diff options
| author | Suren Baghdasaryan <surenb@google.com> | 2020-02-03 13:22:16 -0800 |
|---|---|---|
| committer | Todd Kjos <tkjos@google.com> | 2020-05-01 16:57:33 -0700 |
| commit | f850f1c9f06a748cb91e75107f8dbebd5adb1981 (patch) | |
| tree | eaaaa3d1674f0905c3e3fbd1b40f5d758cd6b4d6 | |
| parent | d5ab0f8500027cdc11efb1a2d655718a81fb9cc7 (diff) | |
UPSTREAM: sched/psi: Fix OOB write when writing 0 bytes to PSI filesASB-2020-05-05_4.14-q-release
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
(cherry picked from commit 6fcca0fa48118e6d63733eb4644c6cd880c15b8f)
Bug: 148159562
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Change-Id: I9ec7acfc6e1083c677a95b0ea1c559ab50152873
| -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 eb6500b81626..ea452f04a53c 100644 --- a/kernel/sched/psi.c +++ b/kernel/sched/psi.c @@ -1191,6 +1191,9 @@ 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) - 1)); if (copy_from_user(buf, user_buf, buf_size)) return -EFAULT; |