diff options
| author | Eric Blake <eblake@redhat.com> | 2020-04-20 12:53:08 -0500 |
|---|---|---|
| committer | Eric Blake <eblake@redhat.com> | 2020-05-04 14:54:35 -0500 |
| commit | 474a6e64f2c3c17718b853b9d70e054ee8d26f37 (patch) | |
| tree | 2cf2b2a0a8e525a7a82a7d2e8c329ef8f0c67672 /util/systemd.c | |
| parent | 5375af3cd7b8adcc10c18d8083b7be63976c9645 (diff) | |
tools: Fix use of fcntl(F_SETFD) during socket activation
Blindly setting FD_CLOEXEC without a read-modify-write will
inadvertently clear any other intentionally-set bits, such as a
proposed new bit for designating a fd that must behave in 32-bit mode.
However, we cannot use our wrapper qemu_set_cloexec(), because that
wrapper intentionally abort()s on failure, whereas the probe here
intentionally tolerates failure to deal with incorrect socket
activation gracefully. Instead, fix the code to do the proper
read-modify-write.
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200420175309.75894-3-eblake@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Diffstat (limited to 'util/systemd.c')
| -rw-r--r-- | util/systemd.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/util/systemd.c b/util/systemd.c index 1dd0367d9a..5bcac9b401 100644 --- a/util/systemd.c +++ b/util/systemd.c @@ -23,6 +23,7 @@ unsigned int check_socket_activation(void) unsigned long nr_fds; unsigned int i; int fd; + int f; int err; s = getenv("LISTEN_PID"); @@ -54,7 +55,8 @@ unsigned int check_socket_activation(void) /* So the file descriptors don't leak into child processes. */ for (i = 0; i < nr_fds; ++i) { fd = FIRST_SOCKET_ACTIVATION_FD + i; - if (fcntl(fd, F_SETFD, FD_CLOEXEC) == -1) { + f = fcntl(fd, F_GETFD); + if (f == -1 || fcntl(fd, F_SETFD, f | FD_CLOEXEC) == -1) { /* If we cannot set FD_CLOEXEC then it probably means the file * descriptor is invalid, so socket activation has gone wrong * and we should exit. |