diff options
| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2018-10-16 12:59:44 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-11-27 16:08:02 +0100 |
| commit | b61865ef9b88adc09188f736b590e54602410ed3 (patch) | |
| tree | cc159f2e54b812af875a25d3535c701e2c9bf276 | |
| parent | 1b44cb3b63f1b745d6e8e4e382b0131d9d2b480a (diff) | |
drivers/misc/sgi-gru: fix Spectre v1 vulnerability
commit fee05f455ceb5c670cbe48e2f9454ebc4a388554 upstream.
req.gid 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:
vers/misc/sgi-gru/grukdump.c:200 gru_dump_chiplet_request() warn:
potential spectre issue 'gru_base' [w]
Fix this by sanitizing req.gid before calling macro GID_TO_GRU, which
uses it to index gru_base.
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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/misc/sgi-gru/grukdump.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/misc/sgi-gru/grukdump.c b/drivers/misc/sgi-gru/grukdump.c index 313da3150262..1540a7785e14 100644 --- a/drivers/misc/sgi-gru/grukdump.c +++ b/drivers/misc/sgi-gru/grukdump.c @@ -27,6 +27,9 @@ #include <linux/delay.h> #include <linux/bitops.h> #include <asm/uv/uv_hub.h> + +#include <linux/nospec.h> + #include "gru.h" #include "grutables.h" #include "gruhandles.h" @@ -196,6 +199,7 @@ int gru_dump_chiplet_request(unsigned long arg) /* Currently, only dump by gid is implemented */ if (req.gid >= gru_max_gids) return -EINVAL; + req.gid = array_index_nospec(req.gid, gru_max_gids); gru = GID_TO_GRU(req.gid); ubuf = req.buf; |