[PATCH 5.10 130/161] scsi: firewire: sbp-target: Fix overflow in sbp_make_tpg()

Greg Kroah-Hartman
2026-02-04T14:49:44Z

From: Kery Qi <qikeyu2017@gmail.com>

[ Upstream commit b2d6b1d443009ed4da2d69f5423ab38e5780505a ]

The code in sbp_make_tpg() limits "tpgt" to UINT_MAX but the data type of
"tpg->tport_tpgt" is u16. This causes a type truncation issue.

When a user creates a TPG via configfs mkdir, for example:

mkdir /sys/kernel/config/target/sbp/<wwn>/tpgt_70000

The value 70000 passes the "tpgt > UINT_MAX" check since 70000 is far less
than 4294967295. However, when assigned to the u16 field tpg->tport_tpgt,
the value is silently truncated to 4464 (70000 & 0xFFFF). This causes the
value the user specified to differ from what is actually stored, leading to
confusion and potential unexpected behavior.

Fix this by changing the type of "tpgt" to u16 and using kstrtou16() which
will properly reject values outside the u16 range.

Fixes: a511ce339780 ("sbp-target: Initial merge of firewire/ieee-1394 target mode support")
Signed-off-by: Kery Qi <qikeyu2017@gmail.com>
Link: https://patch.msgid.link/20260121114515.1829-2-qikeyu2017@gmail.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/target/sbp/sbp_target.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/target/sbp/sbp_target.c b/drivers/target/sbp/sbp_target.c
index e4a9b9fe3dfb0..9445bf3409fd1 100644
--- a/drivers/target/sbp/sbp_target.c
+++ b/drivers/target/sbp/sbp_target.c
@@ -1989,12 +1989,12 @@ static struct se_portal_group *sbp_make_tpg(struct se_wwn *wwn,
container_of(wwn, struct sbp_tport, tport_wwn);

struct sbp_tpg *tpg;
- unsigned long tpgt;
+ u16 tpgt;
int ret;

if (strstr(name, "tpgt_") != name)
return ERR_PTR(-EINVAL);
- if (kstrtoul(name + 5, 10, &tpgt) || tpgt > UINT_MAX)
+ if (kstrtou16(name + 5, 10, &tpgt))
return ERR_PTR(-EINVAL);

if (tport->tpg) {
--
2.51.0