diff options
author | Peter Hurley <peter@hurleysoftware.com> | 2016-01-10 09:55:30 +0300 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-01-28 03:41:04 +0300 |
commit | b50819f437c094b4beb2e8684fbe12bbe79fb331 (patch) | |
tree | 2b039e0871315df7711346116f571ede03e39012 /drivers/tty/tty_audit.c | |
parent | f229c2c161de94a404fa16a17cb93c4a06938af5 (diff) |
tty: audit: Ignore current association for audit push
In canonical read mode, each line read and logged is pushed separately
with tty_audit_push(). For all single-threaded processes and multi-threaded
processes reading from only one tty, this patch has no effect; the last line
read will still be the entry pushed to the audit log because the tty
association cannot have changed between tty_audit_add_data() and
tty_audit_push().
For multi-threaded processes reading from different ttys concurrently,
the audit log will have mixed log entries anyway. Consider two ttys
audited concurrently:
CPU0 CPU1
---------- ------------
tty_audit_add_data(ttyA)
tty_audit_add_data(ttyB)
tty_audit_push()
tty_audit_add_data(ttyB)
tty_audit_push()
This patch will now cause the ttyB output to be split into separate
audit log entries.
However, this possibility is equally likely without this patch:
CPU0 CPU1
---------- ------------
tty_audit_add_data(ttyB)
tty_audit_add_data(ttyA)
tty_audit_push()
tty_audit_add_data(ttyB)
tty_audit_push()
Mixed canonical and non-canonical reads have similar races.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/tty_audit.c')
-rw-r--r-- | drivers/tty/tty_audit.c | 11 |
1 files changed, 3 insertions, 8 deletions
diff --git a/drivers/tty/tty_audit.c b/drivers/tty/tty_audit.c index 5f65653cee48..5ae48396e265 100644 --- a/drivers/tty/tty_audit.c +++ b/drivers/tty/tty_audit.c @@ -313,9 +313,9 @@ void tty_audit_add_data(struct tty_struct *tty, const void *data, size_t size) /** * tty_audit_push - Push buffered data out * - * Make sure no audit data is pending for @tty on the current process. + * Make sure no audit data is pending on the current process. */ -void tty_audit_push(struct tty_struct *tty) +void tty_audit_push(void) { struct tty_audit_buf *buf; unsigned long flags; @@ -331,13 +331,8 @@ void tty_audit_push(struct tty_struct *tty) spin_unlock_irqrestore(¤t->sighand->siglock, flags); if (buf) { - int major, minor; - - major = tty->driver->major; - minor = tty->driver->minor_start + tty->index; mutex_lock(&buf->mutex); - if (buf->major == major && buf->minor == minor) - tty_audit_buf_push(buf); + tty_audit_buf_push(buf); mutex_unlock(&buf->mutex); tty_audit_buf_put(buf); } |