/********************************************************************* * * Filename: ircomm_param.h * Version: 1.0 * Description: Parameter handling for the IrCOMM protocol * Status: Experimental. * Author: Dag Brattli * Created at: Mon Jun 7 08:47:28 1999 * Modified at: Wed Aug 25 13:46:33 1999 * Modified by: Dag Brattli * * Copyright (c) 1999 Dag Brattli, All Rights Reserved. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation; either version 2 of * the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, see . * ********************************************************************/ #ifndef IRCOMM_PARAMS_H #define IRCOMM_PARAMS_H #include /* Parameters common to all service types */ #define IRCOMM_SERVICE_TYPE 0x00 #define IRCOMM_PORT_TYPE 0x01 /* Only used in LM-IAS */ #define IRCOMM_PORT_NAME 0x02 /* Only used in LM-IAS */ /* Parameters for both 3 wire and 9 wire */ #define IRCOMM_DATA_RATE 0x10 #define IRCOMM_DATA_FORMAT 0x11 #define IRCOMM_FLOW_CONTROL 0x12 #define IRCOMM_XON_XOFF 0x13 #define IRCOMM_ENQ_ACK 0x14 #define IRCOMM_LINE_STATUS 0x15 #define IRCOMM_BREAK 0x16 /* Parameters for 9 wire */ #define IRCOMM_DTE 0x20 #define IRCOMM_DCE 0x21 #define IRCOMM_POLL 0x22 /* Service type (details) */ #define IRCOMM_3_WIRE_RAW 0x01 #define IRCOMM_3_WIRE 0x02 #define IRCOMM_9_WIRE 0x04 #define IRCOMM_CENTRONICS 0x08 /* Port type (details) */ #define IRCOMM_SERIAL 0x00 #define IRCOMM_PARALLEL 0x01 /* Data format (details) */ #define IRCOMM_WSIZE_5 0x00 #define IRCOMM_WSIZE_6 0x01 #define IRCOMM_WSIZE_7 0x02 #define IRCOMM_WSIZE_8 0x03 #define IRCOMM_1_STOP_BIT 0x00 #define IRCOMM_2_STOP_BIT 0x04 /* 1.5 if char len 5 */ #define IRCOMM_PARITY_DISABLE 0x00 #define IRCOMM_PARITY_ENABLE 0x08 #define IRCOMM_PARITY_ODD 0x00 #define IRCOMM_PARITY_EVEN 0x10 #define IRCOMM_PARITY_MARK 0x20 #define IRCOMM_PARITY_SPACE 0x30 /* Flow control */ #define IRCOMM_XON_XOFF_IN 0x01 #define IRCOMM_XON_XOFF_OUT 0x02 #define IRCOMM_RTS_CTS_IN 0x04 #define IRCOMM_RTS_CTS_OUT 0x08 #define IRCOMM_DSR_DTR_IN 0x10 #define IRCOMM_DSR_DTR_OUT 0x20 #define IRCOMM_ENQ_ACK_IN 0x40 #define IRCOMM_ENQ_ACK_OUT 0x80 /* Line status */ #define IRCOMM_OVERRUN_ERROR 0x02 #define IRCOMM_PARITY_ERROR 0x04 #define IRCOMM_FRAMING_ERROR 0x08 /* DTE (Data terminal equipment) line settings */ #define IRCOMM_DELTA_DTR 0x01 #define IRCOMM_DELTA_RTS 0x02 #define IRCOMM_DTR 0x04 #define IRCOMM_RTS 0x08 /* DCE (Data communications equipment) line settings */ #define IRCOMM_DELTA_CTS 0x01 /* Clear to send has changed */ #define IRCOMM_DELTA_DSR 0x02 /* Data set ready has changed */ #define IRCOMM_DELTA_RI 0x04 /* Ring indicator has changed */ #define IRCOMM_DELTA_CD 0x08 /* Carrier detect has changed */ #define IRCOMM_CTS 0x10 /* Clear to send is high */ #define IRCOMM_DSR 0x20 /* Data set ready is high */ #define IRCOMM_RI 0x40 /* Ring indicator is high */ #define IRCOMM_CD 0x80 /* Carrier detect is high */ #define IRCOMM_DCE_DELTA_ANY 0x0f /* * Parameter state */ struct ircomm_params { /* General control params */ __u8 service_type; __u8 port_type; char port_name[32]; /* Control params for 3- and 9-wire service type */ __u32 data_rate; /* Data rate in bps */ __u8 data_format; __u8 flow_control; char xonxoff[2]; char enqack[2]; __u8 line_status; __u8 _break; __u8 null_modem; /* Control params for 9-wire service type */ __u8 dte; __u8 dce; __u8 poll; /* Control params for Centronics service type */ }; struct ircomm_tty_cb; /* Forward decl. */ int ircomm_param_request(struct ircomm_tty_cb *self, __u8 pi, int flush); extern pi_param_info_t ircomm_param_info; #endif /* IRCOMM_PARAMS_H */ ='right'>2017-01-25 10:31:52 -0800 committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-01-27 09:19:48 +0100 commit191e885a2e130e639bb0c8ee350d7047294f2ce6 (patch) tree9bf9f9b4971df55a46e0a6750d3f6cd37bf1d9f0 /sound/soc/codecs/wm8770.c parent49def1853334396f948dcb4cedb9347abb318df5 (diff)
firmware: fix NULL pointer dereference in __fw_load_abort()
Since commit 5d47ec02c37ea6 ("firmware: Correct handling of fw_state_wait() return value") fw_load_abort() could be called twice and lead us to a kernel crash. This happens only when the firmware fallback mechanism (regular or custom) is used. The fallback mechanism exposes a sysfs interface for userspace to upload a file and notify the kernel when the file is loaded and ready, or to cancel an upload by echo'ing -1 into on the loading file: echo -n "-1" > /sys/$DEVPATH/loading This will call fw_load_abort(). Some distributions actually have a udev rule in place to *always* immediately cancel all firmware fallback mechanism requests (Debian), they have: $ cat /lib/udev/rules.d/50-firmware.rules # stub for immediately telling the kernel that userspace firmware loading # failed; necessary to avoid long timeouts with CONFIG_FW_LOADER_USER_HELPER=y SUBSYSTEM=="firmware", ACTION=="add", ATTR{loading}="-1 Distributions with this udev rule would run into this crash only if the fallback mechanism is used. Since most distributions disable by default using the fallback mechanism (CONFIG_FW_LOADER_USER_HELPER_FALLBACK), this would typicaly mean only 2 drivers which *require* the fallback mechanism could typically incur a crash: drivers/firmware/dell_rbu.c and the drivers/leds/leds-lp55xx-common.c driver. Distributions enabling CONFIG_FW_LOADER_USER_HELPER_FALLBACK by default are obviously more exposed to this crash. The crash happens because after commit 5b029624948d ("firmware: do not use fw_lock for fw_state protection") and subsequent fix commit 5d47ec02c37ea6 ("firmware: Correct handling of fw_state_wait() return value") a race can happen between this cancelation and the firmware fw_state_wait_timeout() being woken up after a state change with which fw_load_abort() as that calls swake_up(). Upon error fw_state_wait_timeout() will also again call fw_load_abort() and trigger a null reference. At first glance we could just fix this with a !buf check on fw_load_abort() before accessing buf->fw_st, however there is a logical issue in having a state machine used for the fallback mechanism and preventing access from it once we abort as its inside the buf (buf->fw_st). The firmware_class.c code is setting the buf to NULL to annotate an abort has occurred. Replace this mechanism by simply using the state check instead. All the other code in place already