From b7c5dc73e192b5c97edc165c2f7023d8559d6264 Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Tue, 25 Feb 2020 19:20:56 +0300 Subject: [PATCH] libnvdimm: Out of bounds read in __nd_ioctl() [ Upstream commit f84afbdd3a9e5e10633695677b95422572f920dc ] The "cmd" comes from the user and it can be up to 255. It it's more than the number of bits in long, it results out of bounds read when we check test_bit(cmd, &cmd_mask). The highest valid value for "cmd" is ND_CMD_CALL (10) so I added a compare against that. Fixes: 62232e45f4a2 ("libnvdimm: control (ioctl) messages for nvdimm_bus and nvdimm devices") Signed-off-by: Dan Carpenter Link: https://lore.kernel.org/r/20200225162055.amtosfy7m35aivxg@kili.mountain Signed-off-by: Dan Williams Signed-off-by: Sasha Levin --- drivers/nvdimm/bus.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/nvdimm/bus.c b/drivers/nvdimm/bus.c index 54a633e8cb5d..48a070a37ea9 100644 --- a/drivers/nvdimm/bus.c +++ b/drivers/nvdimm/bus.c @@ -984,8 +984,10 @@ static int __nd_ioctl(struct nvdimm_bus *nvdimm_bus, struct nvdimm *nvdimm, return -EFAULT; } - if (!desc || (desc->out_num + desc->in_num == 0) || - !test_bit(cmd, &cmd_mask)) + if (!desc || + (desc->out_num + desc->in_num == 0) || + cmd > ND_CMD_CALL || + !test_bit(cmd, &cmd_mask)) return -ENOTTY; /* fail write commands (when read-only) */