diff options
| author | Matthew Bobrowski <repnop@google.com> | 2021-08-08 15:25:05 +1000 |
|---|---|---|
| committer | Jan Kara <jack@suse.cz> | 2021-08-10 12:53:07 +0200 |
| commit | 490b9ba881e2c6337bb09b68010803ae98e59f4a (patch) | |
| tree | 3e8d42bb78fb4849c495567b04c70516a6cb8b7f | |
| parent | c576e0fcd6188d0edb50b0fb83f853433ef4819b (diff) | |
kernel/pid.c: implement additional checks upon pidfd_create() parameters
By adding the pidfd_create() declaration to linux/pid.h, we
effectively expose this function to the rest of the kernel. In order
to avoid any unintended behavior, or set false expectations upon this
function, ensure that constraints are forced upon each of the passed
parameters. This includes the checking of whether the passed struct
pid is a thread-group leader as pidfd creation is currently limited to
such pid types.
Link: https://lore.kernel.org/r/2e9b91c2d529d52a003b8b86c45f866153be9eb5.1628398044.git.repnop@google.com
Signed-off-by: Matthew Bobrowski <repnop@google.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Jan Kara <jack@suse.cz>
| -rw-r--r-- | kernel/pid.c | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/kernel/pid.c b/kernel/pid.c index d3cd95b8b080..efe87db44683 100644 --- a/kernel/pid.c +++ b/kernel/pid.c @@ -559,6 +559,12 @@ int pidfd_create(struct pid *pid, unsigned int flags) { int fd; + if (!pid || !pid_has_task(pid, PIDTYPE_TGID)) + return -EINVAL; + + if (flags & ~(O_NONBLOCK | O_RDWR | O_CLOEXEC)) + return -EINVAL; + fd = anon_inode_getfd("[pidfd]", &pidfd_fops, get_pid(pid), flags | O_RDWR | O_CLOEXEC); if (fd < 0) @@ -598,10 +604,7 @@ SYSCALL_DEFINE2(pidfd_open, pid_t, pid, unsigned int, flags) if (!p) return -ESRCH; - if (pid_has_task(p, PIDTYPE_TGID)) - fd = pidfd_create(p, flags); - else - fd = -EINVAL; + fd = pidfd_create(p, flags); put_pid(p); return fd; |