Messages in this thread Patch in this message | | | From | Vincent Whitchurch <> | Subject | [PATCH v2] tty: Fix lookahead_buf crash with serdev | Date | Thu, 18 Aug 2022 13:50:26 +0200 |
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Do not follow a NULL pointer if the tty_port_client_operations does not implement the ->lookahead_buf() callback, which is the case with serdev's ttyport.
Fixes: 6bb6fa6908ebd3 ("tty: Implement lookahead to process XON/XOFF timely") Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com> ---
Notes: v2: Move more stuff into if block.
drivers/tty/tty_buffer.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-)
diff --git a/drivers/tty/tty_buffer.c b/drivers/tty/tty_buffer.c index 9fdecc795b6b..5e287dedce01 100644 --- a/drivers/tty/tty_buffer.c +++ b/drivers/tty/tty_buffer.c @@ -470,7 +470,6 @@ static void lookahead_bufs(struct tty_port *port, struct tty_buffer *head) while (head) { struct tty_buffer *next; - unsigned char *p, *f = NULL; unsigned int count; /* @@ -489,11 +488,16 @@ static void lookahead_bufs(struct tty_port *port, struct tty_buffer *head) continue; } - p = char_buf_ptr(head, head->lookahead); - if (~head->flags & TTYB_NORMAL) - f = flag_buf_ptr(head, head->lookahead); + if (port->client_ops->lookahead_buf) { + unsigned char *p, *f = NULL; + + p = char_buf_ptr(head, head->lookahead); + if (~head->flags & TTYB_NORMAL) + f = flag_buf_ptr(head, head->lookahead); + + port->client_ops->lookahead_buf(port, p, f, count); + } - port->client_ops->lookahead_buf(port, p, f, count); head->lookahead += count; } } -- 2.34.1
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