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| author | Lee Jones <lee@kernel.org> | 2022-09-12 16:38:55 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-10-24 10:57:11 +0300 |
| commit | 7de3297a9239dbcadd7c52eaab3b75cb6cf522e4 (patch) | |
| tree | 91b7105d2b232d4f12635db4777f9f5f3087df1c | |
| parent | 5ae7255b9ab3595ecfc4108269a7e5c0eeebb495 (diff) | |
| download | linux-7de3297a9239dbcadd7c52eaab3b75cb6cf522e4.tar.xz | |
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 7a3444988c84..494ba88054e8 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -4361,7 +4361,9 @@ 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; |