[PATCH AUTOSEL 5.10 19/62] Revert "isdn: mISDNinfineon: fix potential NULL pointer dereference"

From: Sasha Levin
Date: Mon May 24 2021 - 10:55:59 EST


From: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

[ Upstream commit abd7bca23bd4247124265152d00ffd4b2b0d6877 ]

This reverts commit d721fe99f6ada070ae8fc0ec3e01ce5a42def0d9.

Because of recent interactions with developers from @umn.edu, all
commits from them have been recently re-reviewed to ensure if they were
correct or not.

Upon review, this commit was found to be incorrect for the reasons
below, so it must be reverted. It will be fixed up "correctly" in a
later kernel change.

The original commit was incorrect, it should have never have used
"unlikely()" and if it ever does trigger, resources are left grabbed.

Given there are no users for this code around, I'll just revert this and
leave it "as is" as the odds that ioremap() will ever fail here is
horrendiously low.

Cc: Kangjie Lu <kjlu@xxxxxxx>
Cc: David S. Miller <davem@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20210503115736.2104747-41-gregkh@xxxxxxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/isdn/hardware/mISDN/mISDNinfineon.c | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/drivers/isdn/hardware/mISDN/mISDNinfineon.c b/drivers/isdn/hardware/mISDN/mISDNinfineon.c
index a16c7a2a7f3d..fa9c491f9c38 100644
--- a/drivers/isdn/hardware/mISDN/mISDNinfineon.c
+++ b/drivers/isdn/hardware/mISDN/mISDNinfineon.c
@@ -697,11 +697,8 @@ setup_io(struct inf_hw *hw)
(ulong)hw->addr.start, (ulong)hw->addr.size);
return err;
}
- if (hw->ci->addr_mode == AM_MEMIO) {
+ if (hw->ci->addr_mode == AM_MEMIO)
hw->addr.p = ioremap(hw->addr.start, hw->addr.size);
- if (unlikely(!hw->addr.p))
- return -ENOMEM;
- }
hw->addr.mode = hw->ci->addr_mode;
if (debug & DEBUG_HW)
pr_notice("%s: IO addr %lx (%lu bytes) mode%d\n",
--
2.30.2