From patchwork Mon Nov 4 11:09:58 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vinay Kumar X-Patchwork-Id: 35611 Received: (qmail 13367 invoked by alias); 4 Nov 2019 11:10:13 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Delivered-To: mailing list libc-alpha@sourceware.org Received: (qmail 13348 invoked by uid 89); 4 Nov 2019 11:10:13 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-11.0 required=5.0 tests=AWL, BAYES_00, FREEMAIL_FROM, GIT_PATCH_2, GIT_PATCH_3, KAM_ASCII_DIVIDERS, KAM_NUMSUBJECT, RCVD_IN_DNSWL_NONE, SPF_PASS autolearn=ham version=3.3.1 spammy= X-HELO: mail-qk1-f195.google.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:from:date:message-id:subject:to:cc; bh=oMAz4Ch0iCViBc9kUQ9fgij2oUs0hQwjsAFyKIPhOfM=; b=DckeEj8w7MkqJDVpV7p7O0q6bHySRIYzmzEegrGh7ifF34SCb6N9bf3RmUauec/Iz8 5gPZsQn9vXEooUxjRvv+0Wj2Cukg7KctBryKXzjj02/zjsgg2hJ84D5UuGY8m/zeGnZt K5Loa1Z6GhSyDdk5HZ2oAmMVpZ/RCsCdsbmD8HwzgptsL2G5zII1324zOTIPpm/NW5Qy bmQsac7D0ZwfYoqKwBAbiyBnU3bUh0ytbh6LCNWIbfe+4VGg+OstGeAjS5s1k7/h27GE gmC1qbx+aTHWPn/cqnyp0VI4j3Wmu5wECoT/P+gWauUSTqvyRALS4zWv7c1DVgnXPCNC 4zOQ== MIME-Version: 1.0 From: Vinay Kumar Date: Mon, 4 Nov 2019 16:39:58 +0530 Message-ID: Subject: Thread stack and heap caches - CVE-2019-1010024 To: libc-alpha@sourceware.org Cc: fweimer@redhat.com, carlos@redhat.com Hi, Regarding bug related to Thread stack and heap caches (CVE-2019-1010024). https://sourceware.org/bugzilla/show_bug.cgi?id=22852 >> One way to harden is to use a tunable for a thread stack cache, and set that to zero. Below change in glibc allocatestack.c file gives the expected output with test case. Verified on x86_64 target. ======================================================= Output with above patch in glibc trunk: strace -e mmap,munmap ./thread.out mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f387b0df000 mmap(NULL, 139704, PROT_READ, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f387b0bc000 mmap(0x7f387b0c3000, 65536, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x7000) = 0x7f387b0c3000 mmap(0x7f387b0d3000, 20480, PROT_READ, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x17000) = 0x7f387b0d3000 mmap(0x7f387b0d9000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x1c000) = 0x7f387b0d9000 mmap(0x7f387b0db000, 12728, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7f387b0db000 mmap(NULL, 1774424, PROT_READ, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f387af0a000 mmap(0x7f387af2f000, 1277952, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x25000) = 0x7f387af2f000 mmap(0x7f387b067000, 303104, PROT_READ, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x15d000) = 0x7f387b067000 mmap(0x7f387b0b2000, 24576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x1a7000) = 0x7f387b0b2000 mmap(0x7f387b0b8000, 13144, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7f387b0b8000 mmap(NULL, 12288, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f387af07000 mmap(NULL, 8392704, PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_STACK, -1, 0) = 0x7f387a706000 addr: 0x7f387af03ee0 value deadbeef malloced 0x7f3874000f70 mmap(NULL, 8392704, PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_STACK, -1, 0) = 0x7f3879f05000 addr: 0x7f387a702ee0 value 0 malloced 0x7f3874000f70 +++ exited with 0 +++ Re-sending due to bounce back of previous mail. Regards, Vinay ======================================================= --- a/nptl/allocatestack.c +++ b/nptl/allocatestack.c @@ -186,6 +186,7 @@ get_cached_stack (size_t *sizep, void **memp) struct pthread *curr; curr = list_entry (entry, struct pthread, list); + curr->stackblock_size = 0; if (FREE_P (curr) && curr->stackblock_size >= size) { if (curr->stackblock_size == size)