diff options
| author | Lee Jones <lee@kernel.org> | 2022-09-12 16:38:55 +0300 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2022-09-16 19:00:52 +0300 |
| commit | 83c10cc362d91c0d8d25e60779ee52fdbbf3894d (patch) | |
| tree | 98b9cf773986ab7052dd7874ddb663d07dc2dd25 /kernel/bpf/syscall.c | |
| parent | a37a32583e282d8d815e22add29bc1e91e19951a (diff) | |
| download | linux-83c10cc362d91c0d8d25e60779ee52fdbbf3894d.tar.xz | |
bpf: Ensure correct locking around vulnerable function find_vpid()
The documentation for find_vpid() clearly states:
"Must be called with the tasklist_lock or rcu_read_lock() held."
Presently we do neither for find_vpid() instance in bpf_task_fd_query().
Add proper rcu_read_lock/unlock() to fix the issue.
Fixes: 41bdc4b40ed6f ("bpf: introduce bpf subcommand BPF_TASK_FD_QUERY")
Signed-off-by: Lee Jones <lee@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20220912133855.1218900-1-lee@kernel.org
Diffstat (limited to 'kernel/bpf/syscall.c')
| -rw-r--r-- | kernel/bpf/syscall.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 27760627370d..1bd18af8af83 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -4395,7 +4395,9 @@ static int bpf_task_fd_query(const union bpf_attr *attr, if (attr->task_fd_query.flags != 0) return -EINVAL; + rcu_read_lock(); task = get_pid_task(find_vpid(pid), PIDTYPE_PID); + rcu_read_unlock(); if (!task) return -ENOENT; |