Please consider mainline commit 9393c8de628c for stable

Dear stable kernel maintainers,

please consider including commit 9393c8de628c ("scsi: core: Handle drivers which set sg_tablesize to zero") for inclusion in stable.

The commit fixes a long standing bug that affects all SCSI low-level drivers setting sg_tablesize to zero, introduced in commit d285203c ("scsi: add support for a blk-mq based I/O path.") around kernel version 3.16.

Use of the option use_blk_mq=y in kernel versions prior to 5.1, and any use of such drivers in later kernels, will result in a null pointer dereference from the block layer.

I hadn't expected Martin Petersen to pick my fix over another one submitted by Finn Thain, so I never added CC: or Fixes: tags.

Cheers,

Michael