CVE-2022-50477 rtc: class: Fix potential memleak in devm_rtc_allocate_device()
A memory leak in the Linux kernel RTC driver can lead to resource exhaustion and denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2022-50477?
CVE-2022-50477 is a medium-severity memory corruption vulnerability in Linux kernel, published on 4 Oct 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
rtc: class: Fix potential memleak in devm_rtc_allocate_device()
devm_rtc_allocate_device() will alloc a rtc_device first, and then run dev_set_name(). If dev_set_name() failed, the rtc_device will memleak. Move devm_add_action_or_reset() in front of dev_set_name() to prevent memleak.
unreferenced object 0xffff888110a53000 (size 2048): comm "python3", pid 470, jiffies 4296078308 (age 58.882s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 08 30 a5 10 81 88 ff ff .........0...... 08 30 a5 10 81 88 ff ff 00 00 00 00 00 00 00 00 .0.............. backtrace: [<000000004aac0364>] kmalloc_trace+0x21/0x110 [<000000000ff02202>] devm_rtc_allocate_device+0xd4/0x400 [<000000001bdf5639>] devm_rtc_device_register+0x1a/0x80 [<00000000351bf81c>] rx4581_probe+0xdd/0x110 [rtc_rx4581] [<00000000f0eba0ae>] spi_probe+0xde/0x130 [<00000000bff89ee8>] really_probe+0x175/0x3f0 [<00000000128e8d84>] __driver_probe_device+0xe6/0x170 [<00000000ee5bf913>] device_driver_attach+0x32/0x80 [<00000000f3f28f92>] bind_store+0x10b/0x1a0 [<000000009ff812d8>] drv_attr_store+0x49/0x70 [<000000008139c323>] sysfs_kf_write+0x8d/0xb0 [<00000000b6146e01>] kernfs_fop_write_iter+0x214/0x2d0 [<00000000ecbe3895>] vfs_write+0x61a/0x7d0 [<00000000aa2196ea>] ksys_write+0xc8/0x190 [<0000000046a600f5>] do_syscall_64+0x37/0x90 [<00000000541a336f>] entry_SYSCALL_64_after_hwframe+0x63/0xcd
Weakness: CWE-401
Which versions are affected by CVE-2022-50477?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2022-50477?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2022-50477 being exploited?
There is no known exploitation of CVE-2022-50477 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2022-50477, GHSA-wq62-9p2f-cfr9, UBUNTU-CVE-2022-50477.