[PATCH 5.5 304/399] cmd64x: potential buffer overflow in cmd64x_program_timings()

Greg Kroah-Hartman
2020-02-21T07:56:52Z

From: Dan Carpenter <dan.carpenter@oracle.com>

[ Upstream commit 117fcc3053606d8db5cef8821dca15022ae578bb ]

The "drive->dn" value is a u8 and it is controlled by root only, but
it could be out of bounds here so let's check.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/ide/cmd64x.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/ide/cmd64x.c b/drivers/ide/cmd64x.c
index a1898e11b04e6..943bf944bf722 100644
--- a/drivers/ide/cmd64x.c
+++ b/drivers/ide/cmd64x.c
@@ -66,6 +66,9 @@ static void cmd64x_program_timings(ide_drive_t *drive, u8 mode)
struct ide_timing t;
u8 arttim = 0;

+ if (drive->dn >= ARRAY_SIZE(drwtim_regs))
+ return;
+
ide_timing_compute(drive, mode, &t, T, 0);

/*
--
2.20.1