Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754013Ab2KDNAo (ORCPT ); Sun, 4 Nov 2012 08:00:44 -0500 Received: from mail-pa0-f46.google.com ([209.85.220.46]:42448 "EHLO mail-pa0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754132Ab2KDNAj (ORCPT ); Sun, 4 Nov 2012 08:00:39 -0500 From: Luming Yu To: arnd@arndb.de, linux-kernel@vger.kernel.org Cc: Luming Yu , Luming Yu Subject: [PATCH 09/13] HW-latency: Fix unwanted crash caused by write to dummy debugfs interface Date: Sun, 4 Nov 2012 20:59:40 -0500 Message-Id: <1352080784-30839-10-git-send-email-luming.yu@gmail.com> X-Mailer: git-send-email 1.7.12.1 In-Reply-To: <1352080784-30839-1-git-send-email-luming.yu@gmail.com> References: <1352080784-30839-1-git-send-email-luming.yu@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3674 Lines: 60 [ 141.311906] BUG: unable to handle kernel NULL pointer dereference at 0000000000000008 [ 141.314071] IP: [] simple_attr_write+0x2c/0x100 [ 141.316195] PGD c3bd7067 PUD cb41d067 PMD 0 [ 141.318287] Oops: 0000 [#1] SMP [ 141.320338] Modules linked in: hw_latency_test lockd sunrpc iptable_mangle nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack rfcomm bnep coretemp kvm arc4 iwldvm mac80211 snd_hda_codec_hdmi snd_hda_codec_realtek option usb_wwan snd_hda_intel snd_hda_codec btusb bluetooth snd_hwdep snd_seq snd_seq_device snd_pcm iwlwifi thinkpad_acpi cfg80211 snd_page_alloc snd_timer crc32c_intel snd e1000e tpm_tis ghash_clmulni_intel tpm tpm_bios soundcore iTCO_wdt rfkill joydev microcode i2c_i801 wmi iTCO_vendor_support mei lpc_ich mfd_core pcspkr uinput i915 usb_storage i2c_algo_bit uas drm_kms_helper sdhci_pci sdhci drm mmc_core i2c_core video [ 141.329446] CPU 2 [ 141.329467] Pid: 804, comm: bash Not tainted 3.7.0-rc2+ #5 LENOVO 232045C/232045C [ 141.333922] RIP: 0010:[] [] simple_attr_write+0x2c/0x100 [ 141.336173] RSP: 0018:ffff8800cb6c3eb8 EFLAGS: 00010286 [ 141.338377] RAX: ffffffff811f8f10 RBX: ffff8800c4549600 RCX: ffff8800cb6c3f50 [ 141.340573] RDX: 0000000000000002 RSI: 00007fcbf9ef0000 RDI: ffff8800c4549600 [ 141.342744] RBP: ffff8800cb6c3ef8 R08: 000000000000000a R09: 00007fcbf9edd740 [ 141.344896] R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000002 [ 141.347017] R13: 00007fcbf9ef0000 R14: ffff8800cb6c3f50 R15: 0000000000000000 [ 141.349115] FS: 00007fcbf9edd740(0000) GS:ffff880119200000(0000) knlGS:0000000000000000 [ 141.351209] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 141.353314] CR2: 0000000000000008 CR3: 00000000c696c000 CR4: 00000000001407e0 [ 141.355457] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 141.357590] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [ 141.359685] Process bash (pid: 804, threadinfo ffff8800cb6c2000, task ffff8800cb7ccd20) [ 141.361767] Stack: [ 141.363793] ffff8800c4549600 00007fcbf9ef0000 ffff8800cb6c3ef8 ffff8800c4549600 [ 141.365864] 0000000000000002 00007fcbf9ef0000 ffff8800cb6c3f50 0000000000000000 [ 141.367905] ffff8800cb6c3f28 ffffffff811cf27f ffff8800c4549600 00007fcbf9ef0000 [ 141.369924] Call Trace: [ 141.371882] [] vfs_write+0xaf/0x190 [ 141.373827] [] sys_write+0x55/0xa0 [ 141.375745] [] system_call_fastpath+0x16/0x1b [ 141.377661] Code: 1f 44 00 00 55 48 89 e5 48 83 ec 40 48 89 5d d8 4c 89 65 e0 4c 89 6d e8 4c 89 75 f0 4c 89 7d f8 4c 8b bf 28 01 00 00 48 89 75 c8 <49> 83 7f 08 00 0f 84 b1 00 00 00 4d 8d 67 50 31 f6 49 89 d5 4c [ 141.382206] RIP [] simple_attr_write+0x2c/0x100 [ 141.384326] RSP [ 141.386401] CR2: 0000000000000008 [ 141.388548] ---[ end trace 9c28eee46fcb7871 ]--- Signed-off-by: Luming Yu --- fs/libfs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/libfs.c b/fs/libfs.c index 7cc37ca..bc51574 100644 --- a/fs/libfs.c +++ b/fs/libfs.c @@ -819,7 +819,7 @@ ssize_t simple_attr_write(struct file *file, const char __user *buf, ssize_t ret; attr = file->private_data; - if (!attr->set) + if (!attr || !attr->set) return -EACCES; ret = mutex_lock_interruptible(&attr->mutex); -- 1.7.12.1 -- 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/