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From: "Jeff Hostetler via GitGitGadget" <gitgitgadget@gmail.com>
To: git@vger.kernel.org
Cc: "Jeff Hostetler" <git@jeffhostetler.com>,
	"Jeff King" <peff@peff.net>,
	"SZEDER Gábor" <szeder.dev@gmail.com>,
	"Johannes Schindelin" <Johannes.Schindelin@gmx.de>,
	"Jeff Hostetler" <jeffhost@microsoft.com>,
	"Jeff Hostetler" <jeffhost@microsoft.com>
Subject: [PATCH v4 09/12] unix-socket: disallow chdir() when creating unix domain sockets
Date: Wed, 17 Feb 2021 21:48:45 +0000	[thread overview]
Message-ID: <1bfa36409d0706d5e22703f80bf95dfa1a313a83.1613598529.git.gitgitgadget@gmail.com> (raw)
In-Reply-To: <pull.766.v4.git.1613598529.gitgitgadget@gmail.com>

From: Jeff Hostetler <jeffhost@microsoft.com>

Calls to `chdir()` are dangerous in a multi-threaded context.  If
`unix_stream_listen()` or `unix_stream_connect()` is given a socket
pathname that is too long to fit in a `sockaddr_un` structure, it will
`chdir()` to the parent directory of the requested socket pathname,
create the socket using a relative pathname, and then `chdir()` back.
This is not thread-safe.

Teach `unix_sockaddr_init()` to not allow calls to `chdir()` when this
flag is set.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 builtin/credential-cache.c |  2 +-
 unix-socket.c              | 17 ++++++++++++-----
 unix-socket.h              |  4 +++-
 3 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/builtin/credential-cache.c b/builtin/credential-cache.c
index 9b3f70990597..76a6ba37223f 100644
--- a/builtin/credential-cache.c
+++ b/builtin/credential-cache.c
@@ -14,7 +14,7 @@
 static int send_request(const char *socket, const struct strbuf *out)
 {
 	int got_data = 0;
-	int fd = unix_stream_connect(socket);
+	int fd = unix_stream_connect(socket, 0);
 
 	if (fd < 0)
 		return -1;
diff --git a/unix-socket.c b/unix-socket.c
index 5ac7dafe9828..1eaa8cf759c0 100644
--- a/unix-socket.c
+++ b/unix-socket.c
@@ -28,16 +28,23 @@ static void unix_sockaddr_cleanup(struct unix_sockaddr_context *ctx)
 }
 
 static int unix_sockaddr_init(struct sockaddr_un *sa, const char *path,
-			      struct unix_sockaddr_context *ctx)
+			      struct unix_sockaddr_context *ctx,
+			      int disallow_chdir)
 {
 	int size = strlen(path) + 1;
 
 	ctx->orig_dir = NULL;
 	if (size > sizeof(sa->sun_path)) {
-		const char *slash = find_last_dir_sep(path);
+		const char *slash;
 		const char *dir;
 		struct strbuf cwd = STRBUF_INIT;
 
+		if (disallow_chdir) {
+			errno = ENAMETOOLONG;
+			return -1;
+		}
+
+		slash = find_last_dir_sep(path);
 		if (!slash) {
 			errno = ENAMETOOLONG;
 			return -1;
@@ -63,13 +70,13 @@ static int unix_sockaddr_init(struct sockaddr_un *sa, const char *path,
 	return 0;
 }
 
-int unix_stream_connect(const char *path)
+int unix_stream_connect(const char *path, int disallow_chdir)
 {
 	int fd = -1, saved_errno;
 	struct sockaddr_un sa;
 	struct unix_sockaddr_context ctx;
 
-	if (unix_sockaddr_init(&sa, path, &ctx) < 0)
+	if (unix_sockaddr_init(&sa, path, &ctx, disallow_chdir) < 0)
 		return -1;
 	fd = socket(AF_UNIX, SOCK_STREAM, 0);
 	if (fd < 0)
@@ -99,7 +106,7 @@ int unix_stream_listen(const char *path,
 
 	unlink(path);
 
