| From e0a2c28da11e2c2b963fc01d50acbf03045ac732 Mon Sep 17 00:00:00 2001 |
| From: George Kennedy <george.kennedy@oracle.com> |
| Date: Thu, 18 Nov 2021 14:03:28 -0500 |
| Subject: scsi: scsi_debug: Sanity check block descriptor length in resp_mode_select() |
| |
| From: George Kennedy <george.kennedy@oracle.com> |
| |
| commit e0a2c28da11e2c2b963fc01d50acbf03045ac732 upstream. |
| |
| 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 |
| |
| Link: https://lore.kernel.org/r/1637262208-28850-1-git-send-email-george.kennedy@oracle.com |
| Reported-by: syzkaller <syzkaller@googlegroups.com> |
| Acked-by: Douglas Gilbert <dgilbert@interlog.com> |
| Signed-off-by: George Kennedy <george.kennedy@oracle.com> |
| Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| drivers/scsi/scsi_debug.c | 4 ++-- |
| 1 file changed, 2 insertions(+), 2 deletions(-) |
| |
| --- a/drivers/scsi/scsi_debug.c |
| +++ b/drivers/scsi/scsi_debug.c |
| @@ -2502,11 +2502,11 @@ static int resp_mode_select(struct scsi_ |
| __func__, param_len, res); |
| md_len = mselect6 ? (arr[0] + 1) : (get_unaligned_be16(arr + 0) + 2); |
| bd_len = mselect6 ? arr[3] : get_unaligned_be16(arr + 6); |
| - if (md_len > 2) { |
| + off = bd_len + (mselect6 ? 4 : 8); |
| + if (md_len > 2 || off >= res) { |
| mk_sense_invalid_fld(scp, SDEB_IN_DATA, 0, -1); |
| return check_condition_result; |
| } |
| - off = bd_len + (mselect6 ? 4 : 8); |
| mpage = arr[off] & 0x3f; |
| ps = !!(arr[off] & 0x80); |
| if (ps) { |