diff options
| author | Beau Belgrave <beaub@linux.microsoft.com> | 2023-04-26 00:51:04 +0200 |
|---|---|---|
| committer | Steven Rostedt (Google) <rostedt@goodmis.org> | 2023-04-26 03:03:46 +0200 |
| commit | cd98c93286a30cc4588dfd02453bec63c2f4acf4 (patch) | |
| tree | 7bb663ac6965bdb99ddacaace92b5f52aebfbe2f /kernel | |
| parent | seq_buf: Add seq_buf_do_printk() helper (diff) | |
| download | linux-cd98c93286a30cc4588dfd02453bec63c2f4acf4.tar.xz linux-cd98c93286a30cc4588dfd02453bec63c2f4acf4.zip | |
tracing/user_events: Ensure write index cannot be negative
The write index indicates which event the data is for and accesses a
per-file array. The index is passed by user processes during write()
calls as the first 4 bytes. Ensure that it cannot be negative by
returning -EINVAL to prevent out of bounds accesses.
Update ftrace self-test to ensure this occurs properly.
Link: https://lkml.kernel.org/r/20230425225107.8525-2-beaub@linux.microsoft.com
Fixes: 7f5a08c79df3 ("user_events: Add minimal support for trace_event into ftrace")
Reported-by: Doug Cook <dcook@linux.microsoft.com>
Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/trace/trace_events_user.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/kernel/trace/trace_events_user.c b/kernel/trace/trace_events_user.c index eadb58a3efba..546d47a57520 100644 --- a/kernel/trace/trace_events_user.c +++ b/kernel/trace/trace_events_user.c @@ -1824,6 +1824,9 @@ static ssize_t user_events_write_core(struct file *file, struct iov_iter *i) if (unlikely(copy_from_iter(&idx, sizeof(idx), i) != sizeof(idx))) return -EFAULT; + if (idx < 0) + return -EINVAL; + rcu_read_lock_sched(); refs = rcu_dereference_sched(info->refs); |