CVE-2022-21546

In the Linux kernel, the following vulnerability has been resolved:

scsi: target: Fix WRITE_SAME No Data Buffer crash

In newer version of the SBC specs, we have a NDOB bit that indicates there is no data buffer that gets written out. If this bit is set using commands like sg_write_same –ndob we will crash in target_core_iblock/files execute_write_same handlers when we go to access the se_cmd->t_data_sg because its NULL.

This patch adds a check for the NDOB bit in the common WRITE SAME code because we dont support it. And, it adds a check for zero SG elements in each handler in case the initiator tries to send a normal WRITE SAME with no data buffer.

Weakness

A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit.

Affected Software

Potential Mitigations

References

• https://git.kernel.org/stable/c/4226622647e3e5ac06d3ebc1605b917446157510
• https://git.kernel.org/stable/c/ccd3f449052449a917a3e577d8ba0368f43b8f29
• https://git.kernel.org/linus/ccd3f449052449a917a3e577d8ba0368f43b8f29
• https://linux.oracle.com/cve/CVE-2022-21546.html
• https://lore.kernel.org/all/20220628022325.14627-2-michael.christie@oracle.com/