Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
crypto: atmel-sha204a - fix blocking and non-blocking rng logic
The blocking and non-blocking paths were failing to provide valid entropy due to improper buffer management. Reading the buffer starting from byte 1, only fetch the 32 bytes of random data from the return message.
Tested on an Atmel SHA204A device.
Before (here for blocking), tests showed repeatedly reading reduced bytes. $ head -c 32 /dev/hwrng | hexdump -C 00000000 02 28 85 b3 47 40 f2 ee 00 00 00 00 00 00 00 00 |.(..G@……….| 00000010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |…………….| 00000020
After, the result will be similar to the following: $ head -c 32 /dev/hwrng | hexdump -C 00000000 5a fc 3f 13 14 68 fe 06 68 0a bd 04 83 6e 09 69 |Z.?..h..h….n.i| 00000010 75 ff cf 87 10 84 3b c9 c1 df ae eb 45 53 4c c3 |u…..;…..ESL.| 00000020
Details
- Affected product:
- AlmaLinux 9.2 ESU , Amazon Linux 2 ELS , Debian 10 ELS , Debian 11 ELS , Oracle Linux 7 ELS , TuxCare 9.6 ESU , TuxCare 9.8 ESU , Ubuntu 20.04 ELS
- Affected packages:
- linux @ 4.19.0 (+7 more)
Fixes
KernelCare state
Live-patch status from KernelCare for each operating system.
| Operating system | Status | Covered kernels |
|---|---|---|
| Debian 12 | Will Not Fix |
42 kernels
|
| Debian 13 | Will Not Fix |
13 kernels
|
| Ubuntu 22.04 | Planned | — |
| Ubuntu 22.04 AWS | Planned | — |
| Ubuntu 22.04 Azure | Planned | — |
| Ubuntu 24.04 | Planned | — |
| Ubuntu 24.04 AWS | Planned | — |
| Ubuntu 26.04 | Will Not Fix | — |