2.6.32-longterm review patch. If anyone has any objections, please let me know.
------------------ From: Xiaotian Feng <[email protected]> commit 00bff392c81e4fb1901e5160fdd5afdb2546a6ab upstream. The current tty_audit_add_data code: do { size_t run; run = N_TTY_BUF_SIZE - buf->valid; if (run > size) run = size; memcpy(buf->data + buf->valid, data, run); buf->valid += run; data += run; size -= run; if (buf->valid == N_TTY_BUF_SIZE) tty_audit_buf_push_current(buf); } while (size != 0); If the current buffer is full, kernel will then call tty_audit_buf_push_current to empty the buffer. But if we disabled audit at the same time, tty_audit_buf_push() returns immediately if audit_enabled is zero. Without emptying the buffer. With obvious effect on tty_audit_add_data() that ends up spinning in that loop, copying 0 bytes at each iteration and attempting to push each time without any effect. Holding the lock all along. Suggested-by: Alexander Viro <[email protected]> Signed-off-by: Xiaotian Feng <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> Signed-off-by: Willy Tarreau <[email protected]> --- drivers/char/tty_audit.c | 4 +++- 1 files changed, 3 insertions(+), 1 deletions(-) diff --git a/drivers/char/tty_audit.c b/drivers/char/tty_audit.c index ac16fbe..dd4691a 100644 --- a/drivers/char/tty_audit.c +++ b/drivers/char/tty_audit.c @@ -94,8 +94,10 @@ static void tty_audit_buf_push(struct task_struct *tsk, uid_t loginuid, { if (buf->valid == 0) return; - if (audit_enabled == 0) + if (audit_enabled == 0) { + buf->valid = 0; return; + } tty_audit_log("tty", tsk, loginuid, sessionid, buf->major, buf->minor, buf->data, buf->valid); buf->valid = 0; -- 1.7.2.1.45.g54fbc -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
