CVE-2026-89865

Published Sep 16, 2026

Description

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.

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References

Frequently Asked Questions

What is CVE-2026-89865? +
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.
How do I check if I'm vulnerable to CVE-2026-89865? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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