CVE-2022-50773
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 versions
Linux kernel versions
2.6.19
and later are affected. Fixed in
4.9.337,
4.14.303,
4.19.270,
5.4.229,
5.10.163,
5.15.86,
6.0.16,
6.1.2,
6.2
and their respective stable series.
References
The following references provide additional information about CVE-2022-50773 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.
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PatchKernel patch commithttps://git.kernel.org/stable/c/0649129359219ce6ff380ec401f87308485c6ae3
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PatchKernel patch commithttps://git.kernel.org/stable/c/06ec592389f2be3199779ab823c4323dcfd2121f
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PatchKernel patch commithttps://git.kernel.org/stable/c/1a763c748acd5540ccc43306c57c9c6c5fb60884
Frequently asked questions
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What is CVE-2022-50773?
CVE-2022-50773 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 2.6.19 onward and has been patched in 4.9.337, 4.14.303, 4.19.270 and others. CVE-2022-50773 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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Is there a patch available for CVE-2022-50773?
Yes — CVE-2022-50773 has been patched. Fixed versions include 4.9.337, 4.14.303, 4.19.270 and others. If you are running Linux kernel 2.6.19 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2022-50773 actively exploited?
No — CVE-2022-50773 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.