diff options
| author | Suren Baghdasaryan <surenb@google.com> | 2020-02-03 13:22:16 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-02-28 17:22:21 +0100 |
| commit | e61c236dcf3416211008774b6c2bfa01753a82c1 (patch) | |
| tree | 2fa50fd3fee93f469a10f6f0ffe3788018273631 | |
| parent | 26ae0493c181e989fc1e339a92f703228bae4c0c (diff) | |
sched/psi: Fix OOB write when writing 0 bytes to PSI files
commit 6fcca0fa48118e6d63733eb4644c6cd880c15b8f upstream.
Issuing write() with count parameter set to 0 on any file under
/proc/pressure/ will cause an OOB write because of the access to
buf[buf_size-1] when NUL-termination is performed. Fix this by checking
for buf_size to be non-zero.
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Link: https://lkml.kernel.org/r/20200203212216.7076-1-surenb@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | kernel/sched/psi.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c index ce8f6748678a2..9154e745f0978 100644 --- a/kernel/sched/psi.c +++ b/kernel/sched/psi.c @@ -1199,6 +1199,9 @@ static ssize_t psi_write(struct file *file, const char __user *user_buf, if (static_branch_likely(&psi_disabled)) return -EOPNOTSUPP; + if (!nbytes) + return -EINVAL; + buf_size = min(nbytes, sizeof(buf)); if (copy_from_user(buf, user_buf, buf_size)) return -EFAULT; |