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authorTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>2018-05-26 09:59:36 +0900
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-07-17 11:31:46 +0200
commita4ae35d6789d187e2763db87fee4d118c576f907 (patch)
tree06319644b49f4cb9bb183fedbde707cc6bb8dbff
parent2250809623141f969531692c2629dffd463dbaa6 (diff)
PM / hibernate: Fix oops at snapshot_write()
commit fc14eebfc20854a38fd9f1d93a42b1783dad4d17 upstream. syzbot is reporting NULL pointer dereference at snapshot_write() [1]. This is because data->handle is zero-cleared by ioctl(SNAPSHOT_FREE). Fix this by checking data_of(data->handle) != NULL before using it. [1] https://syzkaller.appspot.com/bug?id=828a3c71bd344a6de8b6a31233d51a72099f27fd Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Reported-by: syzbot <syzbot+ae590932da6e45d6564d@syzkaller.appspotmail.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--kernel/power/user.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/kernel/power/user.c b/kernel/power/user.c
index 526e8911460a..f83c1876b39c 100644
--- a/kernel/power/user.c
+++ b/kernel/power/user.c
@@ -184,6 +184,11 @@ static ssize_t snapshot_write(struct file *filp, const char __user *buf,
res = PAGE_SIZE - pg_offp;
}
+ if (!data_of(data->handle)) {
+ res = -EINVAL;
+ goto unlock;
+ }
+
res = simple_write_to_buffer(data_of(data->handle), res, &pg_offp,
buf, count);
if (res > 0)