2025 17:26:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1741627590; bh=bCaGCj6MjvVfdxaMLs3QiqPQxl13RhRLkZURA9xyovQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=L/joFH7Y3tWNz9mHbXchGBNZL9zM49yFDqBmuhhw07npIT3xmlCuUpnLqQ4GU0iML D7ziM+V+Ff3bjjnsv3qnz3CP4iSKqYEIDCpGsf007HcHMMRpbritkXw00UiqmVcDkR RGd8uiteFVe8p3NMoW/BiWJoqtTVV8Km1Nrq/lws= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Michael Stapelberg , Kees Cook , Sasha Levin Subject: [PATCH 6.12 149/269] coredump: Only sort VMAs when core_sort_vma sysctl is set Date: Mon, 10 Mar 2025 18:05:02 +0100 Message-ID: <20250310170503.656244583@linuxfoundation.org> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250310170457.700086763@linuxfoundation.org> References: <20250310170457.700086763@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Kees Cook [ Upstream commit 39ec9eaaa165d297d008d1fa385748430bd18e4d ] The sorting of VMAs by size in commit 7d442a33bfe8 ("binfmt_elf: Dump smaller VMAs first in ELF cores") breaks elfutils[1]. Instead, sort based on the setting of the new sysctl, core_sort_vma, which defaults to 0, no sorting. Reported-by: Michael Stapelberg Closes: https://lore.kernel.org/all/20250218085407.61126-1-michael@stapelberg.de/ [1] Fixes: 7d442a33bfe8 ("binfmt_elf: Dump smaller VMAs first in ELF cores") Signed-off-by: Kees Cook Signed-off-by: Sasha Levin --- Documentation/admin-guide/sysctl/kernel.rst | 11 +++++++++++ fs/coredump.c | 15 +++++++++++++-- 2 files changed, 24 insertions(+), 2 deletions(-) diff --git a/Documentation/admin-guide/sysctl/kernel.rst b/Documentation/admin-guide/sysctl/kernel.rst index f8bc1630eba05..fa21cdd610b21 100644 --- a/Documentation/admin-guide/sysctl/kernel.rst +++ b/Documentation/admin-guide/sysctl/kernel.rst @@ -212,6 +212,17 @@ pid>/``). This value defaults to 0. +core_sort_vma +============= + +The default coredump writes VMAs in address order. By setting +``core_sort_vma`` to 1, VMAs will be written from smallest size +to largest size. This is known to break at least elfutils, but +can be handy when dealing with very large (and truncated) +coredumps where the more useful debugging details are included +in the smaller VMAs. + + core_uses_pid ============= diff --git a/fs/coredump.c b/fs/coredump.c index 45737b43dda5c..2b8c36c9660c5 100644 --- a/fs/coredump.c +++ b/fs/coredump.c @@ -63,6 +63,7 @@ static void free_vma_snapshot(struct coredump_params *cprm); static int core_uses_pid; static unsigned int core_pipe_limit; +static unsigned int core_sort_vma; static char core_pattern[CORENAME_MAX_SIZE] = "core"; static int core_name_size = CORENAME_MAX_SIZE; unsigned int core_file_note_size_limit = CORE_FILE_NOTE_SIZE_DEFAULT; @@ -1025,6 +1026,15 @@ static struct ctl_table coredump_sysctls[] = { .extra1 = (unsigned int *)&core_file_note_size_min, .extra2 = (unsigned int *)&core_file_note_size_max, }, + { + .procname = "core_sort_vma", + .data = &core_sort_vma, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_douintvec_minmax, + .extra1 = SYSCTL_ZERO, + .extra2 = SYSCTL_ONE, + }, }; static int __init init_fs_coredump_sysctls(void) @@ -1255,8 +1265,9 @@ static bool dump_vma_snapshot(struct coredump_params *cprm) cprm->vma_data_size += m->dump_size; } - sort(cprm->vma_meta, cprm->vma_count, sizeof(*cprm->vma_meta), - cmp_vma_size, NULL); + if (core_sort_vma) + sort(cprm->vma_meta, cprm->vma_count, sizeof(*cprm->vma_meta), + cmp_vma_size, NULL); return true; } -- 2.39.5