From 436af737c3c2831dd0505a6a1247b1ec0d8f6375 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 d47412dcdf38..5e5c6aafc070 100644 --- a/drivers/nvdimm/bus.c +++ b/drivers/nvdimm/bus.c @@ -1010,8 +1010,10 @@ 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) */