mbox: Don't crash if >=8192 bytes long line begins with "From ".

--HG--
branch : HEAD

diff --git a/src/lib-storage/index/mbox/istream-raw-mbox.c b/src/lib-storage/index/mbox/istream-raw-mbox.c
index cc6538f7139f0ea238e38193903fbfe42faac438..10285628232cf9d9353aa51283bc88fdcf32df64 100644 (file)
--- a/src/lib-storage/index/mbox/istream-raw-mbox.c
+++ b/src/lib-storage/index/mbox/istream-raw-mbox.c
@@ -53,19 +53,32 @@ static int mbox_read_from_line(struct raw_mbox_istream *rstream)
        char *sender;
        time_t received_time;
        size_t pos, line_pos;
-       int skip, tz;
+       ssize_t ret;
+       unsigned int skip;
+       int tz;
 
        buf = i_stream_get_data(rstream->istream.parent, &pos);
        i_assert(pos > 0);
 
        /* from_offset points to "\nFrom ", so unless we're at the beginning
           of the file, skip the initial \n */
-       skip = rstream->from_offset != 0;
-       if (skip && *buf == '\r')
-               skip++;
+       if (rstream->from_offset == 0)
+               skip = 0;
+       else {
+               skip = 1;
+               if (*buf == '\r')
+                       skip++;
+       }
 
        while ((p = memchr(buf+skip, '\n', pos-skip)) == NULL) {
-               if (i_stream_read(rstream->istream.parent) < 0) {
+               ret = i_stream_read(rstream->istream.parent);
+               buf = i_stream_get_data(rstream->istream.parent, &pos);
+               if (ret < 0) {
+                       if (ret == -2) {
+                               /* From_-line is too long, but we should be
+                                  able to parse what we have so far. */
+                               break;
+                       }
                        /* EOF shouldn't happen */
                        rstream->istream.istream.eof =
                                rstream->istream.parent->eof;
@@ -73,19 +86,14 @@ static int mbox_read_from_line(struct raw_mbox_istream *rstream)
                                rstream->istream.parent->stream_errno;
                        return -1;
                }
-               buf = i_stream_get_data(rstream->istream.parent, &pos);
                i_assert(pos > 0);
        }
-       line_pos = (size_t)(p - buf);
-
-       if (rstream->from_offset != 0) {
-               buf += skip;
-               pos -= skip;
-       }
+       line_pos = p == NULL ? 0 : (size_t)(p - buf);
 
        /* beginning of mbox */
-       if (memcmp(buf, "From ", 5) != 0 ||
-           mbox_from_parse(buf+5, pos-5, &received_time, &tz, &sender) < 0) {
+       if (memcmp(buf+skip, "From ", 5) != 0 ||
+           mbox_from_parse((buf+skip)+5, (pos-skip)-5,
+                           &received_time, &tz, &sender) < 0) {
                /* broken From - should happen only at beginning of
                   file if this isn't a mbox.. */
                rstream->istream.istream.stream_errno = EINVAL;
@@ -102,9 +110,33 @@ static int mbox_read_from_line(struct raw_mbox_istream *rstream)
                rstream->next_sender = sender;
        }
 
-       /* we'll skip over From-line */
+       /* skip over From-line */
+       if (line_pos == 0) {
+               /* line was too long. skip the input until we find LF. */
+               rstream->istream.istream.v_offset += pos;
+               i_stream_skip(rstream->istream.parent, pos);
+
+               while ((ret = i_stream_read(rstream->istream.parent)) > 0) {
+                       p = memchr(buf, '\n', pos);
+                       if (p != NULL)
+                               break;
+                       rstream->istream.istream.v_offset += pos;
+                       i_stream_skip(rstream->istream.parent, pos);
+               }
+               if (ret <= 0) {
+                       i_assert(ret == -1);
+                       /* EOF shouldn't happen */
+                       rstream->istream.istream.eof =
+                               rstream->istream.parent->eof;
+                       rstream->istream.istream.stream_errno =
+                               rstream->istream.parent->stream_errno;
+                       return -1;
+               }
+               line_pos = (size_t)(p - buf);
+       }
        rstream->istream.istream.v_offset += line_pos+1;
        i_stream_skip(rstream->istream.parent, line_pos+1);
+
        rstream->hdr_offset = rstream->istream.istream.v_offset;
        return 0;
 }
@@ -181,8 +213,11 @@ static ssize_t i_stream_raw_mbox_read(struct istream_private *stream)
 
        if (ret < 0) {
                if (ret == -2) {
-                       if (stream->istream.v_offset + pos ==
-                           rstream->input_peak_offset) {
+                       if (stream->skip == stream->pos) {
+                               /* From_-line is longer than our input buffer.
+                                  finish the check without seeing the LF. */
+                       } else if (stream->istream.v_offset + pos ==
+                                  rstream->input_peak_offset) {
                                /* we've read everything our parent stream
                                   has to offer. */
                                stream->buffer = buf;
@@ -258,9 +293,7 @@ static ssize_t i_stream_raw_mbox_read(struct istream_private *stream)
                if (buf[i] == *fromp) {
                        if (*++fromp == '\0') {
                                /* potential From-line, see if we have the
-                                  rest of the line buffered.
-                                  FIXME: if From-line is longer than input
-                                  buffer, we break. probably irrelevant.. */
+                                  rest of the line buffered. */
                                i++;
                                if (rstream->hdr_offset + rstream->mail_size ==
                                    stream->istream.v_offset + i - 6 ||
@@ -275,11 +308,18 @@ static ssize_t i_stream_raw_mbox_read(struct istream_private *stream)
                                        } else {
                                                crlf_ending = FALSE;
                                        }
+                                       if (ret == -2) {
+                                               /* even if we don't have the
+                                                  whole line, we need to
+                                                  finish this check now. */
+                                               goto mbox_verify;
+                                       }
                                }
                                fromp = mbox_from;
                        } else if (from_start_pos != (size_t)-1) {
                                /* we have the whole From-line here now.
                                   See if it's a valid one. */
+                       mbox_verify:
                                if (mbox_from_parse(buf + from_after_pos,
                                                    pos - from_after_pos,
                                                    &received_time, &tz,