diff options
| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2018-10-16 16:32:40 +0200 |
|---|---|---|
| committer | Doug Ledford <dledford@redhat.com> | 2018-10-16 17:32:40 +0200 |
| commit | 0295e39595e1146522f2722715dba7f7fba42217 (patch) | |
| tree | 705287d26046659b333c3d1fb06612f94d319584 /drivers | |
| parent | IB/mlx5: Unmap DMA addr from HCA before IOMMU (diff) | |
| download | linux-0295e39595e1146522f2722715dba7f7fba42217.tar.xz linux-0295e39595e1146522f2722715dba7f7fba42217.zip | |
IB/ucm: Fix Spectre v1 vulnerability
hdr.cmd can be indirectly controlled by user-space, hence leading to
a potential exploitation of the Spectre variant 1 vulnerability.
This issue was detected with the help of Smatch:
drivers/infiniband/core/ucm.c:1127 ib_ucm_write() warn: potential
spectre issue 'ucm_cmd_table' [r] (local cap)
Fix this by sanitizing hdr.cmd before using it to index
ucm_cmd_table.
Notice that given that speculation windows are large, the policy is
to kill the speculation on the first load and not worry if it can be
completed with a dependent load/store [1].
[1] https://marc.info/?l=linux-kernel&m=152449131114778&w=2
Cc: stable@vger.kernel.org
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/infiniband/core/ucm.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/infiniband/core/ucm.c b/drivers/infiniband/core/ucm.c index faa9e6116b2f..73332b9a25b5 100644 --- a/drivers/infiniband/core/ucm.c +++ b/drivers/infiniband/core/ucm.c @@ -46,6 +46,8 @@ #include <linux/mutex.h> #include <linux/slab.h> +#include <linux/nospec.h> + #include <linux/uaccess.h> #include <rdma/ib.h> @@ -1120,6 +1122,7 @@ static ssize_t ib_ucm_write(struct file *filp, const char __user *buf, if (hdr.cmd >= ARRAY_SIZE(ucm_cmd_table)) return -EINVAL; + hdr.cmd = array_index_nospec(hdr.cmd, ARRAY_SIZE(ucm_cmd_table)); if (hdr.in + sizeof(hdr) > len) return -EINVAL; |