diff options
| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2018-10-16 16:32:40 +0200 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2018-12-16 22:09:41 +0000 |
| commit | bc500cd4b469ef37d167f24025f62d4ed87372b8 (patch) | |
| tree | 54c253327b88b6c8ec13bffdf49befc611b2a07c | |
| parent | e8a72e62937362e35c36efefcdd513562ee81842 (diff) | |
| download | linux-bc500cd4b469ef37d167f24025f62d4ed87372b8.tar.gz linux-bc500cd4b469ef37d167f24025f62d4ed87372b8.tar.bz2 linux-bc500cd4b469ef37d167f24025f62d4ed87372b8.zip | |
IB/ucm: Fix Spectre v1 vulnerability
commit 0295e39595e1146522f2722715dba7f7fba42217 upstream.
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
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
| -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 5befec118a18..23b72417a433 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 <asm/uaccess.h> #include <rdma/ib.h> @@ -1116,6 +1118,7 @@ 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; |