diff options
| author | Beau Belgrave | 2023-04-25 15:51:04 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman | 2023-05-11 23:03:32 +0900 |
| commit | 0489c2b2c3104b89f078dbcec8c744dfc157d3e9 (patch) | |
| tree | 1ea6ff33590f5022f19bba3fda1cce1eddc0f933 /kernel | |
| parent | 6472a6d0c79826256bfa3a6b45710dd499a984bf (diff) | |
tracing/user_events: Ensure write index cannot be negative
[ Upstream commit cd98c93286a30cc4588dfd02453bec63c2f4acf4 ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.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 908e8a13c675..625cab4b9d94 100644 --- a/kernel/trace/trace_events_user.c +++ b/kernel/trace/trace_events_user.c @@ -1398,6 +1398,9 @@ 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); |