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[4.19,012/131] scsi: lpfc: Fix kasan slab-out-of-bounds error in lpfc_unreg_login

Message ID 20200428182226.716275284@linuxfoundation.org
State New
Headers show
Series None | expand

Commit Message

gregkh@linuxfoundation.org April 28, 2020, 6:23 p.m. UTC 
From: James Smart <jsmart2021@gmail.com>

[ Upstream commit 38503943c89f0bafd9e3742f63f872301d44cbea ]

The following kasan bug was called out:

 BUG: KASAN: slab-out-of-bounds in lpfc_unreg_login+0x7c/0xc0 [lpfc]
 Read of size 2 at addr ffff889fc7c50a22 by task lpfc_worker_3/6676
 ...
 Call Trace:
 dump_stack+0x96/0xe0
 ? lpfc_unreg_login+0x7c/0xc0 [lpfc]
 print_address_description.constprop.6+0x1b/0x220
 ? lpfc_unreg_login+0x7c/0xc0 [lpfc]
 ? lpfc_unreg_login+0x7c/0xc0 [lpfc]
 __kasan_report.cold.9+0x37/0x7c
 ? lpfc_unreg_login+0x7c/0xc0 [lpfc]
 kasan_report+0xe/0x20
 lpfc_unreg_login+0x7c/0xc0 [lpfc]
 lpfc_sli_def_mbox_cmpl+0x334/0x430 [lpfc]
 ...

When processing the completion of a "Reg Rpi" login mailbox command in
lpfc_sli_def_mbox_cmpl, a call may be made to lpfc_unreg_login. The vpi is
extracted from the completing mailbox context and passed as an input for
the next. However, the vpi stored in the mailbox command context is an
absolute vpi, which for SLI4 represents both base + offset.  When used with
a non-zero base component, (function id > 0) this results in an
out-of-range access beyond the allocated phba->vpi_ids array.

Fix by subtracting the function's base value to get an accurate vpi number.

Link: https://lore.kernel.org/r/20200322181304.37655-2-jsmart2021@gmail.com
Signed-off-by: James Smart <jsmart2021@gmail.com>
Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/scsi/lpfc/lpfc_sli.c | 2 ++
 1 file changed, 2 insertions(+)
diff mbox series

Patch

diff --git a/drivers/scsi/lpfc/lpfc_sli.c b/drivers/scsi/lpfc/lpfc_sli.c
index a801917d3c193..a56a939792ac1 100644
--- a/drivers/scsi/lpfc/lpfc_sli.c
+++ b/drivers/scsi/lpfc/lpfc_sli.c
@@ -2472,6 +2472,8 @@  lpfc_sli_def_mbox_cmpl(struct lpfc_hba *phba, LPFC_MBOXQ_t *pmb)
 	    !pmb->u.mb.mbxStatus) {
 		rpi = pmb->u.mb.un.varWords[0];
 		vpi = pmb->u.mb.un.varRegLogin.vpi;
+		if (phba->sli_rev == LPFC_SLI_REV4)
+			vpi -= phba->sli4_hba.max_cfg_param.vpi_base;
 		lpfc_unreg_login(phba, vpi, rpi, pmb);
 		pmb->vport = vport;
 		pmb->mbox_cmpl = lpfc_sli_def_mbox_cmpl;