diff options
| author | Ed Maste <emaste@FreeBSD.org> | 2026-05-26 13:24:36 +0000 |
|---|---|---|
| committer | Ed Maste <emaste@FreeBSD.org> | 2026-05-26 19:18:56 +0000 |
| commit | b9d16b7fd2fa6bc4b3e8364804cbdc1b76ebe8a5 (patch) | |
| tree | 7d5a87bf19db2a78fdd60d8e72481ffce6347761 | |
| parent | c564074c9aaa8a3f9273de3cb802edcb3e2e2a40 (diff) | |
sigqueue: In capability mode, only allow signalling self
This is copied from the check in kern_kill.
Reviewed by: markj, oshogbo
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D57244
| -rw-r--r-- | sys/kern/kern_sig.c | 10 | ||||
| -rw-r--r-- | tests/sys/capsicum/capmode.cc | 12 |
2 files changed, 19 insertions, 3 deletions
diff --git a/sys/kern/kern_sig.c b/sys/kern/kern_sig.c index 9be7c82ee98b..e48997ed966a 100644 --- a/sys/kern/kern_sig.c +++ b/sys/kern/kern_sig.c @@ -2038,6 +2038,16 @@ kern_sigqueue(struct thread *td, pid_t pid, int signumf, union sigval *value) if (pid <= 0) return (EINVAL); + /* + * A process in capability mode can send signals only to itself. + */ + if (pid != td->td_proc->p_pid) { + if (CAP_TRACING(td)) + ktrcapfail(CAPFAIL_SIGNAL, &signum); + if (IN_CAPABILITY_MODE(td)) + return (ECAPMODE); + } + if ((signumf & __SIGQUEUE_TID) == 0) { if ((p = pfind_any(pid)) == NULL) return (ESRCH); diff --git a/tests/sys/capsicum/capmode.cc b/tests/sys/capsicum/capmode.cc index c6eef19b350f..fdc572f11b5b 100644 --- a/tests/sys/capsicum/capmode.cc +++ b/tests/sys/capsicum/capmode.cc @@ -703,8 +703,8 @@ FORK_TEST(Capmode, NewThread) { close(thread_pipe[1]); } -static volatile sig_atomic_t had_signal = 0; -static void handle_signal(int) { had_signal = 1; } +static volatile sig_atomic_t signal_cnt = 0; +static void handle_signal(int) { signal_cnt++; } FORK_TEST(Capmode, SelfKill) { pid_t me = getpid(); @@ -722,7 +722,13 @@ FORK_TEST(Capmode, SelfKill) { // Can only kill(2) to own pid. EXPECT_CAPMODE(kill(child, SIGUSR1)); EXPECT_OK(kill(me, SIGUSR1)); - EXPECT_EQ(1, had_signal); + EXPECT_EQ(1, signal_cnt); + + union sigval sv; + sv.sival_int = 0x1234; + EXPECT_CAPMODE(sigqueue(child, SIGUSR1, sv)); + EXPECT_OK(sigqueue(me, SIGUSR1, sv)); + EXPECT_EQ(2, signal_cnt); signal(SIGUSR1, original); } |