linux/drivers/base
Brian Norris f5117c4ccb firmware: actually return NULL on failed request_firmware_nowait()
commit 715780ae4b 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 471b095dfe ("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 : [<c00653a0>]    lr : [<c054c204>]    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] [<c00653a0>] (do_raw_spin_lock) from [<c054c204>] (_raw_spin_lock+0x18/0x1c)
    [10733.951743] [<c054c204>] (_raw_spin_lock) from [<c02fec60>] (fw_free_buf+0x24/0x64)
    [10733.959388] [<c02fec60>] (fw_free_buf) from [<c02fed08>] (release_firmware+0x68/0x74)
    [10733.967207] [<c02fed08>] (release_firmware) from [<c0253828>] (trigger_async_request_store+0x60/0x124)
    [10733.976501] [<c0253828>] (trigger_async_request_store) from [<c02e873c>] (dev_attr_store+0x28/0x34)
    [10733.985533] [<c02e873c>] (dev_attr_store) from [<c017bd40>] (sysfs_kf_write+0x4c/0x58)
    [10733.993437] [<c017bd40>] (sysfs_kf_write) from [<c017b250>] (kernfs_fop_write+0x144/0x1a8)
    [10734.001689] [<c017b250>] (kernfs_fop_write) from [<c011b71c>] (__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: 471b095dfe ("firmware_class: make sure fw requests contain a name")
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Acked-by: Ming Lei <ming.lei@canonical.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
History 2016-02-02 19:48:28 +00:00
..
power PM / Sleep: fix async suspend_late/freeze_late error handling 2014-11-13 11:48:48 +00:00
regmap regmap: debugfs: Don't bother actually printing when calculating max length 2015-10-30 13:59:26 +00:00
attribute_container.c drivers/base: delete non-required instances of include <linux/init.h> 2014-02-14 14:31:37 -08:00
base.h driver core: Move driver_data back to struct device 2014-05-27 12:37:18 -07:00
bus.c driver core: bus: Goto appropriate labels on failure in bus_add_device 2015-05-06 11:33:02 +01:00
class.c sysfs: make attr namespace interface less convoluted 2013-09-26 14:50:01 -07:00
component.c drivers/base: fix devres handling for master device 2014-02-07 16:45:14 -08:00
container.c ACPI / hotplug / driver core: Handle containers in a special way 2013-12-29 15:25:48 +01:00
core.c sysfs: driver core: Fix glue dir race condition by gdp_mutex 2014-11-14 15:20:01 +00:00
cpu.c x86: align x86 arch with generic CPU modalias handling 2014-02-18 12:45:38 -08:00
dd.c driver core: Inline dev_set/get_drvdata 2014-05-27 13:46:59 -07:00
devres.c devres: fix devres_get() 2015-09-28 10:21:36 +01:00
devtmpfs.c devtmpfs: Calling delete_path() only when necessary 2013-12-19 10:10:32 -08:00
dma-buf.c dma-buf: fix trivial typo error 2014-05-05 15:28:05 +02:00
dma-coherent.c DMA-API: Change dma_declare_coherent_memory() CPU address to phys_addr_t 2014-05-20 16:55:23 -06:00
dma-contiguous.c DMA, CMA: fix possible memory leak 2014-06-23 16:47:44 -07:00
dma-mapping.c DMA-API: Change dma_declare_coherent_memory() CPU address to phys_addr_t 2014-05-20 16:55:23 -06:00
driver.c driver core: add #include <linux/sysfs.h> to core files. 2013-08-27 10:24:15 -07:00
firmware.c firmware: change firmware_kset to firmware_kobj 2008-01-24 20:40:23 -08:00
firmware_class.c firmware: actually return NULL on failed request_firmware_nowait() 2016-02-02 19:48:28 +00:00
hypervisor.c drivers/base: Add export.h for EXPORT_SYMBOL/THIS_MODULE as required. 2011-10-31 19:31:38 -04:00
init.c ACPI / hotplug / driver core: Handle containers in a special way 2013-12-29 15:25:48 +01:00
isa.c dma-mapping: replace all DMA_24BIT_MASK macro with DMA_BIT_MASK(24) 2009-04-07 08:31:12 -07:00
Kconfig cma: increase CMA_ALIGNMENT upper limit to 12 2014-06-04 16:54:08 -07:00
Makefile ACPI and power management updates for 3.14-rc1 2014-01-24 15:51:02 -08:00
map.c [PATCH] kobj_map semaphore to mutex conversion 2006-03-20 13:42:58 -08:00
memory.c drivers/base/memory.c: prohibit offlining of memory blocks with missing sections 2016-01-25 10:43:28 +00:00
module.c driver core: module.c: Use kasprintf 2010-05-21 09:37:29 -07:00
node.c mm: check if section present during memory block registering 2015-09-29 16:44:47 +01:00
pinctrl.c drivers: pinctrl sleep and idle states in the core 2013-06-16 11:56:52 +02:00
platform.c drivercore: Fix unregistration path of platform devices 2015-09-28 10:21:49 +01:00
reservation.c reservation: cross-device reservation support, v4 2013-06-28 12:02:15 +10:00
soc.c mode_t whack-a-mole: ->is_visible() returns umode_t... 2012-05-29 23:28:42 -04:00
syscore.c PM / sleep: trace events for suspend/resume 2014-06-07 00:18:07 +02:00
topology.c topology: Fix compilation warning when not in SMP 2014-04-16 14:13:26 -07:00
transport_class.c drivers/base: transport_class explicitly requires EXPORT_SYMBOL 2011-10-31 19:31:15 -04:00