diff options
| author |  Jeff Hostetler <jeffhost@microsoft.com> | 2021-03-15 21:08:26 +0000 |
|---|---|---|
| committer |  Junio C Hamano <gitster@pobox.com> | 2021-03-15 14:32:51 -0700 |
| commit | 77e522caaeebe8c6378dcf7045b19cbd22c8b2fb (patch) | |
| tree | a935ff8bd5ce0802dfda6fbd530e99f07446f491 | |
| parent | unix-socket: add backlog size option to unix_stream_listen() (diff) | |
| download | tgif-77e522caaeebe8c6378dcf7045b19cbd22c8b2fb.tar.xz | |
unix-socket: disallow chdir() when creating unix domain sockets
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>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
| -rw-r--r-- | builtin/credential-cache.c | 2 | ||||
| -rw-r--r-- | unix-socket.c | 17 | ||||
| -rw-r--r-- | unix-socket.h | 3 |
3 files changed, 15 insertions, 7 deletions
diff --git a/builtin/credential-cache.c b/builtin/credential-cache.c index 9b3f709905..76a6ba3722 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 012becd93d..e0be1badb5 100644 --- a/unix-socket.c +++ b/unix-socket.c @@ -30,16 +30,23 @@ 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; @@ -65,13 +72,13 @@ 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) @@ -101,7 +108,7 @@ 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 ec2fb3ea72..8542cdd799 100644 --- a/unix-socket.h +++ b/unix-socket.h @@ -3,11 +3,12 @@ struct unix_stream_listen_opts { int listen_backlog_size; + unsigned int disallow_chdir:1; }; #define UNIX_STREAM_LISTEN_OPTS_INIT { 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); |