Executive brief
A vulnerability exists in the Linux kernel's hardware monitoring driver for Delta Q54SJ108A2 power supplies. This flaw occurs when the system reads diagnostic information through the debugfs interface, potentially allowing a local user to crash the system or gain unauthorized elevated privileges. The issue affects systems using this specific hardware driver and could impact operational stability or data security.
Technical details
A stack-based buffer overflow exists in the q54sj108a2_debugfs_read function within the Linux kernel's hwmon subsystem. The vulnerability is caused by incorrect usage of the bin2hex() function, where the destination buffer ('data') was smaller than the required size for a 32-byte block read (which produces 64 hex characters). Additionally, the source and destination arguments were swapped in the original code. A local attacker with access to the debugfs interface can trigger this overflow by reading from the affected debugfs entries, leading to memory corruption. The fix involves expanding the output buffer to 66 bytes, correcting the argument order, and ensuring the correct read count is used.
Affected products
- Linux Linux Kernel Fixed in 24a7b9d, 25dd70a, 52db5ef, 73a7a34, a0fc1b9, b48a0f8, c59090c
Timeline
- 2026-03-04: patched: Initial fix committed to kernel source
- 2026-05-08: disclosed: CVE-2026-43380 published
References
- https://git.kernel.org/stable/c/24a7b9daa103fa963b3fd37d8805b23e01621976
- https://git.kernel.org/stable/c/25dd70a03b1f5f3aa71e1a5091ecd9cd2a13ee43
- https://git.kernel.org/stable/c/52db5ef163c96f916d424e472fb17aadc35a9f7a
- https://git.kernel.org/stable/c/73a7a345816946d276ad2c46c8bb771de67cfc46
- https://git.kernel.org/stable/c/a0fc1b9c738fba231f190ab960c83202722efee5
- https://git.kernel.org/stable/c/b48a0f8d4541a4f6651dc9a64430ce9fdf5c120b
- https://git.kernel.org/stable/c/c59090c50f62a17129fc4c5407bc4071305a9e82