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| author |   Gustavo A. R. Silva <gustavo@embeddedor.com> | 2018-10-16 16:59:01 +0200 |
|---|---|---|
| committer |   Doug Ledford <dledford@redhat.com> | 2018-10-16 12:47:40 -0400 |
| commit | a3671a4f973ee9d9621d60166cc3b037c397d604 (patch) | |
| tree | ef3c0975d7284a25fd265d63793c5edcee2d322f /drivers/infiniband/core/ucma.c | |
| parent | IB/ucm: Fix Spectre v1 vulnerability (diff) | |
| download | linux-dev-a3671a4f973ee9d9621d60166cc3b037c397d604.tar.xz linux-dev-a3671a4f973ee9d9621d60166cc3b037c397d604.zip | |
RDMA/ucma: 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/ucma.c:1686 ucma_write() warn: potential
spectre issue 'ucma_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/infiniband/core/ucma.c')
| -rw-r--r-- | drivers/infiniband/core/ucma.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/infiniband/core/ucma.c b/drivers/infiniband/core/ucma.c index 21863ddde63e..01d68ed46c1b 100644 --- a/drivers/infiniband/core/ucma.c +++ b/drivers/infiniband/core/ucma.c @@ -44,6 +44,8 @@ #include <linux/module.h> #include <linux/nsproxy.h> +#include <linux/nospec.h> + #include <rdma/rdma_user_cm.h> #include <rdma/ib_marshall.h> #include <rdma/rdma_cm.h> @@ -1676,6 +1678,7 @@ static ssize_t ucma_write(struct file *filp, const char __user *buf, if (hdr.cmd >= ARRAY_SIZE(ucma_cmd_table)) return -EINVAL; + hdr.cmd = array_index_nospec(hdr.cmd, ARRAY_SIZE(ucma_cmd_table)); if (hdr.in + sizeof(hdr) > len) return -EINVAL; |