From 0e881c0a4b6146b7e856735226208f48251facd8 Mon Sep 17 00:00:00 2001
From: Tuo Li <islituo@gmail.com>
Date: Fri, 30 Jun 2023 10:47:48 +0800
Subject: [PATCH] scsi: lpfc: Fix a possible data race in
lpfc_unregister_fcf_rescan()
Git-commit: 0e881c0a4b6146b7e856735226208f48251facd8
Patch-mainline: v6.5-rc2
References: bsc#1219618 CVE-2024-24855
The variable phba->fcf.fcf_flag is often protected by the lock
phba->hbalock() when is accessed. Here is an example in
Lpfc_unregister_fcf_rescan():
spin_lock_irq(&phba->hbalock);
phba->fcf.fcf_flag |= FCF_INIT_DISC;
spin_unlock_irq(&phba->hbalock);
However, in the same function, phba->fcf.fcf_flag is assigned with 0
without holding the lock, and thus can cause a data race:
phba->fcf.fcf_flag = 0;
To fix this possible data race, a lock and unlock pair is added when
accessing the variable phba->fcf.fcf_flag.
Reported-by: BassCheck <bass@buaa.edu.cn>
Signed-off-by: Tuo Li <islituo@gmail.com>
Link: https://lore.kernel.org/r/20230630024748.1035993-1-islituo@gmail.com
Reviewed-by: Justin Tee <justin.tee@broadcom.com>
Reviewed-by: Laurence Oberman <loberman@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Vasant Karasulli <vkarasulli@suse.de>
---
drivers/scsi/lpfc/lpfc_hbadisc.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/scsi/lpfc/lpfc_hbadisc.c b/drivers/scsi/lpfc/lpfc_hbadisc.c
index 499849b58ee4..fdd7f69d87ef 100644
--- a/drivers/scsi/lpfc/lpfc_hbadisc.c
+++ b/drivers/scsi/lpfc/lpfc_hbadisc.c
@@ -6944,7 +6944,9 @@ lpfc_unregister_fcf_rescan(struct lpfc_hba *phba)
if (rc)
return;
/* Reset HBA FCF states after successful unregister FCF */
+ spin_lock_irq(&phba->hbalock);
phba->fcf.fcf_flag = 0;
+ spin_unlock_irq(&phba->hbalock);
phba->fcf.current_rec.flag = 0;
/*
--
2.34.1