Bug 2535259 (CVE-2026-89864)

Summary: CVE-2026-89864 kernel: scsi: qla2xxx: Bound i2c->length in I2C bsg handlers
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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Fixed In Version: Doc Type: ---
Doc Text:
A flaw was found in the `qla2xxx` SCSI driver in the Linux kernel. This vulnerability allows a local attacker, with `CAP_SYS_RAWIO` capabilities, to cause heap and kernel stack corruption due to unbounded length fields in I2C bsg handlers. Successful exploitation could lead to privilege escalation or arbitrary code execution within the kernel.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-09-16 11:40:15 UTC
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.