path: root/vcs-svn
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authorJonathan Nieder <>2011-05-27 09:07:44 (GMT)
committerJonathan Nieder <>2011-06-15 07:15:22 (GMT)
commitfbdd4f6fb477885e4bf81658e02c3542a861c695 (patch)
tree4284cbc220ef15c28474e3203448fd60397c68d5 /vcs-svn
parentb747e5675db5e26292c942146a25e1c26440c5f7 (diff)
vcs-svn: cap number of bytes read from sliding view
Introduce a "max_off" field in struct sliding_view, roughly representing a maximum number of bytes that can be read from "file". If it is set to a nonnegative integer, a call to move_window() attempting to put the right endpoint beyond that offset will return an error instead. The idea is to use this when applying Subversion-format deltas to prevent reads past the end of the preimage (which has known length). Without such a check, corrupt deltas would cause svn-fe to block indefinitely when data in the input pipe is exhausted. Inspired-by: Ramkumar Ramachandra <> Signed-off-by: Jonathan Nieder <>
Diffstat (limited to 'vcs-svn')
2 files changed, 4 insertions, 1 deletions
diff --git a/vcs-svn/sliding_window.c b/vcs-svn/sliding_window.c
index 1b8d987..1bac7a4 100644
--- a/vcs-svn/sliding_window.c
+++ b/vcs-svn/sliding_window.c
@@ -54,6 +54,8 @@ int move_window(struct sliding_view *view, off_t off, size_t width)
return -1;
if (off < view->off || off + width < view->off + view->width)
return error("invalid delta: window slides left");
+ if (view->max_off >= 0 && view->max_off < off + width)
+ return error("delta preimage ends early");
file_offset = view->off + view->buf.len;
if (off < file_offset) {
diff --git a/vcs-svn/sliding_window.h b/vcs-svn/sliding_window.h
index ed0bfdd..b43a825 100644
--- a/vcs-svn/sliding_window.h
+++ b/vcs-svn/sliding_window.h
@@ -7,10 +7,11 @@ struct sliding_view {
struct line_buffer *file;
off_t off;
size_t width;
+ off_t max_off; /* -1 means unlimited */
struct strbuf buf;
-#define SLIDING_VIEW_INIT(input) { (input), 0, 0, STRBUF_INIT }
+#define SLIDING_VIEW_INIT(input, len) { (input), 0, 0, (len), STRBUF_INIT }
extern int move_window(struct sliding_view *view, off_t off, size_t width);