summaryrefslogtreecommitdiff
path: root/fs
diff options
context:
space:
mode:
authorJeff Moyer <jmoyer@redhat.com>2018-12-11 12:37:49 -0500
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-12-21 14:13:04 +0100
commit5f4610fe2ed4351b45c0d82b3246f18b886d26f9 (patch)
treefd1e6aad9e958bab770e26192d17a9c96fe58924 /fs
parent7ff0bcb2cb31602dd347b216f5f70851102d5067 (diff)
aio: fix spectre gadget in lookup_ioctx
commit a538e3ff9dabcdf6c3f477a373c629213d1c3066 upstream. Matthew pointed out that the ioctx_table is susceptible to spectre v1, because the index can be controlled by an attacker. The below patch should mitigate the attack for all of the aio system calls. Cc: stable@vger.kernel.org Reported-by: Matthew Wilcox <willy@infradead.org> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs')
-rw-r--r--fs/aio.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/fs/aio.c b/fs/aio.c
index 3a749c3a92e3..a2de58f77338 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -43,6 +43,7 @@
#include <asm/kmap_types.h>
#include <linux/uaccess.h>
+#include <linux/nospec.h>
#include "internal.h"
@@ -1084,6 +1085,7 @@ static struct kioctx *lookup_ioctx(unsigned long ctx_id)
if (!table || id >= table->nr)
goto out;
+ id = array_index_nospec(id, table->nr);
ctx = rcu_dereference(table->table[id]);
if (ctx && ctx->user_id == ctx_id) {
if (percpu_ref_tryget_live(&ctx->users))