proxmox-mirrors/mirror_ubuntu-kernels
1
0
Fork 0
mirror of https://git.proxmox.com/git/mirror_ubuntu-kernels.git synced 2025-12-30 22:27:06 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

tracing/user_events: Ensure write index cannot be negative

Browse Source 
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: 7f5a08c79d ("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>
This commit is contained in:
Beau Belgrave 2023-04-25 15:51:04 -07:00 committed by Steven Rostedt (Google)
parent 96928d9032
commit cd98c93286
2 changed files with 8 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
kernel/trace/trace_events_user.c
View File

@ -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);

5
tools/testing/selftests/user_events/ftrace_test.c
View File

@ -296,6 +296,11 @@ TEST_F(user, write_events) {
ASSERT_NE(-1, writev(self->data_fd, (const struct iovec *)io, 3));
after = trace_bytes();
ASSERT_GT(after, before);
/* Negative index should fail with EINVAL */
reg.write_index = -1;
ASSERT_EQ(-1, writev(self->data_fd, (const struct iovec *)io, 3));
ASSERT_EQ(EINVAL, errno);
}
TEST_F(user, write_fault) {