-	if (unix_sockaddr_init(&sa, path, &ctx) < 0)
+	if (unix_sockaddr_init(&sa, path, &ctx, opts->disallow_chdir) < 0)
 		return -1;
 	fd = socket(AF_UNIX, SOCK_STREAM, 0);
 	if (fd < 0)
diff --git a/unix-socket.h b/unix-socket.h
index 06a5a05b03fe..2c0b2e79d7b3 100644
--- a/unix-socket.h
+++ b/unix-socket.h
@@ -3,6 +3,7 @@
 
 struct unix_stream_listen_opts {
 	int listen_backlog_size;
+	unsigned int disallow_chdir:1;
 };
 
 #define DEFAULT_UNIX_STREAM_LISTEN_BACKLOG (5)
@@ -10,9 +11,10 @@ struct unix_stream_listen_opts {
 #define UNIX_STREAM_LISTEN_OPTS_INIT \
 { \
 	.listen_backlog_size = DEFAULT_UNIX_STREAM_LISTEN_BACKLOG, \
+	.disallow_chdir = 0, \
 }
 
-int unix_stream_connect(const char *path);
+int unix_stream_connect(const char *path, int disallow_chdir);
 int unix_stream_listen(const char *path,
 		       const struct unix_stream_listen_opts *opts);
 
-- 
gitgitgadget


  parent reply	other threads:[~2021-02-17 21:51 UTC|newest]

