[PATCH 5.4 138/154] ntb_hw_switchtec: Fix shift-out-of-bounds in switchtec_ntb_mw_set_trans

Greg Kroah-Hartman
2025-04-08T12:08:25Z

From: Yajun Deng <yajun.deng@linux.dev>

[ Upstream commit de203da734fae00e75be50220ba5391e7beecdf9 ]

There is a kernel API ntb_mw_clear_trans() would pass 0 to both addr and
size. This would make xlate_pos negative.

[ 23.734156] switchtec switchtec0: MW 0: part 0 addr 0x0000000000000000 size 0x0000000000000000
[ 23.734158] ================================================================================
[ 23.734172] UBSAN: shift-out-of-bounds in drivers/ntb/hw/mscc/ntb_hw_switchtec.c:293:7
[ 23.734418] shift exponent -1 is negative

Ensuring xlate_pos is a positive or zero before BIT.

Fixes: 1e2fd202f859 ("ntb_hw_switchtec: Check for alignment of the buffer in mw_set_trans()")
Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/ntb/hw/mscc/ntb_hw_switchtec.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/ntb/hw/mscc/ntb_hw_switchtec.c b/drivers/ntb/hw/mscc/ntb_hw_switchtec.c
index db9be3ce1cd0d..4dfb0dea2bda0 100644
--- a/drivers/ntb/hw/mscc/ntb_hw_switchtec.c
+++ b/drivers/ntb/hw/mscc/ntb_hw_switchtec.c
@@ -288,7 +288,7 @@ static int switchtec_ntb_mw_set_trans(struct ntb_dev *ntb, int pidx, int widx,
if (xlate_pos < 12)
return -EINVAL;

- if (!IS_ALIGNED(addr, BIT_ULL(xlate_pos))) {
+ if (xlate_pos >= 0 && !IS_ALIGNED(addr, BIT_ULL(xlate_pos))) {
/*
* In certain circumstances we can get a buffer that is
* not aligned to its size. (Most of the time
--
2.39.5