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authorLibravatar Jeff King <peff@peff.net>2020-03-27 04:03:38 -0400
committerLibravatar Junio C Hamano <gitster@pobox.com>2020-03-27 12:18:48 -0700
commit4845b7724582a315eb4eb13d5058f85d21798e94 (patch)
tree8d27c4687e289d16d784aa1bf4c86be160ab532d
parenttest-lib-functions: make packetize() more efficient (diff)
downloadtgif-4845b7724582a315eb4eb13d5058f85d21798e94.tar.xz
upload-pack: handle unexpected delim packets
When processing the arguments list for a v2 ls-refs or fetch command, we loop like this: while (packet_reader_read(request) != PACKET_READ_FLUSH) { const char *arg = request->line; ...handle arg... } to read and handle packets until we see a flush. The hidden assumption here is that anything except PACKET_READ_FLUSH will give us valid packet data to read. But that's not true; PACKET_READ_DELIM or PACKET_READ_EOF will leave packet->line as NULL, and we'll segfault trying to look at it. Instead, we should follow the more careful model demonstrated on the client side (e.g., in process_capabilities_v2): keep looping as long as we get normal packets, and then make sure that we broke out of the loop due to a real flush. That fixes the segfault and correctly diagnoses any unexpected input from the client. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
-rw-r--r--ls-refs.c5
-rwxr-xr-xt/t5704-protocol-violations.sh33
-rw-r--r--upload-pack.c5
3 files changed, 41 insertions, 2 deletions
diff --git a/ls-refs.c b/ls-refs.c
index 818aef70a0..50d86866c6 100644
--- a/ls-refs.c
+++ b/ls-refs.c
@@ -93,7 +93,7 @@ int ls_refs(struct repository *r, struct argv_array *keys,
git_config(ls_refs_config, NULL);
- while (packet_reader_read(request) != PACKET_READ_FLUSH) {
+ while (packet_reader_read(request) == PACKET_READ_NORMAL) {
const char *arg = request->line;
const char *out;
@@ -105,6 +105,9 @@ int ls_refs(struct repository *r, struct argv_array *keys,
argv_array_push(&data.prefixes, out);
}
+ if (request->status != PACKET_READ_FLUSH)
+ die(_("expected flush after ls-refs arguments"));
+
head_ref_namespaced(send_ref, &data);
for_each_namespaced_ref(send_ref, &data);
packet_flush(1);
diff --git a/t/t5704-protocol-violations.sh b/t/t5704-protocol-violations.sh
new file mode 100755
index 0000000000..950cfb21fe
--- /dev/null
+++ b/t/t5704-protocol-violations.sh
@@ -0,0 +1,33 @@
+#!/bin/sh
+
+test_description='Test responses to violations of the network protocol. In most
+of these cases it will generally be acceptable for one side to break off
+communications if the other side says something unexpected. We are mostly
+making sure that we do not segfault or otherwise behave badly.'
+. ./test-lib.sh
+
+test_expect_success 'extra delim packet in v2 ls-refs args' '
+ {
+ packetize command=ls-refs &&
+ printf 0001 &&
+ # protocol expects 0000 flush here
+ printf 0001
+ } >input &&
+ test_must_fail env GIT_PROTOCOL=version=2 \
+ git upload-pack . <input 2>err &&
+ test_i18ngrep "expected flush after ls-refs arguments" err
+'
+
+test_expect_success 'extra delim packet in v2 fetch args' '
+ {
+ packetize command=fetch &&
+ printf 0001 &&
+ # protocol expects 0000 flush here
+ printf 0001
+ } >input &&
+ test_must_fail env GIT_PROTOCOL=version=2 \
+ git upload-pack . <input 2>err &&
+ test_i18ngrep "expected flush after fetch arguments" err
+'
+
+test_done
diff --git a/upload-pack.c b/upload-pack.c
index c53249cac1..902d0ad5e1 100644
--- a/upload-pack.c
+++ b/upload-pack.c
@@ -1252,7 +1252,7 @@ static void process_args(struct packet_reader *request,
struct upload_pack_data *data,
struct object_array *want_obj)
{
- while (packet_reader_read(request) != PACKET_READ_FLUSH) {
+ while (packet_reader_read(request) == PACKET_READ_NORMAL) {
const char *arg = request->line;
const char *p;
@@ -1321,6 +1321,9 @@ static void process_args(struct packet_reader *request,
/* ignore unknown lines maybe? */
die("unexpected line: '%s'", arg);
}
+
+ if (request->status != PACKET_READ_FLUSH)
+ die(_("expected flush after fetch arguments"));
}
static int process_haves(struct oid_array *haves, struct oid_array *common,