If receive a request like:
git-upload-pack /foo.git\0host=localhost
we mark the offset of the NUL byte as "len", and then log
the bytes after the NUL with a "%.*s" placeholder, using
"pktlen - len" as the length, and "line + len + 1" as the
start of the string.
This is off-by-one, since the start of the string skips past
the separating NUL byte, but the adjusted length includes
it. Fortunately this doesn't actually read past the end of
the buffer, since "%.*s" will stop when it hits a NUL. And
regardless of what is in the buffer, packet_read() will
always add an extra NUL terminator for safety.
As an aside, the git.git client sends an extra NUL after a
"host" field, too, so we'd generally hit that one first, not
the one added by packet_read(). You can see this in the test
output which reports 15 bytes, even though the string has
only 14 bytes of visible data. But the point is that even a
client sending unusual data could not get us to read past
the end of the buffer, so this is purely a cosmetic fix.
Reported-by: Michael Haggerty <mhag...@alum.mit.edu>
Signed-off-by: Jeff King <p...@peff.net>
---
This code actually goes away in the next patch, but I thought it was
worth dealing with individually, since it is a memory error (albeit a
harmless one).
daemon.c | 4 ++--
t/t5570-git-daemon.sh | 11 +++++++++++
2 files changed, 13 insertions(+), 2 deletions(-)
diff --git a/daemon.c b/daemon.c
index e37e343d0a..d78afc8e96 100644
--- a/daemon.c
+++ b/daemon.c
@@ -759,8 +759,8 @@ static int execute(void)
len = strlen(line);
if (pktlen != len)
loginfo("Extended attributes (%d bytes) exist <%.*s>",
- (int) pktlen - len,
- (int) pktlen - len, line + len + 1);
+ (int) pktlen - len - 1,
+ (int) pktlen - len - 1, line + len + 1);
if (len && line[len-1] == '\n') {
line[--len] = 0;
pktlen--;
diff --git a/t/t5570-git-daemon.sh b/t/t5570-git-daemon.sh
index f92ebc5cd5..359af3994a 100755
--- a/t/t5570-git-daemon.sh
+++ b/t/t5570-git-daemon.sh
@@ -183,5 +183,16 @@ test_expect_success 'hostname cannot break out of
directory' '
git ls-remote "$GIT_DAEMON_URL/escape.git"
'
+test_expect_success 'daemon log records hostnames' '
+ cat >expect <<-\EOF &&
+ Extended attributes (15 bytes) exist <host=localhost>
+ EOF
+ >daemon.log &&
+ GIT_OVERRIDE_VIRTUAL_HOST=localhost \
+ git ls-remote "$GIT_DAEMON_URL/interp.git" &&
+ grep -i extended.attribute daemon.log | cut -d" " -f2- >actual &&
+ test_cmp expect actual
+'
+
stop_git_daemon
test_done
--
2.16.1.273.gfdaa03aa74
