| Message ID | 1527296376-3540-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp (mailing list archive) |
|---|---|
| State | Mainlined |
| Delegated to: | Rafael Wysocki |
| Headers | show |
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!
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)
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(+)