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| author | Beau Belgrave <beaub@linux.microsoft.com> | 2023-04-25 15:51:04 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-05-11 23:17:29 +0900 |
| commit | fa7f2f5d1739452280c22727c4384a52b72ab5de (patch) | |
| tree | 752b8b0366df310578c93ad3d5ef4f1ae8262f05 /kernel | |
| parent | a6a8b111f31dc53991882d60f8f5497e07220c89 (diff) | |
| download | linux-stable-fa7f2f5d1739452280c22727c4384a52b72ab5de.tar.gz linux-stable-fa7f2f5d1739452280c22727c4384a52b72ab5de.tar.bz2 linux-stable-fa7f2f5d1739452280c22727c4384a52b72ab5de.zip | |
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); |