diff options
| -rw-r--r-- | fs/file.c | 44 | ||||
| -rw-r--r-- | fs/open.c | 4 | ||||
| -rw-r--r-- | include/uapi/linux/close_range.h | 3 | ||||
| -rw-r--r-- | tools/testing/selftests/core/close_range_test.c | 74 | ||||
| -rw-r--r-- | tools/testing/selftests/openat2/openat2_test.c | 8 |
5 files changed, 122 insertions, 11 deletions
diff --git a/fs/file.c b/fs/file.c index 4559b5fec3bd..e08e4daccac3 100644 --- a/fs/file.c +++ b/fs/file.c @@ -674,6 +674,35 @@ int __close_fd(struct files_struct *files, unsigned fd) } EXPORT_SYMBOL(__close_fd); /* for ksys_close() */ +static inline void __range_cloexec(struct files_struct *cur_fds, + unsigned int fd, unsigned int max_fd) +{ + struct fdtable *fdt; + + if (fd > max_fd) + return; + + spin_lock(&cur_fds->file_lock); + fdt = files_fdtable(cur_fds); + bitmap_set(fdt->close_on_exec, fd, max_fd - fd + 1); + spin_unlock(&cur_fds->file_lock); +} + +static inline void __range_close(struct files_struct *cur_fds, unsigned int fd, + unsigned int max_fd) +{ + while (fd <= max_fd) { + struct file *file; + + file = pick_file(cur_fds, fd++); + if (!file) + continue; + + filp_close(file, cur_fds); + cond_resched(); + } +} + /** * __close_range() - Close all file descriptors in a given range. * @@ -689,7 +718,7 @@ int __close_range(unsigned fd, unsigned max_fd, unsigned int flags) struct task_struct *me = current; struct files_struct *cur_fds = me->files, *fds = NULL; - if (flags & ~CLOSE_RANGE_UNSHARE) + if (flags & ~(CLOSE_RANGE_UNSHARE | CLOSE_RANGE_CLOEXEC)) return -EINVAL; if (fd > max_fd) @@ -727,16 +756,11 @@ int __close_range(unsigned fd, unsigned max_fd, unsigned int flags) } max_fd = min(max_fd, cur_max); - while (fd <= max_fd) { - struct file *file; - file = pick_file(cur_fds, fd++); - if (!file) - continue; - - filp_close(file, cur_fds); - cond_resched(); - } + if (flags & CLOSE_RANGE_CLOEXEC) + __range_cloexec(cur_fds, fd, max_fd); + else + __range_close(cur_fds, fd, max_fd); if (fds) { /* diff --git a/fs/open.c b/fs/open.c index 9af548fb841b..4d7537ae59df 100644 --- a/fs/open.c +++ b/fs/open.c @@ -1010,6 +1010,10 @@ inline int build_open_flags(const struct open_how *how, struct open_flags *op) if (how->resolve & ~VALID_RESOLVE_FLAGS) return -EINVAL; + /* Scoping flags are mutually exclusive. */ + if ((how->resolve & RESOLVE_BENEATH) && (how->resolve & RESOLVE_IN_ROOT)) + return -EINVAL; + /* Deal with the mode. */ if (WILL_CREATE(flags)) { if (how->mode & ~S_IALLUGO) diff --git a/include/uapi/linux/close_range.h b/include/uapi/linux/close_range.h index 6928a9fdee3c..2d804281554c 100644 --- a/include/uapi/linux/close_range.h +++ b/include/uapi/linux/close_range.h @@ -5,5 +5,8 @@ /* Unshare the file descriptor table before closing file descriptors. */ #define CLOSE_RANGE_UNSHARE (1U << 1) +/* Set the FD_CLOEXEC bit instead of closing the file descriptor. */ +#define CLOSE_RANGE_CLOEXEC (1U << 2) + #endif /* _UAPI_LINUX_CLOSE_RANGE_H */ diff --git a/tools/testing/selftests/core/close_range_test.c b/tools/testing/selftests/core/close_range_test.c index 575b391ddc78..87e16d65d9d7 100644 --- a/tools/testing/selftests/core/close_range_test.c +++ b/tools/testing/selftests/core/close_range_test.c @@ -11,6 +11,7 @@ #include <string.h> #include <syscall.h> #include <unistd.h> +#include <sys/resource.h> #include "../kselftest_harness.h" #include "../clone3/clone3_selftests.h" @@ -23,6 +24,10 @@ #define CLOSE_RANGE_UNSHARE (1U << 1) #endif +#ifndef CLOSE_RANGE_CLOEXEC +#define CLOSE_RANGE_CLOEXEC (1U << 2) +#endif + static inline int sys_close_range(unsigned int fd, unsigned int max_fd, unsigned int flags) { @@ -224,4 +229,73 @@ TEST(close_range_unshare_capped) EXPECT_EQ(0, WEXITSTATUS(status)); } +TEST(close_range_cloexec) +{ + int i, ret; + int open_fds[101]; + struct rlimit rlimit; + + for (i = 0; i < ARRAY_SIZE(open_fds); i++) { + int fd; + + fd = open("/dev/null", O_RDONLY); + ASSERT_GE(fd, 0) { + if (errno == ENOENT) + XFAIL(return, "Skipping test since /dev/null does not exist"); + } + + open_fds[i] = fd; + } + + ret = sys_close_range(1000, 1000, CLOSE_RANGE_CLOEXEC); + if (ret < 0) { + if (errno == ENOSYS) + XFAIL(return, "close_range() syscall not supported"); + if (errno == EINVAL) + XFAIL(return, "close_range() doesn't support CLOSE_RANGE_CLOEXEC"); + } + + /* Ensure the FD_CLOEXEC bit is set also with a resource limit in place. */ + ASSERT_EQ(0, getrlimit(RLIMIT_NOFILE, &rlimit)); + rlimit.rlim_cur = 25; + ASSERT_EQ(0, setrlimit(RLIMIT_NOFILE, &rlimit)); + + /* Set close-on-exec for two ranges: [0-50] and [75-100]. */ + ret = sys_close_range(open_fds[0], open_fds[50], CLOSE_RANGE_CLOEXEC); + ASSERT_EQ(0, ret); + ret = sys_close_range(open_fds[75], open_fds[100], CLOSE_RANGE_CLOEXEC); + ASSERT_EQ(0, ret); + + for (i = 0; i <= 50; i++) { + int flags = fcntl(open_fds[i], F_GETFD); + + EXPECT_GT(flags, -1); + EXPECT_EQ(flags & FD_CLOEXEC, FD_CLOEXEC); + } + + for (i = 51; i <= 74; i++) { + int flags = fcntl(open_fds[i], F_GETFD); + + EXPECT_GT(flags, -1); + EXPECT_EQ(flags & FD_CLOEXEC, 0); + } + + for (i = 75; i <= 100; i++) { + int flags = fcntl(open_fds[i], F_GETFD); + + EXPECT_GT(flags, -1); + EXPECT_EQ(flags & FD_CLOEXEC, FD_CLOEXEC); + } + + /* Test a common pattern. */ + ret = sys_close_range(3, UINT_MAX, CLOSE_RANGE_CLOEXEC); + for (i = 0; i <= 100; i++) { + int flags = fcntl(open_fds[i], F_GETFD); + + EXPECT_GT(flags, -1); + EXPECT_EQ(flags & FD_CLOEXEC, FD_CLOEXEC); + } +} + + TEST_HARNESS_MAIN diff --git a/tools/testing/selftests/openat2/openat2_test.c b/tools/testing/selftests/openat2/openat2_test.c index b386367c606b..381d874cce99 100644 --- a/tools/testing/selftests/openat2/openat2_test.c +++ b/tools/testing/selftests/openat2/openat2_test.c @@ -155,7 +155,7 @@ struct flag_test { int err; }; -#define NUM_OPENAT2_FLAG_TESTS 23 +#define NUM_OPENAT2_FLAG_TESTS 24 void test_openat2_flags(void) { @@ -210,6 +210,12 @@ void test_openat2_flags(void) .how.flags = O_TMPFILE | O_RDWR, .how.mode = 0x0000A00000000000ULL, .err = -EINVAL }, + /* ->resolve flags must not conflict. */ + { .name = "incompatible resolve flags (BENEATH | IN_ROOT)", + .how.flags = O_RDONLY, + .how.resolve = RESOLVE_BENEATH | RESOLVE_IN_ROOT, + .err = -EINVAL }, + /* ->resolve must only contain RESOLVE_* flags. */ { .name = "invalid how.resolve and O_RDONLY", .how.flags = O_RDONLY, |