[PATCH 1/4] vcs-svn: make reading of properties binary-safe
- From
Jonathan Nieder <jrnieder@gmail.com>
- Date
- Mar 25, 2011, 04:07 UTC
- Message-ID
- <20110325040730.GB3007@elie>
- In-Reply-To
- <20110325033431.GA3007@elie>
A caller to buffer_read_string cannot easily tell the difference between the string "foo" followed by an early end of file and the string "foo\0bar\0baz". In a half-hearted attempt to catch early EOF, c9d1c8ba (2010-12-28) introduced a safety strlen(val) == len for property keys and values, to at least keep svn-fe from reading uninitialized data when a property list ends early due to EOF.
But it is permissible for both keys and values to contain null characters, so in handling revision 59151 of the ASF repository svn-fe encounters a null byte and produces the following message:
fatal: invalid dump: unexpected end of file
Fix it by using buffer_read_binary to read to a strbuf (and keep track of the actual length read). Most consumers of properties still use C-style strings, so in practice we still can't use an author or log message with embedded nuls, but at least this way svn-fe won't error out.
Reported-by: David Barr <david.barr@cordelta.com> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> --- t/t9010-svn-fe.sh | 27 +++++++++++++++++++++++++++ vcs-svn/svndump.c | 24 ++++++++++-------------- 2 files changed, 37 insertions(+), 14 deletions(-)
diff --git a/t/t9010-svn-fe.sh b/t/t9010-svn-fe.sh index 5a6a4b9..47f1e4f 100755 --- a/t/t9010-svn-fe.sh +++ b/t/t9010-svn-fe.sh @@ -370,6 +370,33 @@ test_expect_failure 'change file mode but keep old content' ' test_cmp hello actual.target ' +test_expect_success 'null byte in property value' ' + reinit_git && + echo "commit message" >expect.message && + { + properties \ + unimportant "something with a null byte (Q)" \ + svn:log "commit message"&& + echo PROPS-END + } | + q_to_nul >props && + { + cat <<-\EOF && + SVN-fs-dump-format-version: 3 + + Revision-number: 1 + EOF + echo Prop-content-length: $(wc -c <props) && + echo Content-length: $(wc -c <props) && + echo && + cat props + } >nullprop.dump && + test-svn-fe nullprop.dump >stream && + git fast-import <stream && + git diff-tree --always -s --format=%s HEAD >actual.message && + test_cmp expect.message actual.message +' + test_expect_success 'change file mode and reiterate content' ' reinit_git && cat >expect <<-\EOF && diff --git a/vcs-svn/svndump.c b/vcs-svn/svndump.c index ea5b128..c00f031 100644 --- a/vcs-svn/svndump.c +++ b/vcs-svn/svndump.c @@ -147,6 +147,7 @@ static void die_short_read(void) static void read_props(void) { static struct strbuf key = STRBUF_INIT; + static struct strbuf val = STRBUF_INIT; const char *t; /* * NEEDSWORK: to support simple mode changes like @@ -163,15 +164,15 @@ static void read_props(void) uint32_t type_set = 0; while ((t = buffer_read_line(&input)) && strcmp(t, "PROPS-END")) { uint32_t len; - const char *val; const char type = t[0]; int ch; if (!type || t[1] != ' ') die("invalid property line: %s\n", t); len = atoi(&t[2]); - val = buffer_read_string(&input, len); - if (!val || strlen(val) != len) + strbuf_reset(&val); + buffer_read_binary(&input, &val, len); + if (val.len < len) die_short_read(); /* Discard trailing newline. */ @@ -179,22 +180,17 @@ static void read_props(void) if (ch == EOF) die_short_read(); if (ch != '\n') - die("invalid dump: expected newline after %s", val); + die("invalid dump: expected newline after %s", val.buf); switch (type) { case 'K': + strbuf_swap(&key, &val); + continue; case 'D': - strbuf_reset(&key); - if (val) - strbuf_add(&key, val, len); - if (type == 'K') - continue; - assert(type == 'D'); - val = NULL; - len = 0; - /* fall through */ + handle_property(&val, NULL, 0, &type_set); + continue; case 'V': - handle_property(&key, val, len, &type_set); + handle_property(&key, val.buf, len, &type_set); strbuf_reset(&key); continue; default:
-- 1.7.4.1