Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754979AbaKROJ6 (ORCPT ); Tue, 18 Nov 2014 09:09:58 -0500 Received: from cantor2.suse.de ([195.135.220.15]:56994 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932107AbaKROJo (ORCPT ); Tue, 18 Nov 2014 09:09:44 -0500 From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Rabin Vincent , Steven Rostedt , Jiri Slaby Subject: [PATCH 3.12 052/206] tracing/syscalls: Ignore numbers outside NR_syscalls' range Date: Tue, 18 Nov 2014 15:06:47 +0100 Message-Id: X-Mailer: git-send-email 2.1.3 In-Reply-To: <28f04bcc068a44c5641c727883947960fb8dcbd5.1416319692.git.jslaby@suse.cz> References: <28f04bcc068a44c5641c727883947960fb8dcbd5.1416319692.git.jslaby@suse.cz> In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Rabin Vincent 3.12-stable review patch. If anyone has any objections, please let me know. =============== commit 086ba77a6db00ed858ff07451bedee197df868c9 upstream. ARM has some private syscalls (for example, set_tls(2)) which lie outside the range of NR_syscalls. If any of these are called while syscall tracing is being performed, out-of-bounds array access will occur in the ftrace and perf sys_{enter,exit} handlers. # trace-cmd record -e raw_syscalls:* true && trace-cmd report ... true-653 [000] 384.675777: sys_enter: NR 192 (0, 1000, 3, 4000022, ffffffff, 0) true-653 [000] 384.675812: sys_exit: NR 192 = 1995915264 true-653 [000] 384.675971: sys_enter: NR 983045 (76f74480, 76f74000, 76f74b28, 76f74480, 76f76f74, 1) true-653 [000] 384.675988: sys_exit: NR 983045 = 0 ... # trace-cmd record -e syscalls:* true [ 17.289329] Unable to handle kernel paging request at virtual address aaaaaace [ 17.289590] pgd = 9e71c000 [ 17.289696] [aaaaaace] *pgd=00000000 [ 17.289985] Internal error: Oops: 5 [#1] PREEMPT SMP ARM [ 17.290169] Modules linked in: [ 17.290391] CPU: 0 PID: 704 Comm: true Not tainted 3.18.0-rc2+ #21 [ 17.290585] task: 9f4dab00 ti: 9e710000 task.ti: 9e710000 [ 17.290747] PC is at ftrace_syscall_enter+0x48/0x1f8 [ 17.290866] LR is at syscall_trace_enter+0x124/0x184 Fix this by ignoring out-of-NR_syscalls-bounds syscall numbers. Commit cd0980fc8add "tracing: Check invalid syscall nr while tracing syscalls" added the check for less than zero, but it should have also checked for greater than NR_syscalls. Link: http://lkml.kernel.org/p/1414620418-29472-1-git-send-email-rabin@rab.in Fixes: cd0980fc8add "tracing: Check invalid syscall nr while tracing syscalls" Signed-off-by: Rabin Vincent Signed-off-by: Steven Rostedt Signed-off-by: Jiri Slaby --- kernel/trace/trace_syscalls.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c index 559329d9bd2f..d8ce71bbb5bf 100644 --- a/kernel/trace/trace_syscalls.c +++ b/kernel/trace/trace_syscalls.c @@ -312,7 +312,7 @@ static void ftrace_syscall_enter(void *data, struct pt_regs *regs, long id) int size; syscall_nr = trace_get_syscall_nr(current, regs); - if (syscall_nr < 0) + if (syscall_nr < 0 || syscall_nr >= NR_syscalls) return; if (!test_bit(syscall_nr, tr->enabled_enter_syscalls)) return; @@ -354,7 +354,7 @@ static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret) int syscall_nr; syscall_nr = trace_get_syscall_nr(current, regs); - if (syscall_nr < 0) + if (syscall_nr < 0 || syscall_nr >= NR_syscalls) return; if (!test_bit(syscall_nr, tr->enabled_exit_syscalls)) return; @@ -557,7 +557,7 @@ static void perf_syscall_enter(void *ignore, struct pt_regs *regs, long id) int size; syscall_nr = trace_get_syscall_nr(current, regs); - if (syscall_nr < 0) + if (syscall_nr < 0 || syscall_nr >= NR_syscalls) return; if (!test_bit(syscall_nr, enabled_perf_enter_syscalls)) return; @@ -631,7 +631,7 @@ static void perf_syscall_exit(void *ignore, struct pt_regs *regs, long ret) int size; syscall_nr = trace_get_syscall_nr(current, regs); - if (syscall_nr < 0) + if (syscall_nr < 0 || syscall_nr >= NR_syscalls) return; if (!test_bit(syscall_nr, enabled_perf_exit_syscalls)) return; -- 2.1.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/