Thread overview: 178+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-12 15:31 [PATCH 00/10] [RFC] Simple IPC Mechanism Jeff Hostetler via GitGitGadget
2021-01-12 15:31 ` [PATCH 01/10] pkt-line: use stack rather than static buffer in packet_write_gently() Jeff Hostetler via GitGitGadget
2021-01-13 13:29   ` Jeff King
2021-01-25 19:34     ` Jeff Hostetler
2021-01-12 15:31 ` [PATCH 02/10] pkt-line: (optionally) libify the packet readers Johannes Schindelin via GitGitGadget
2021-01-12 15:31 ` [PATCH 03/10] pkt-line: optionally skip the flush packet in write_packetized_from_buf() Johannes Schindelin via GitGitGadget
2021-01-12 15:31 ` [PATCH 04/10] pkt-line: accept additional options in read_packetized_to_strbuf() Johannes Schindelin via GitGitGadget
2021-01-12 15:31 ` [PATCH 05/10] simple-ipc: design documentation for new IPC mechanism Jeff Hostetler via GitGitGadget
2021-01-12 16:40   ` Ævar Arnfjörð Bjarmason
2021-01-12 15:31 ` [PATCH 06/10] simple-ipc: add win32 implementation Jeff Hostetler via GitGitGadget
2021-01-12 15:31 ` [PATCH 07/10] unix-socket: create gentle version of unix_stream_listen() Jeff Hostetler via GitGitGadget
2021-01-13 14:06   ` Jeff King
2021-01-14  1:19     ` Chris Torek
2021-01-12 15:31 ` [PATCH 08/10] unix-socket: add no-chdir option to unix_stream_listen_gently() Jeff Hostetler via GitGitGadget
2021-01-12 15:31 ` [PATCH 09/10] simple-ipc: add t/helper/test-simple-ipc and t0052 Jeff Hostetler via GitGitGadget
2021-01-12 15:31 ` [PATCH 10/10] simple-ipc: add Unix domain socket implementation Jeff Hostetler via GitGitGadget
2021-01-12 16:50 ` [PATCH 00/10] [RFC] Simple IPC Mechanism Ævar Arnfjörð Bjarmason
2021-01-12 18:25   ` Jeff Hostetler
2021-01-12 20:01 ` Junio C Hamano
2021-01-12 23:25   ` Jeff Hostetler
2021-01-13  0:13     ` Junio C Hamano
2021-01-13  0:32       ` Jeff Hostetler
2021-01-13 13:46     ` Jeff King
2021-01-13 15:48       ` Ævar Arnfjörð Bjarmason
2021-02-01 19:45 ` [PATCH v2 00/14] " Jeff Hostetler via GitGitGadget
2021-02-01 19:45   ` [PATCH v2 01/14] ci/install-depends: attempt to fix "brew cask" stuff Junio C Hamano via GitGitGadget
2021-02-01 19:45   ` [PATCH v2 02/14] pkt-line: promote static buffer in packet_write_gently() to callers Jeff Hostetler via GitGitGadget
2021-02-02  9:41     ` Jeff King
2021-02-02 20:33       ` Jeff Hostetler
2021-02-02 22:54       ` Johannes Schindelin
2021-02-03  4:52         ` Jeff King
2021-02-01 19:45   ` [PATCH v2 03/14] pkt-line: add write_packetized_from_buf2() that takes scratch buffer Jeff Hostetler via GitGitGadget
2021-02-02  9:44     ` Jeff King
2021-02-01 19:45   ` [PATCH v2 04/14] pkt-line: optionally skip the flush packet in write_packetized_from_buf() Johannes Schindelin via GitGitGadget
2021-02-02  9:48     ` Jeff King
2021-02-02 22:56       ` Johannes Schindelin
2021-02-05 18:30       ` Jeff Hostetler
2021-02-01 19:45   ` [PATCH v2 05/14] pkt-line: (optionally) libify the packet readers Johannes Schindelin via GitGitGadget
2021-02-01 19:45   ` [PATCH v2 06/14] pkt-line: accept additional options in read_packetized_to_strbuf() Johannes Schindelin via GitGitGadget
2021-02-11  1:52     ` Taylor Blau
2021-02-01 19:45   ` [PATCH v2 07/14] simple-ipc: design documentation for new IPC mechanism Jeff Hostetler via GitGitGadget
2021-02-01 19:45   ` [PATCH v2 08/14] simple-ipc: add win32 implementation Jeff Hostetler via GitGitGadget
2021-02-01 19:45   ` [PATCH v2 09/14] simple-ipc: add t/helper/test-simple-ipc and t0052 Jeff Hostetler via GitGitGadget
2021-02-02 21:35     ` SZEDER Gábor
2021-02-03  4:36       ` Jeff King
2021-02-09 15:45       ` Jeff Hostetler
2021-02-05 19:38     ` SZEDER Gábor
2021-02-01 19:45   ` [PATCH v2 10/14] unix-socket: elimiate static unix_stream_socket() helper function Jeff Hostetler via GitGitGadget
2021-02-02  9:54     ` Jeff King
2021-02-02  9:58     ` Jeff King
