* [PATCH] PM / hibernate: Fix oops at snapshot_write().
@ 2018-05-26 0:59 Tetsuo Handa
2018-05-29 8:48 ` Rafael J. Wysocki
0 siblings, 1 reply; 2+ messages in thread
From: Tetsuo Handa @ 2018-05-26 0:59 UTC (permalink / raw)
To: Rafael J. Wysocki, Pavel Machek, Len Brown
Cc: linux-pm, linux-kernel, Tetsuo Handa, syzbot
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>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Len Brown <len.brown@intel.com>
Cc: Pavel Machek <pavel@ucw.cz>
---
kernel/power/user.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/kernel/power/user.c b/kernel/power/user.c
index 75c959d..abd2255 100644
--- a/kernel/power/user.c
+++ b/kernel/power/user.c
@@ -186,6 +186,11 @@ 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)
--
1.8.3.1
^ permalink raw reply related [flat|nested] 2+ messages in thread* Re: [PATCH] PM / hibernate: Fix oops at snapshot_write().
2018-05-26 0:59 [PATCH] PM / hibernate: Fix oops at snapshot_write() Tetsuo Handa
@ 2018-05-29 8:48 ` Rafael J. Wysocki
0 siblings, 0 replies; 2+ messages in thread
From: Rafael J. Wysocki @ 2018-05-29 8:48 UTC (permalink / raw)
To: Tetsuo Handa; +Cc: Pavel Machek, Len Brown, linux-pm, linux-kernel, syzbot
On Saturday, May 26, 2018 2:59:36 AM CEST Tetsuo Handa wrote:
> 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>
> Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
> Cc: Len Brown <len.brown@intel.com>
> Cc: Pavel Machek <pavel@ucw.cz>
> ---
> kernel/power/user.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/kernel/power/user.c b/kernel/power/user.c
> index 75c959d..abd2255 100644
> --- a/kernel/power/user.c
> +++ b/kernel/power/user.c
> @@ -186,6 +186,11 @@ 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)
>
Applied, thanks!
^ permalink raw reply [flat|nested] 2+ messages in thread
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