CVE-2026-89864 scsi: qla2xxx: Bound i2c->length in I2C bsg handlers
A local attacker with CAP_SYS_RAWIO can trigger a buffer overflow in the qla2xxx SCSI driver, leading to kernel memory corruption and potential privilege escalation.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-89864?
CVE-2026-89864 is a memory corruption vulnerability in Linux, published on 16 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
scsi: qla2xxx: Bound i2c->length in I2C bsg handlers
struct qla_i2c_access carries a 16-bit length field alongside a fixed 64-byte buffer:
struct qla_i2c_access { uint16_t device, offset, option, length; uint8_t buffer[0x40]; } __packed;
qla2x00_write_i2c() and qla2x00_read_i2c() use the user-supplied i2c->length without any bounds check. i2c is overlaid on a 256-byte on-stack buffer and sfp is a 256-byte DMA-pool buffer, so a length up to 65535 overruns both:
- write: memcpy(sfp, i2c->buffer, i2c->length) over-reads the stack and over-writes the sfp heap buffer, and qla2x00_write_sfp() then DMAs i2c->length bytes out of the 256-byte buffer. - read: qla2x00_read_sfp() DMAs i2c->length bytes into the 256-byte sfp, then memcpy(i2c->buffer, sfp, i2c->length) overflows the 64-byte buffer inside the on-stack array.
A caller holding CAP_SYS_RAWIO can use this to corrupt the heap and the kernel stack. Reject requests whose length exceeds the buffer before any copy or DMA transfer in both handlers.
Which versions are affected by CVE-2026-89864?
How do I fix CVE-2026-89864?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-89864 being exploited?
There is no known exploitation of CVE-2026-89864 in the wild and no public exploit code.
Sources
Also known as AZL-101558, BELL-CVE-2026-89864, DEBIAN-CVE-2026-89864, GHSA-vhpc-fmr8-vgcc, UBUNTU-CVE-2026-89864.