CVE-2021-46924: NFC: st21nfca: Fix memory leak in device probe and remove

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-02-27 · updated 2026-06-17
Weakness: CWE-401

Description

In the Linux kernel, the following vulnerability has been resolved: NFC: st21nfca: Fix memory leak in device probe and remove 'phy->pending_skb' is alloced when device probe, but forgot to free in the error handling path and remove path, this cause memory leak as follows: unreferenced object 0xffff88800bc06800 (size 512): comm "8", pid 11775, jiffies 4295159829 (age 9.032s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<00000000d66c09ce>] __kmalloc_node_track_caller+0x1ed/0x450 [<00000000c93382b3>] kmalloc_reserve+0x37/0xd0 [<000000005fea522c>] __alloc_skb+0x124/0x380 [<0000000019f29f9a>] st21nfca_hci_i2c_probe+0x170/0x8f2 Fix it by freeing 'pending_skb' in error and remove.

Affected products

Linux kernel: from 3.16.0 before 4.14.261; from 4.15.0 before 4.19.224; from 4.20.0 before 5.4.170; from 5.5.0 before 5.10.90; from 5.11.0 before 5.15.13 — fixed in 4.14.261, 4.19.224, 5.10.90, 5.15.13, 5.4.170

How to fix

Upgrade to a fixed version: Linux kernel 4.14.261, 4.19.224, 5.10.90, 5.15.13. Check the vendor advisory for mitigations.

References

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