CVE-2022-50773

ALSA: mts64: fix possible null-ptr-defer in snd_mts64_interrupt

N/A

Published: December 24, 2025 at 01:06 PM UTC

Updated: June 17, 2026 at 05:24 AM UTC

1 product affected across 1 vendorLinux Kernel

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Severity

N/A

Exploit prediction

EPSS 0.3%

Description

In the Linux kernel, the following vulnerability has been resolved: 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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Linux Kernel · Linux

95%

2.6.19 ≤ v < 4.14.3032.6.19 ≤ v < 4.19.2702.6.19 ≤ v < 4.9.3372.6.19 ≤ v < 5.10.1632.6.19 ≤ v < 5.15.862.6.19 ≤ v < 5.4.2292.6.19 ≤ v < 6.0.162.6.19 ≤ v < 6.1.22.6.19 ≤ v < 6.22.6.1968ab801e32bbe2caac8b8c6e6e94f41fe7d687ad

Vendor states this is fixed in 0649129359219ce6ff380ec401f87308485c6ae3 (fixed)

Vendor states this is fixed in 06ec592389f2be3199779ab823c4323dcfd2121f (fixed)

Vendor states this is fixed in 1a763c748acd5540ccc43306c57c9c6c5fb60884 (fixed)

Vendor states this is fixed in 250eed7b9994d79f9c409f954dbd08e88f5afd83 (fixed)

Vendor states this is fixed in 7e91667db38abb056da5a496d40fbd044c66bed2 (fixed)

Vendor states this is fixed in b471fe61da523a15e4cb60fa81f5a2377e4bad98 (fixed)

Vendor states this is fixed in c7e9624d90bf20f1eed6b228949396d614b94020 (fixed)

Vendor states this is fixed in cba633b24a98d957e8190ef8bc4d4cdb4f6e9313 (fixed)

Vendor states this is fixed in cf2ea3c86ad90d63d1c572b43e1ca9276b0357ad (fixed)

Vendor states this is fixed in 2.6.19 (unaffected)

Vendor states this is fixed in 4.14.303 (unaffected)

Vendor states this is fixed in 4.19.270 (unaffected)