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// SPDX-License-Identifier: GPL-2.0
#include <errno.h>
#include <limits.h>
#include <linux/capability.h>
#include <stdio.h>
#include <sys/msg.h>
#include <sys/syscall.h>
#include <unistd.h>
#include "kselftest.h"
static int drop_cap_sys_resource(void)
{
struct __user_cap_header_struct hdr = {
.version = _LINUX_CAPABILITY_VERSION_3,
};
struct __user_cap_data_struct data[_LINUX_CAPABILITY_U32S_3];
unsigned int index = CAP_SYS_RESOURCE / 32;
__u32 mask = 1U << (CAP_SYS_RESOURCE % 32);
if (syscall(SYS_capget, &hdr, data))
return -1;
data[index].effective &= ~mask;
data[index].permitted &= ~mask;
return syscall(SYS_capset, &hdr, data);
}
int main(void)
{
struct msqid_ds ds;
int msqid;
int ret;
ksft_print_header();
ksft_set_plan(1);
#if ULONG_MAX <= UINT_MAX
ksft_exit_skip("requires unsigned long wider than unsigned int\n");
#endif
if (drop_cap_sys_resource()) {
if (errno == ENOSYS)
ksft_exit_skip("capabilities are unavailable\n");
ksft_exit_fail_perror("drop CAP_SYS_RESOURCE");
}
msqid = msgget(IPC_PRIVATE, 0600);
if (msqid == -1) {
if (errno == ENOSYS)
ksft_exit_skip("System V message queues are unavailable\n");
ksft_exit_fail_perror("msgget");
}
ret = msgctl(msqid, IPC_STAT, &ds);
if (ret == -1) {
ksft_perror("msgctl(IPC_STAT)");
goto out_fail;
}
/*
* Without CAP_SYS_RESOURCE, a value above UINT_MAX must be rejected
* rather than truncated to zero.
*/
ds.msg_qbytes = (unsigned long)UINT_MAX + 1;
errno = 0;
ret = msgctl(msqid, IPC_SET, &ds);
if (ret == -1 && errno == EPERM) {
ksft_test_result_pass("IPC_SET rejects oversized msg_qbytes\n");
msgctl(msqid, IPC_RMID, NULL);
ksft_exit_pass();
}
if (ret == -1)
ksft_perror("msgctl(IPC_SET)");
else
ksft_print_msg("msgctl(IPC_SET) unexpectedly succeeded\n");
out_fail:
msgctl(msqid, IPC_RMID, NULL);
ksft_test_result_fail("IPC_SET accepted oversized msg_qbytes\n");
ksft_exit_fail();
}
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