diff options
| author | Lee Jones <lee@kernel.org> | 2022-09-12 14:38:55 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-10-26 13:19:25 +0200 |
| commit | e4b17b461c992c30e594d24357a44951cf3cdc18 (patch) | |
| tree | a0dae2a4b42ae0afdb244fdef6032d7a31581af2 | |
| parent | aed374b4729b37dd6a6280b69f1277d9494b15d2 (diff) | |
| download | linux-stable-e4b17b461c992c30e594d24357a44951cf3cdc18.tar.gz linux-stable-e4b17b461c992c30e594d24357a44951cf3cdc18.tar.bz2 linux-stable-e4b17b461c992c30e594d24357a44951cf3cdc18.zip | |
bpf: Ensure correct locking around vulnerable function find_vpid()
[ Upstream commit 83c10cc362d91c0d8d25e60779ee52fdbbf3894d ]
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
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -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 e940c1f65938..02e5bdb82a9a 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -2325,7 +2325,9 @@ 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; |