Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
scsi: qla2xxx: Zero SFP DMA buffer in FRU/I2C bsg handlers
The FRU and I2C bsg handlers stage their transfer in a DMA_POOL_SIZE (256-byte) bounce buffer obtained from dma_pool_alloc(), which does not zero the allocation. They initialize only a few leading bytes before handing the buffer to qla2x00_write_sfp().
qla2x00_write_sfp() can override the transfer length with a user-supplied value:
if (len == 1) opt |= BIT_0; if (opt & BIT_0) len = *sfp;
*sfp is the first byte of the (user-controlled) payload, so len can grow up to 255. The device then DMA-reads len bytes from the 256-byte pool buffer. Since only a small prefix was written (e.g. MAX_FRU_SIZE == 36 bytes for a FRU version, one byte for a FRU status register), the hardware reads past the initialized region and writes up to ~219 bytes of stale DMA-pool heap memory to the device flash.
Allocate the buffer with dma_pool_zalloc() in all five FRU/I2C handlers so any bytes beyond the initialized data are zero rather than stale heap contents.
Details
- Affected product:
- AlmaLinux 9.2 ESU , Amazon Linux 2 ELS , CentOS 7 ELS , CentOS 8.4 ELS , CentOS 8.5 ELS , CentOS Stream 8 ELS , CloudLinux 7 ELS , Debian 10 ELS , Debian 11 ELS , Oracle Linux 7 ELS , RHEL 7 ELS , TuxCare 9.6 ESU , TuxCare 9.8 ESU , Ubuntu 16.04 ELS , Ubuntu 18.04 ELS , Ubuntu 20.04 ELS
- Affected packages:
- linux @ 5.4.0 (+17 more)
Fixes
KernelCare state
Live-patch status from KernelCare for each operating system.
| Operating system | Status | Covered kernels |
|---|---|---|
| Debian 12 | Planned | — |
| Debian 13 | Released |
17 kernels
|