2021-02-01 19:45   ` [PATCH v2 11/14] unix-socket: add options to unix_stream_listen() Jeff Hostetler via GitGitGadget
2021-02-02 10:14     ` Jeff King
2021-02-05 23:28       ` Jeff Hostetler
2021-02-09 16:32         ` Jeff King
2021-02-09 17:39           ` Jeff Hostetler
2021-02-10 15:55             ` Jeff King
2021-02-10 21:31               ` Jeff Hostetler
2021-02-01 19:45   ` [PATCH v2 12/14] unix-socket: add no-chdir option " Jeff Hostetler via GitGitGadget
2021-02-02 10:26     ` Jeff King
2021-02-01 19:45   ` [PATCH v2 13/14] unix-socket: do not call die in unix_stream_connect() Jeff Hostetler via GitGitGadget
2021-02-01 19:45   ` [PATCH v2 14/14] simple-ipc: add Unix domain socket implementation Jeff Hostetler via GitGitGadget
2021-02-01 22:20   ` [PATCH v2 00/14] Simple IPC Mechanism Junio C Hamano
2021-02-01 23:26     ` Jeff Hostetler
2021-02-02 23:07       ` Johannes Schindelin
2021-02-04 19:08         ` Junio C Hamano
2021-02-05 13:19           ` candidate branches for `maint`, was " Johannes Schindelin
2021-02-05 19:55             ` Junio C Hamano
2021-02-13  0:09   ` [PATCH v3 00/12] " Jeff Hostetler via GitGitGadget
2021-02-13  0:09     ` [PATCH v3 01/12] pkt-line: eliminate the need for static buffer in packet_write_gently() Jeff Hostetler via GitGitGadget
2021-02-13  0:09     ` [PATCH v3 02/12] pkt-line: do not issue flush packets in write_packetized_*() Johannes Schindelin via GitGitGadget
2021-02-13  0:09     ` [PATCH v3 03/12] pkt-line: (optionally) libify the packet readers Johannes Schindelin via GitGitGadget
2021-02-13  0:09     ` [PATCH v3 04/12] pkt-line: add options argument to read_packetized_to_strbuf() Johannes Schindelin via GitGitGadget
2021-02-13  0:09     ` [PATCH v3 05/12] simple-ipc: design documentation for new IPC mechanism Jeff Hostetler via GitGitGadget
2021-02-13  0:09     ` [PATCH v3 06/12] simple-ipc: add win32 implementation Jeff Hostetler via GitGitGadget
2021-02-13  0:09     ` [PATCH v3 07/12] unix-socket: elimiate static unix_stream_socket() helper function Jeff Hostetler via GitGitGadget
2021-02-13  0:09     ` [PATCH v3 08/12] unix-socket: add backlog size option to unix_stream_listen() Jeff Hostetler via GitGitGadget
2021-02-13  0:09     ` [PATCH v3 09/12] unix-socket: disallow chdir() when creating unix domain sockets Jeff Hostetler via GitGitGadget
2021-02-13  0:09     ` [PATCH v3 10/12] unix-socket: create `unix_stream_server__listen_with_lock()` Jeff Hostetler via GitGitGadget
2021-02-13  0:09     ` [PATCH v3 11/12] simple-ipc: add Unix domain socket implementation Jeff Hostetler via GitGitGadget
2021-02-13  0:09     ` [PATCH v3 12/12] t0052: add simple-ipc tests and t/helper/test-simple-ipc tool Jeff Hostetler via GitGitGadget
2021-02-13  9:30       ` SZEDER Gábor
2021-02-16 15:53         ` Jeff Hostetler
2021-02-17 21:48     ` [PATCH v4 00/12] Simple IPC Mechanism Jeff Hostetler via GitGitGadget
2021-02-17 21:48       ` [PATCH v4 01/12] pkt-line: eliminate the need for static buffer in packet_write_gently() Jeff Hostetler via GitGitGadget
2021-02-26  7:21         ` Jeff King
2021-02-26 19:52           ` Jeff Hostetler
2021-02-26 20:43             ` Jeff King
2021-03-03 19:38             ` Junio C Hamano
2021-03-04 13:29               ` Jeff Hostetler
2021-03-04 20:26                 ` Junio C Hamano
2021-02-17 21:48       ` [PATCH v4 02/12] pkt-line: do not issue flush packets in write_packetized_*() Johannes Schindelin via GitGitGadget
2021-02-17 21:48       ` [PATCH v4 03/12] pkt-line: (optionally) libify the packet readers Johannes Schindelin via GitGitGadget
2021-03-03 19:53         ` Junio C Hamano
2021-03-04 14:17           ` Jeff Hostetler
2021-03-04 14:40             ` Jeff King
2021-03-04 20:28               ` Junio C Hamano
2021-02-17 21:48       ` [PATCH v4 04/12] pkt-line: add options argument to read_packetized_to_strbuf() Johannes Schindelin via GitGitGadget
2021-02-17 21:48       ` [PATCH v4 05/12] simple-ipc: design documentation for new IPC mechanism Jeff Hostetler via GitGitGadget
