linux/sound/drivers
Gaosheng Cui cf2ea3c86a ALSA: mts64: fix possible null-ptr-defer in snd_mts64_interrupt
I got a null-ptr-defer error report when I do the following tests
on the qemu platform:

make defconfig and CONFIG_PARPORT=m, CONFIG_PARPORT_PC=m,
CONFIG_SND_MTS64=m

Then making test scripts:
cat>test_mod1.sh<<EOF
modprobe snd-mts64
modprobe snd-mts64
EOF

Executing the script, perhaps several times, we will get a null-ptr-defer
report, as follow:

syzkaller:~# ./test_mod.sh
snd_mts64: probe of snd_mts64.0 failed with error -5
modprobe: ERROR: could not insert 'snd_mts64': No such device
 BUG: kernel NULL pointer dereference, address: 0000000000000000
 #PF: supervisor write access in kernel mode
 #PF: error_code(0x0002) - not-present page
 PGD 0 P4D 0
 Oops: 0002 [#1] PREEMPT SMP PTI
 CPU: 0 PID: 205 Comm: modprobe Not tainted 6.1.0-rc8-00588-g76dcd734eca2 #6
 Call Trace:
  <IRQ>
  snd_mts64_interrupt+0x24/0xa0 [snd_mts64]
  parport_irq_handler+0x37/0x50 [parport]
  __handle_irq_event_percpu+0x39/0x190
  handle_irq_event_percpu+0xa/0x30
  handle_irq_event+0x2f/0x50
  handle_edge_irq+0x99/0x1b0
  __common_interrupt+0x5d/0x100
  common_interrupt+0xa0/0xc0
  </IRQ>
  <TASK>
  asm_common_interrupt+0x22/0x40
 RIP: 0010:_raw_write_unlock_irqrestore+0x11/0x30
  parport_claim+0xbd/0x230 [parport]
  snd_mts64_probe+0x14a/0x465 [snd_mts64]
  platform_probe+0x3f/0xa0
  really_probe+0x129/0x2c0
  __driver_probe_device+0x6d/0xc0
  driver_probe_device+0x1a/0xa0
  __device_attach_driver+0x7a/0xb0
  bus_for_each_drv+0x62/0xb0
  __device_attach+0xe4/0x180
  bus_probe_device+0x82/0xa0
  device_add+0x550/0x920
  platform_device_add+0x106/0x220
  snd_mts64_attach+0x2e/0x80 [snd_mts64]
  port_check+0x14/0x20 [parport]
  bus_for_each_dev+0x6e/0xc0
  __parport_register_driver+0x7c/0xb0 [parport]
  snd_mts64_module_init+0x31/0x1000 [snd_mts64]
  do_one_initcall+0x3c/0x1f0
  do_init_module+0x46/0x1c6
  load_module+0x1d8d/0x1e10
  __do_sys_finit_module+0xa2/0xf0
  do_syscall_64+0x37/0x90
  entry_SYSCALL_64_after_hwframe+0x63/0xcd
  </TASK>
 Kernel panic - not syncing: Fatal exception in interrupt
 Rebooting in 1 seconds..

The mts wa not initialized during interrupt,  we add check for
mts to fix this bug.

Fixes: 68ab801e32 ("[ALSA] Add snd-mts64 driver for ESI Miditerminal 4140")
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Link: https://lore.kernel.org/r/20221206061004.1222966-1-cuigaosheng1@huawei.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2022-12-06 11:12:12 +01:00
..
mpu401 ALSA: mpu401: Allocate resources with device-managed APIs 2021-07-19 16:17:30 +02:00
opl3 ALSA: drivers: opl3: Fix incorrect use of vp->state 2021-12-13 10:36:17 +01:00
opl4 ALSA: opl4: More constification 2020-01-05 16:15:08 +01:00
pcsp ALSA: pcsp: Make hrtimer forwarding more robust 2021-09-28 10:58:08 +02:00
vx ALSA: vx: Drop superfluous GFP setup 2022-08-24 08:00:26 +02:00
aloop.c ALSA: aloop: Replace runtime->status->state reference to runtime->state 2022-09-27 08:47:13 +02:00
dummy.c ALSA: dummy: Add customizable volume min/max. 2022-09-12 09:52:10 +02:00
Kconfig ALSA: Add generic serial MIDI driver using serial bus API 2022-05-12 11:54:13 +02:00
Makefile ALSA: Add generic serial MIDI driver using serial bus API 2022-05-12 11:54:13 +02:00
mtpav.c ALSA: mtpav: Don't call card private_free at probe error path 2022-04-12 17:58:43 +02:00
mts64.c ALSA: mts64: fix possible null-ptr-defer in snd_mts64_interrupt 2022-12-06 11:12:12 +01:00
portman2x4.c ALSA: serial: Fix assignment in if condition 2021-06-09 17:30:34 +02:00
serial-generic.c ALSA: Add generic serial MIDI driver using serial bus API 2022-05-12 11:54:13 +02:00
serial-u16550.c ALSA: serial-u16550: Allocate resources with device-managed APIs 2021-07-19 16:17:30 +02:00
virmidi.c ALSA: virmidi: Remove duplicated code 2022-01-06 16:08:18 +01:00