CVE-2021-47576

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

scsi: scsi_debug: Sanity check block descriptor length in resp_mode_select()

In resp_mode_select() sanity check the block descriptor len to avoid UAF.

BUG: KASAN: use-after-free in resp_mode_select+0xa4c/0xb40 drivers/scsi/scsi_debug.c:2509

Read of size 1 at addr ffff888026670f50 by task scsicmd/15032

CPU: 1 PID: 15032 Comm: scsicmd Not tainted 5.15.0-01d0625 #15

Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS

Call Trace:

<TASK>

dump_stack_lvl+0x89/0xb5 lib/dump_stack.c:107

print_address_description.constprop.9+0x28/0x160 mm/kasan/report.c:257

kasan_report.cold.14+0x7d/0x117 mm/kasan/report.c:443

__asan_report_load1_noabort+0x14/0x20 mm/kasan/report_generic.c:306

resp_mode_select+0xa4c/0xb40 drivers/scsi/scsi_debug.c:2509

schedule_resp+0x4af/0x1a10 drivers/scsi/scsi_debug.c:5483

scsi_debug_queuecommand+0x8c9/0x1e70 drivers/scsi/scsi_debug.c:7537

scsi_queue_rq+0x16b4/0x2d10 drivers/scsi/scsi_lib.c:1521

blk_mq_dispatch_rq_list+0xb9b/0x2700 block/blk-mq.c:1640

__blk_mq_sched_dispatch_requests+0x28f/0x590 block/blk-mq-sched.c:325

blk_mq_sched_dispatch_requests+0x105/0x190 block/blk-mq-sched.c:358

__blk_mq_run_hw_queue+0xe5/0x150 block/blk-mq.c:1762

__blk_mq_delay_run_hw_queue+0x4f8/0x5c0 block/blk-mq.c:1839

blk_mq_run_hw_queue+0x18d/0x350 block/blk-mq.c:1891

blk_mq_sched_insert_request+0x3db/0x4e0 block/blk-mq-sched.c:474

blk_execute_rq_nowait+0x16b/0x1c0 block/blk-exec.c:63

sg_common_write.isra.18+0xeb3/0x2000 drivers/scsi/sg.c:837

sg_new_write.isra.19+0x570/0x8c0 drivers/scsi/sg.c:775

sg_ioctl_common+0x14d6/0x2710 drivers/scsi/sg.c:941

sg_ioctl+0xa2/0x180 drivers/scsi/sg.c:1166

__x64_sys_ioctl+0x19d/0x220 fs/ioctl.c:52

do_syscall_64+0x3a/0x80 arch/x86/entry/common.c:50

entry_SYSCALL_64_after_hwframe+0x44/0xae arch/x86/entry/entry_64.S:113