2021-03-03 20:19         ` Junio C Hamano
2021-02-17 21:48       ` [PATCH v4 06/12] simple-ipc: add win32 implementation Jeff Hostetler via GitGitGadget
2021-02-17 21:48       ` [PATCH v4 07/12] unix-socket: elimiate static unix_stream_socket() helper function Jeff Hostetler via GitGitGadget
2021-02-26  7:25         ` Jeff King
2021-03-03 20:41         ` Junio C Hamano
2021-02-17 21:48       ` [PATCH v4 08/12] unix-socket: add backlog size option to unix_stream_listen() Jeff Hostetler via GitGitGadget
2021-02-26  7:30         ` Jeff King
2021-03-03 20:54           ` Junio C Hamano
2021-02-17 21:48       ` Jeff Hostetler via GitGitGadget [this message]
2021-03-03 22:53         ` [PATCH v4 09/12] unix-socket: disallow chdir() when creating unix domain sockets Junio C Hamano
2021-03-04 14:56           ` Jeff King
2021-03-04 20:34             ` Junio C Hamano
2021-03-04 23:34               ` Junio C Hamano
2021-03-05  9:02                 ` Jeff King
2021-03-05  9:25                   ` Jeff King
2021-03-05 11:59                     ` Chris Torek
2021-03-05 17:33                       ` Jeff Hostetler
2021-03-05 17:53                         ` Junio C Hamano
2021-03-05 21:30               ` Jeff Hostetler
2021-03-05 21:52                 ` Junio C Hamano
2021-02-17 21:48       ` [PATCH v4 10/12] unix-socket: create `unix_stream_server__listen_with_lock()` Jeff Hostetler via GitGitGadget
2021-02-26  7:56         ` Jeff King
2021-03-02 23:50           ` Jeff Hostetler
2021-03-04 15:13             ` Jeff King
2021-02-17 21:48       ` [PATCH v4 11/12] simple-ipc: add Unix domain socket implementation Jeff Hostetler via GitGitGadget
2021-02-17 21:48       ` [PATCH v4 12/12] t0052: add simple-ipc tests and t/helper/test-simple-ipc tool Jeff Hostetler via GitGitGadget
2021-03-02  9:44         ` Jeff King
2021-03-03 15:25           ` Jeff Hostetler
2021-02-25 19:39       ` [PATCH v4 00/12] Simple IPC Mechanism Junio C Hamano
2021-02-26  7:59         ` Jeff King
2021-02-26 20:18           ` Jeff Hostetler
2021-02-26 20:50             ` Jeff King
2021-03-03 19:29               ` Junio C Hamano
2021-03-09 15:02       ` [PATCH v5 " Jeff Hostetler via GitGitGadget
2021-03-09 15:02         ` [PATCH v5 01/12] pkt-line: eliminate the need for static buffer in packet_write_gently() Jeff Hostetler via GitGitGadget
2021-03-09 23:48           ` Junio C Hamano
2021-03-11 19:29             ` Jeff King
2021-03-11 20:32               ` Junio C Hamano
2021-03-11 20:53                 ` Jeff King
2021-03-09 15:02         ` [PATCH v5 02/12] pkt-line: do not issue flush packets in write_packetized_*() Johannes Schindelin via GitGitGadget
2021-03-09 15:02         ` [PATCH v5 03/12] pkt-line: add PACKET_READ_GENTLE_ON_READ_ERROR option Johannes Schindelin via GitGitGadget
2021-03-09 15:02         ` [PATCH v5 04/12] pkt-line: add options argument to read_packetized_to_strbuf() Johannes Schindelin via GitGitGadget
2021-03-09 15:02         ` [PATCH v5 05/12] simple-ipc: design documentation for new IPC mechanism Jeff Hostetler via GitGitGadget
2021-03-09 15:02         ` [PATCH v5 06/12] simple-ipc: add win32 implementation Jeff Hostetler via GitGitGadget
2021-03-09 15:02         ` [PATCH v5 07/12] unix-socket: eliminate static unix_stream_socket() helper function Jeff Hostetler via GitGitGadget
2021-03-09 15:02         ` [PATCH v5 08/12] unix-socket: add backlog size option to unix_stream_listen() Jeff Hostetler via GitGitGadget
2021-03-09 15:02         ` [PATCH v5 09/12] unix-socket: disallow chdir() when creating unix domain sockets Jeff Hostetler via GitGitGadget
2021-03-09 15:02         ` [PATCH v5 10/12] unix-stream-server: create unix domain socket under lock Jeff Hostetler via GitGitGadget
2021-03-10  0:18           ` Junio C Hamano
2021-03-09 15:02         ` [PATCH v5 11/12] simple-ipc: add Unix domain socket implementation Jeff Hostetler via GitGitGadget
