From patchwork Fri Jan 29 01:18:25 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kamal Mostafa X-Patchwork-Id: 575298 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) by ozlabs.org (Postfix) with ESMTP id 7E114140134; Fri, 29 Jan 2016 12:33:59 +1100 (AEDT) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1aOxwi-0004W6-0t; Fri, 29 Jan 2016 01:33:56 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.76) (envelope-from ) id 1aOxmp-00072x-3J for kernel-team@lists.ubuntu.com; Fri, 29 Jan 2016 01:23:43 +0000 Received: from 1.general.kamal.us.vpn ([10.172.68.52] helo=fourier) by youngberry.canonical.com with esmtpsa (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.76) (envelope-from ) id 1aOxmo-0005Sm-MS; Fri, 29 Jan 2016 01:23:42 +0000 Received: from kamal by fourier with local (Exim 4.82) (envelope-from ) id 1aOxml-0004vn-RP; Thu, 28 Jan 2016 17:23:39 -0800 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Subject: [PATCH 3.19.y-ckt 167/210] firmware: actually return NULL on failed request_firmware_nowait() Date: Thu, 28 Jan 2016 17:18:25 -0800 Message-Id: <1454030348-17736-168-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1454030348-17736-1-git-send-email-kamal@canonical.com> References: <1454030348-17736-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.19 Cc: Kamal Mostafa , Brian Norris , Shuah Khan X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.14 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: kernel-team-bounces@lists.ubuntu.com 3.19.8-ckt14 -stable review patch. If anyone has any objections, please let me know. ---8<------------------------------------------------------------ From: Brian Norris commit 715780ae4bb76d6fd2f20eb78e2a9ba9769a6cdc upstream. The kerneldoc for request_firmware_nowait() says that it may call the provided cont() callback with @fw == NULL, if the firmware request fails. However, this is not the case when called with an empty string (""). This case is short-circuited by the 'name[0] == '\0'' check introduced in commit 471b095dfe0d ("firmware_class: make sure fw requests contain a name"), so _request_firmware() never gets to set the fw to NULL. Noticed while using the new 'trigger_async_request' testing hook: # printf '\x00' > /sys/devices/virtual/misc/test_firmware/trigger_async_request [10553.726178] test_firmware: loading '' [10553.729859] test_firmware: loaded: 995209091 # printf '\x00' > /sys/devices/virtual/misc/test_firmware/trigger_async_request [10733.676184] test_firmware: loading '' [10733.679855] Unable to handle kernel NULL pointer dereference at virtual address 00000004 [10733.687951] pgd = ec188000 [10733.690655] [00000004] *pgd=00000000 [10733.694240] Internal error: Oops: 5 [#1] SMP ARM [10733.698847] Modules linked in: btmrvl_sdio btmrvl bluetooth sbs_battery nf_conntrack_ipv6 nf_defrag_ipv6 ip6table_filter ip6_tables asix usbnet mwifiex_sdio mwifiex cfg80211 jitterentropy_rng drbg joydev snd_seq_midi snd_seq_midi_event snd_rawmidi snd_seq snd_seq_device ppp_async ppp_generic slhc tun [10733.725670] CPU: 0 PID: 6600 Comm: bash Not tainted 4.4.0-rc4-00351-g63d0877 #178 [10733.733137] Hardware name: Rockchip (Device Tree) [10733.737831] task: ed24f6c0 ti: ee322000 task.ti: ee322000 [10733.743222] PC is at do_raw_spin_lock+0x18/0x1a0 [10733.747831] LR is at _raw_spin_lock+0x18/0x1c [10733.752180] pc : [] lr : [] psr: a00d0013 [10733.752180] sp : ee323df8 ip : ee323e20 fp : ee323e1c [10733.763634] r10: 00000051 r9 : b6f18000 r8 : ee323f80 [10733.768847] r7 : c089cebc r6 : 00000001 r5 : 00000000 r4 : ec0e6000 [10733.775360] r3 : dead4ead r2 : c06bd140 r1 : eef913b4 r0 : 00000000 [10733.781874] Flags: NzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none [10733.788995] Control: 10c5387d Table: 2c18806a DAC: 00000051 [10733.794728] Process bash (pid: 6600, stack limit = 0xee322218) [10733.800549] Stack: (0xee323df8 to 0xee324000) [10733.804896] 3de0: ec0e6000 00000000 [10733.813059] 3e00: 00000001 c089cebc ee323f80 b6f18000 ee323e2c ee323e20 c054c204 c0065394 [10733.821221] 3e20: ee323e44 ee323e30 c02fec60 c054c1f8 ec0e7ec0 ec3fcfc0 ee323e5c ee323e48 [10733.829384] 3e40: c02fed08 c02fec48 c07dbf74 eeb05a00 ee323e8c ee323e60 c0253828 c02fecac [10733.837547] 3e60: 00000001 c0116950 ee323eac ee323e78 00000001 ec3fce00 ed2d9700 ed2d970c [10733.845710] 3e80: ee323e9c ee323e90 c02e873c c02537d4 ee323eac ee323ea0 c017bd40 c02e8720 [10733.853873] 3ea0: ee323ee4 ee323eb0 c017b250 c017bd00 00000000 00000000 f3e47a54 ec128b00 [10733.862035] 3ec0: c017b10c ee323f80 00000001 c000f504 ee322000 00000000 ee323f4c ee323ee8 [10733.870197] 3ee0: c011b71c c017b118 ee323fb0 c011bc90 becfa8d9 00000001 ec128b00 00000001 [10733.878359] 3f00: b6f18000 ee323f80 ee323f4c ee323f18 c011bc90 c0063950 ee323f3c ee323f28 [10733.886522] 3f20: c0063950 c0549138 00000001 ec128b00 00000001 ec128b00 b6f18000 ee323f80 [10733.894684] 3f40: ee323f7c ee323f50 c011bed8 c011b6ec c0135fb8 c0135f24 ec128b00 ec128b00 [10733.902847] 3f60: 00000001 b6f18000 c000f504 ee322000 ee323fa4 ee323f80 c011c664 c011be24 [10733.911009] 3f80: 00000000 00000000 00000001 b6f18000 b6e79be0 00000004 00000000 ee323fa8 [10733.919172] 3fa0: c000f340 c011c618 00000001 b6f18000 00000001 b6f18000 00000001 00000000 [10733.927334] 3fc0: 00000001 b6f18000 b6e79be0 00000004 00000001 00000001 8068a3f1 b6e79c84 [10733.935496] 3fe0: 00000000 becfa7dc b6de194d b6e20246 400d0030 00000001 7a4536e8 49bda390 [10733.943664] [] (do_raw_spin_lock) from [] (_raw_spin_lock+0x18/0x1c) [10733.951743] [] (_raw_spin_lock) from [] (fw_free_buf+0x24/0x64) [10733.959388] [] (fw_free_buf) from [] (release_firmware+0x68/0x74) [10733.967207] [] (release_firmware) from [] (trigger_async_request_store+0x60/0x124) [10733.976501] [] (trigger_async_request_store) from [] (dev_attr_store+0x28/0x34) [10733.985533] [] (dev_attr_store) from [] (sysfs_kf_write+0x4c/0x58) [10733.993437] [] (sysfs_kf_write) from [] (kernfs_fop_write+0x144/0x1a8) [10734.001689] [] (kernfs_fop_write) from [] (__vfs_write+0x3c/0xe4) After this patch: # printf '\x00' > /sys/devices/virtual/misc/test_firmware/trigger_async_request [ 32.126322] test_firmware: loading '' [ 32.129995] test_firmware: failed to async load firmware -bash: printf: write error: No such device Fixes: 471b095dfe0d ("firmware_class: make sure fw requests contain a name") Signed-off-by: Brian Norris Acked-by: Ming Lei Acked-by: Kees Cook Signed-off-by: Shuah Khan Signed-off-by: Kamal Mostafa --- drivers/base/firmware_class.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c index 58470c3..eb5845b 100644 --- a/drivers/base/firmware_class.c +++ b/drivers/base/firmware_class.c @@ -1097,15 +1097,17 @@ static int _request_firmware(const struct firmware **firmware_p, const char *name, struct device *device, unsigned int opt_flags) { - struct firmware *fw; + struct firmware *fw = NULL; long timeout; int ret; if (!firmware_p) return -EINVAL; - if (!name || name[0] == '\0') - return -EINVAL; + if (!name || name[0] == '\0') { + ret = -EINVAL; + goto out; + } ret = _request_firmware_prepare(&fw, name, device); if (ret <= 0) /* error or already assigned */