A flaw was found in the Linux kernel's `scsi: qla2xxx` driver. A remote attacker, by sending a specially crafted Fibre Channel Protocol (FCP) response, could cause an integer underflow. This underflow leads to an out-of-bounds read when handling sense data, potentially disclosing sensitive memory information from the kernel's heap.
In the Linux kernel, the following vulnerability has been resolved:
scsi: qla2xxx: Bound rsp_info_len to avoid OOB sense-data read
In qla2x00_status_entry(), the FWI2 status path advances sense_data and
shrinks par_sense_len by rsp_info_len:
if (IS_FWI2_CAPABLE(ha)) {
sense_data += rsp_info_len;
par_sense_len -= rsp_info_len;
}
rsp_info_len is a 32-bit value taken directly from the target's FCP
response (sf.rsp_data_len), while par_sense_len is the IOCB data area
size (28 bytes for 24xx, 60 bytes for 29xx). A hostile or buggy target
reporting an rsp_info_len larger than par_sense_len makes the unsigned
subtraction underflow to a huge value and advances sense_data out of
bounds.
The underflowed par_sense_len then defeats the cap in
qla2x00_handle_sense():
if (sense_len > par_sense_len)
sense_len = par_sense_len;
memcpy(cp->sense_buffer, sense_data, sense_len);
so the memcpy reads up to SCSI_SENSE_BUFFERSIZE bytes from the
out-of-bounds sense_data pointer, leaking adjacent response-ring/heap
memory into the command's sense buffer.
Clamp rsp_info_len to par_sense_len before the subtraction so
par_sense_len can never underflow and sense_data stays within the IOCB
data area. The fix sits before the comp_status switch, covering both
qla2x00_handle_sense() call sites.
Comment 1Mauro Matteo Cascella
2026-09-17 11:47:30 UTC
In the Linux kernel, the following vulnerability has been resolved: scsi: qla2xxx: Bound rsp_info_len to avoid OOB sense-data read In qla2x00_status_entry(), the FWI2 status path advances sense_data and shrinks par_sense_len by rsp_info_len: if (IS_FWI2_CAPABLE(ha)) { sense_data += rsp_info_len; par_sense_len -= rsp_info_len; } rsp_info_len is a 32-bit value taken directly from the target's FCP response (sf.rsp_data_len), while par_sense_len is the IOCB data area size (28 bytes for 24xx, 60 bytes for 29xx). A hostile or buggy target reporting an rsp_info_len larger than par_sense_len makes the unsigned subtraction underflow to a huge value and advances sense_data out of bounds. The underflowed par_sense_len then defeats the cap in qla2x00_handle_sense(): if (sense_len > par_sense_len) sense_len = par_sense_len; memcpy(cp->sense_buffer, sense_data, sense_len); so the memcpy reads up to SCSI_SENSE_BUFFERSIZE bytes from the out-of-bounds sense_data pointer, leaking adjacent response-ring/heap memory into the command's sense buffer. Clamp rsp_info_len to par_sense_len before the subtraction so par_sense_len can never underflow and sense_data stays within the IOCB data area. The fix sits before the comp_status switch, covering both qla2x00_handle_sense() call sites.