[PATCH iproute2] ss: fix NULL dereference when rendering without header
flat view
STALE3159d
From: Jean-Philippe Brucker <hidden>
Date: 2018-03-03 17:01:48
Subsystem:
the rest · Maintainer:
Linus Torvalds
When ss is invoked with the no-header flag, if the query doesn't return any result, render() is called with 'buffer' uninitialized. This currently leads to a segfault. Ensure that buffer is initialized before rendering. The bug can be triggered with: ss -H sport = 100000 Signed-off-by: Jean-Philippe Brucker <redacted> --- misc/ss.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/misc/ss.c b/misc/ss.c
index e047f9c0..e087bef7 100644
--- a/misc/ss.c
+++ b/misc/ss.c@@ -1197,10 +1197,15 @@ newline: /* Render buffered output with spacing and delimiters, then free up buffers */ static void render(int screen_width) { - struct buf_token *token = (struct buf_token *)buffer.head->data; + struct buf_token *token; int printed, line_started = 0; struct column *f; + if (!buffer.head) + return; + + token = (struct buf_token *)buffer.head->data; + /* Ensure end alignment of last token, it wasn't necessarily flushed */ buffer.tail->end += buffer.cur->len % 2;
--
2.16.2