2021-03-10  0:08           ` Junio C Hamano
2021-03-15 19:56             ` Jeff Hostetler
2021-03-09 15:02         ` [PATCH v5 12/12] t0052: add simple-ipc tests and t/helper/test-simple-ipc tool Jeff Hostetler via GitGitGadget
2021-03-09 23:28         ` [PATCH v5 00/12] Simple IPC Mechanism Junio C Hamano
2021-03-15 21:08         ` [PATCH v6 " Jeff Hostetler via GitGitGadget
2021-03-15 21:08           ` [PATCH v6 01/12] pkt-line: eliminate the need for static buffer in packet_write_gently() Jeff Hostetler via GitGitGadget
2021-03-15 21:08           ` [PATCH v6 02/12] pkt-line: do not issue flush packets in write_packetized_*() Johannes Schindelin via GitGitGadget
2021-03-15 21:08           ` [PATCH v6 03/12] pkt-line: add PACKET_READ_GENTLE_ON_READ_ERROR option Johannes Schindelin via GitGitGadget
2021-03-15 21:08           ` [PATCH v6 04/12] pkt-line: add options argument to read_packetized_to_strbuf() Johannes Schindelin via GitGitGadget
2021-03-15 21:08           ` [PATCH v6 05/12] simple-ipc: design documentation for new IPC mechanism Jeff Hostetler via GitGitGadget
2021-03-15 21:08           ` [PATCH v6 06/12] simple-ipc: add win32 implementation Jeff Hostetler via GitGitGadget
2021-03-15 21:08           ` [PATCH v6 07/12] unix-socket: eliminate static unix_stream_socket() helper function Jeff Hostetler via GitGitGadget
2021-03-15 21:08           ` [PATCH v6 08/12] unix-socket: add backlog size option to unix_stream_listen() Jeff Hostetler via GitGitGadget
2021-03-15 21:08           ` [PATCH v6 09/12] unix-socket: disallow chdir() when creating unix domain sockets Jeff Hostetler via GitGitGadget
2021-03-15 21:08           ` [PATCH v6 10/12] unix-stream-server: create unix domain socket under lock Jeff Hostetler via GitGitGadget
2021-03-15 21:08           ` [PATCH v6 11/12] simple-ipc: add Unix domain socket implementation Jeff Hostetler via GitGitGadget
2021-03-15 21:08           ` [PATCH v6 12/12] t0052: add simple-ipc tests and t/helper/test-simple-ipc tool Jeff Hostetler via GitGitGadget
2021-03-22 10:29           ` [PATCH v7 00/12] Simple IPC Mechanism Jeff Hostetler via GitGitGadget
2021-03-22 10:29             ` [PATCH v7 01/12] pkt-line: eliminate the need for static buffer in packet_write_gently() Jeff Hostetler via GitGitGadget
2021-03-22 10:29             ` [PATCH v7 02/12] pkt-line: do not issue flush packets in write_packetized_*() Johannes Schindelin via GitGitGadget
2021-03-22 10:29             ` [PATCH v7 03/12] pkt-line: add PACKET_READ_GENTLE_ON_READ_ERROR option Johannes Schindelin via GitGitGadget
2021-03-22 10:29             ` [PATCH v7 04/12] pkt-line: add options argument to read_packetized_to_strbuf() Johannes Schindelin via GitGitGadget
2021-03-22 10:29             ` [PATCH v7 05/12] simple-ipc: design documentation for new IPC mechanism Jeff Hostetler via GitGitGadget
2021-03-22 10:29             ` [PATCH v7 06/12] simple-ipc: add win32 implementation Jeff Hostetler via GitGitGadget
2021-03-22 10:29             ` [PATCH v7 07/12] unix-socket: eliminate static unix_stream_socket() helper function Jeff Hostetler via GitGitGadget
2021-03-22 10:29             ` [PATCH v7 08/12] unix-socket: add backlog size option to unix_stream_listen() Jeff Hostetler via GitGitGadget
2021-03-22 10:29             ` [PATCH v7 09/12] unix-socket: disallow chdir() when creating unix domain sockets Jeff Hostetler via GitGitGadget
2021-03-22 10:29             ` [PATCH v7 10/12] unix-stream-server: create unix domain socket under lock Jeff Hostetler via GitGitGadget
2021-03-22 10:29             ` [PATCH v7 11/12] simple-ipc: add Unix domain socket implementation Jeff Hostetler via GitGitGadget
2021-03-22 10:29             ` [PATCH v7 12/12] t0052: add simple-ipc tests and t/helper/test-simple-ipc tool Jeff Hostetler via GitGitGadget

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