uses similar checks for aborting as well so no further changes are needed. An oops can be reproduced with the new fw_fallback.sh fallback mechanism cancellation test. Either cancelling the fallback mechanism or the custom fallback mechanism triggers a crash. mcgrof@piggy ~/linux-next/tools/testing/selftests/firmware (git::20170111-fw-fixes)$ sudo ./fw_fallback.sh ./fw_fallback.sh: timeout works ./fw_fallback.sh: firmware comparison works ./fw_fallback.sh: fallback mechanism works [ this then sits here when it is trying the cancellation test ] Kernel log: test_firmware: loading 'nope-test-firmware.bin' misc test_firmware: Direct firmware load for nope-test-firmware.bin failed with error -2 misc test_firmware: Falling back to user helper BUG: unable to handle kernel NULL pointer dereference at 0000000000000038 IP: _request_firmware+0xa27/0xad0 PGD 0 Oops: 0000 [#1] SMP Modules linked in: test_firmware(E) ... etc ... CPU: 1 PID: 1396 Comm: fw_fallback.sh Tainted: G W E 4.10.0-rc3-next-20170111+ #30 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.10.1-0-g8891697-prebuilt.qemu-project.org 04/01/2014 task: ffff9740b27f4340 task.stack: ffffbb15c0bc8000 RIP: 0010:_request_firmware+0xa27/0xad0 RSP: 0018:ffffbb15c0bcbd10 EFLAGS: 00010246 RAX: 00000000fffffffe RBX: ffff9740afe5aa80 RCX: 0000000000000000 RDX: ffff9740b27f4340 RSI: 0000000000000283 RDI: 0000000000000000 RBP: ffffbb15c0bcbd90 R08: ffffbb15c0bcbcd8 R09: 0000000000000000 R10: 0000000894a0d4b1 R11: 000000000000008c R12: ffffffffc0312480 R13: 0000000000000005 R14: ffff9740b1c32400 R15: 00000000000003e8 FS: 00007f8604422700(0000) GS:ffff9740bfc80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000038 CR3: 000000012164c000 CR4: 00000000000006e0 Call Trace: request_firmware+0x37/0x50 trigger_request_store+0x79/0xd0 [test_firmware] dev_attr_store+0x18/0x30 sysfs_kf_write+0x37/0x40 kernfs_fop_write+0x110/0x1a0 __vfs_write+0x37/0x160 ? _cond_resched+0x1a/0x50 vfs_write+0xb5/0x1a0 SyS_write+0x55/0xc0 ? trace_do_page_fault+0x37/0xd0 entry_SYSCALL_64_fastpath+0x1e/0xad RIP: 0033:0x7f8603f49620 RSP: 002b:00007fff6287b788 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000055c307b110a0 RCX: 00007f8603f49620 RDX: 0000000000000016 RSI: 000055c3084d8a90 RDI: 0000000000000001 RBP: 0000000000000016 R08: 000000000000c0ff R09: 000055c3084d6336 R10: 000055c307b108b0 R11: 0000000000000246 R12: 000055c307b13c80 R13: 000055c3084d6320 R14: 0000000000000000 R15: 00007fff6287b950 Code: 9f 64 84 e8 9c 61 fe ff b8 f4 ff ff ff e9 6b f9 ff ff 48 c7 c7 40 6b 8d 84 89 45 a8 e8 43 84 18 00 49 8b be 00 03 00 00 8b 45 a8 <83> 7f 38 02 74 08 e8 6e ec ff ff 8b 45 a8 49 c7 86 00 03 00 00 RIP: _request_firmware+0xa27/0xad0 RSP: ffffbb15c0bcbd10 CR2: 0000000000000038 ---[ end trace 6d94ac339c133e6f ]--- Fixes: 5d47ec02c37e ("firmware: Correct handling of fw_state_wait() return value") Reported-and-Tested-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reported-and-Tested-by: Patrick Bruenn <p.bruenn@beckhoff.com> Reported-by: Chris Wilson <chris@chris-wilson.co.uk> CC: <stable@vger.kernel.org> [3.10+] Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'sound/soc/codecs/wm8770.c')