diff --git a/arch/alpha/kernel/syscalls/syscall.tbl b/arch/alpha/kernel/syscalls/syscall.tbl index 1f13995d00d7..ad37569d0507 100644 --- a/arch/alpha/kernel/syscalls/syscall.tbl +++ b/arch/alpha/kernel/syscalls/syscall.tbl @@ -491,3 +491,4 @@ 559 common futex_waitv sys_futex_waitv 560 common set_mempolicy_home_node sys_ni_syscall 561 common cachestat sys_cachestat +562 common fchmodat2 sys_fchmodat2 diff --git a/arch/arm/tools/syscall.tbl b/arch/arm/tools/syscall.tbl index 8ebed8a13874..c572d6c3dee0 100644 --- a/arch/arm/tools/syscall.tbl +++ b/arch/arm/tools/syscall.tbl @@ -465,3 +465,4 @@ 449 common futex_waitv sys_futex_waitv 450 common set_mempolicy_home_node sys_set_mempolicy_home_node 451 common cachestat sys_cachestat +452 common fchmodat2 sys_fchmodat2 diff --git a/arch/arm64/include/asm/unistd.h b/arch/arm64/include/asm/unistd.h index 64a514f90131..bd77253b62e0 100644 --- a/arch/arm64/include/asm/unistd.h +++ b/arch/arm64/include/asm/unistd.h @@ -39,7 +39,7 @@ #define __ARM_NR_compat_set_tls (__ARM_NR_COMPAT_BASE + 5) #define __ARM_NR_COMPAT_END (__ARM_NR_COMPAT_BASE + 0x800) -#define __NR_compat_syscalls 452 +#define __NR_compat_syscalls 453 #endif #define __ARCH_WANT_SYS_CLONE diff --git a/arch/arm64/include/asm/unistd32.h b/arch/arm64/include/asm/unistd32.h index d952a28463e0..78b68311ec81 100644 --- a/arch/arm64/include/asm/unistd32.h +++ b/arch/arm64/include/asm/unistd32.h @@ -909,6 +909,8 @@ __SYSCALL(__NR_futex_waitv, sys_futex_waitv) __SYSCALL(__NR_set_mempolicy_home_node, sys_set_mempolicy_home_node) #define __NR_cachestat 451 __SYSCALL(__NR_cachestat, sys_cachestat) +#define __NR_fchmodat2 452 +__SYSCALL(__NR_fchmodat2, sys_fchmodat2) /* * Please add new compat syscalls above this comment and update diff --git a/arch/ia64/kernel/syscalls/syscall.tbl b/arch/ia64/kernel/syscalls/syscall.tbl index f8c74ffeeefb..83d8609aec03 100644 --- a/arch/ia64/kernel/syscalls/syscall.tbl +++ b/arch/ia64/kernel/syscalls/syscall.tbl @@ -372,3 +372,4 @@ 449 common futex_waitv sys_futex_waitv 450 common set_mempolicy_home_node sys_set_mempolicy_home_node 451 common cachestat sys_cachestat +452 common fchmodat2 sys_fchmodat2 diff --git a/arch/m68k/kernel/syscalls/syscall.tbl b/arch/m68k/kernel/syscalls/syscall.tbl index 4f504783371f..259ceb125367 100644 --- a/arch/m68k/kernel/syscalls/syscall.tbl +++ b/arch/m68k/kernel/syscalls/syscall.tbl @@ -451,3 +451,4 @@ 449 common futex_waitv sys_futex_waitv 450 common set_mempolicy_home_node sys_set_mempolicy_home_node 451 common cachestat sys_cachestat +452 common fchmodat2 sys_fchmodat2 diff --git a/arch/microblaze/kernel/syscalls/syscall.tbl b/arch/microblaze/kernel/syscalls/syscall.tbl index 858d22bf275c..a3798c2637fd 100644 --- a/arch/microblaze/kernel/syscalls/syscall.tbl +++ b/arch/microblaze/kernel/syscalls/syscall.tbl @@ -457,3 +457,4 @@ 449 common futex_waitv sys_futex_waitv 450 common set_mempolicy_home_node sys_set_mempolicy_home_node 451 common cachestat sys_cachestat +452 common fchmodat2 sys_fchmodat2 diff --git a/arch/mips/kernel/syscalls/syscall_n32.tbl b/arch/mips/kernel/syscalls/syscall_n32.tbl index 1976317d4e8b..152034b8e0a0 100644 --- a/arch/mips/kernel/syscalls/syscall_n32.tbl +++ b/arch/mips/kernel/syscalls/syscall_n32.tbl @@ -390,3 +390,4 @@ 449 n32 futex_waitv sys_futex_waitv 450 n32 set_mempolicy_home_node sys_set_mempolicy_home_node 451 n32 cachestat sys_cachestat +452 n32 fchmodat2 sys_fchmodat2 diff --git a/arch/mips/kernel/syscalls/syscall_n64.tbl b/arch/mips/kernel/syscalls/syscall_n64.tbl index cfda2511badf..cb5e757f6621 100644 --- a/arch/mips/kernel/syscalls/syscall_n64.tbl +++ b/arch/mips/kernel/syscalls/syscall_n64.tbl @@ -366,3 +366,4 @@ 449 n64 futex_waitv sys_futex_waitv 450 common set_mempolicy_home_node sys_set_mempolicy_home_node 451 n64 cachestat sys_cachestat +452 n64 fchmodat2 sys_fchmodat2 diff --git a/arch/mips/kernel/syscalls/syscall_o32.tbl b/arch/mips/kernel/syscalls/syscall_o32.tbl index 7692234c3768..1a646813afdc 100644 --- a/arch/mips/kernel/syscalls/syscall_o32.tbl +++ b/arch/mips/kernel/syscalls/syscall_o32.tbl @@ -439,3 +439,4 @@ 449 o32 futex_waitv sys_futex_waitv 450 o32 set_mempolicy_home_node sys_set_mempolicy_home_node 451 o32 cachestat sys_cachestat +452 o32 fchmodat2 sys_fchmodat2 diff --git a/arch/parisc/kernel/syscalls/syscall.tbl b/arch/parisc/kernel/syscalls/syscall.tbl index a0a9145b6dd4..e97c175b56f9 100644 --- a/arch/parisc/kernel/syscalls/syscall.tbl +++ b/arch/parisc/kernel/syscalls/syscall.tbl @@ -450,3 +450,4 @@ 449 common futex_waitv sys_futex_waitv 450 common set_mempolicy_home_node sys_set_mempolicy_home_node 451 common cachestat sys_cachestat +452 common fchmodat2 sys_fchmodat2 diff --git a/arch/powerpc/kernel/syscalls/syscall.tbl b/arch/powerpc/kernel/syscalls/syscall.tbl index 8c0b08b7a80e..20e50586e8a2 100644 --- a/arch/powerpc/kernel/syscalls/syscall.tbl +++ b/arch/powerpc/kernel/syscalls/syscall.tbl @@ -538,3 +538,4 @@ 449 common futex_waitv sys_futex_waitv 450 nospu set_mempolicy_home_node sys_set_mempolicy_home_node 451 common cachestat sys_cachestat +452 common fchmodat2 sys_fchmodat2 diff --git a/arch/s390/kernel/syscalls/syscall.tbl b/arch/s390/kernel/syscalls/syscall.tbl index a6935af2235c..0122cc156952 100644 --- a/arch/s390/kernel/syscalls/syscall.tbl +++ b/arch/s390/kernel/syscalls/syscall.tbl @@ -454,3 +454,4 @@ 449 common futex_waitv sys_futex_waitv sys_futex_waitv 450 common set_mempolicy_home_node sys_set_mempolicy_home_node sys_set_mempolicy_home_node 451 common cachestat sys_cachestat sys_cachestat +452 common fchmodat2 sys_fchmodat2 sys_fchmodat2 diff --git a/arch/sh/kernel/syscalls/syscall.tbl b/arch/sh/kernel/syscalls/syscall.tbl index 97377e8c5025..e90d585c4d3e 100644 --- a/arch/sh/kernel/syscalls/syscall.tbl +++ b/arch/sh/kernel/syscalls/syscall.tbl @@ -454,3 +454,4 @@ 449 common futex_waitv sys_futex_waitv 450 common set_mempolicy_home_node sys_set_mempolicy_home_node 451 common cachestat sys_cachestat +452 common fchmodat2 sys_fchmodat2 diff --git a/arch/sparc/kernel/syscalls/syscall.tbl b/arch/sparc/kernel/syscalls/syscall.tbl index faa835f3c54a..4ed06c71c43f 100644 --- a/arch/sparc/kernel/syscalls/syscall.tbl +++ b/arch/sparc/kernel/syscalls/syscall.tbl @@ -497,3 +497,4 @@ 449 common futex_waitv sys_futex_waitv 450 common set_mempolicy_home_node sys_set_mempolicy_home_node 451 common cachestat sys_cachestat +452 common fchmodat2 sys_fchmodat2 diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl index bc0a3c941b35..2d0b1bd866ea 100644 --- a/arch/x86/entry/syscalls/syscall_32.tbl +++ b/arch/x86/entry/syscalls/syscall_32.tbl @@ -456,3 +456,4 @@ 449 i386 futex_waitv sys_futex_waitv 450 i386 set_mempolicy_home_node sys_set_mempolicy_home_node 451 i386 cachestat sys_cachestat +452 i386 fchmodat2 sys_fchmodat2 diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl index 227538b0ce80..814768249eae 100644 --- a/arch/x86/entry/syscalls/syscall_64.tbl +++ b/arch/x86/entry/syscalls/syscall_64.tbl @@ -373,6 +373,7 @@ 449 common futex_waitv sys_futex_waitv 450 common set_mempolicy_home_node sys_set_mempolicy_home_node 451 common cachestat sys_cachestat +452 common fchmodat2 sys_fchmodat2 # # Due to a historical design error, certain syscalls are numbered differently diff --git a/arch/xtensa/kernel/syscalls/syscall.tbl b/arch/xtensa/kernel/syscalls/syscall.tbl index 2b69c3c035b6..fc1a4f3c81d9 100644 --- a/arch/xtensa/kernel/syscalls/syscall.tbl +++ b/arch/xtensa/kernel/syscalls/syscall.tbl @@ -422,3 +422,4 @@ 449 common futex_waitv sys_futex_waitv 450 common set_mempolicy_home_node sys_set_mempolicy_home_node 451 common cachestat sys_cachestat +452 common fchmodat2 sys_fchmodat2 diff --git a/fs/open.c b/fs/open.c index 023a20322f11..98f6601fbac6 100644 --- a/fs/open.c +++ b/fs/open.c @@ -671,11 +671,20 @@ SYSCALL_DEFINE2(fchmod, unsigned int, fd, umode_t, mode) return err; } -static int do_fchmodat(int dfd, const char __user *filename, umode_t mode) +static int do_fchmodat(int dfd, const char __user *filename, umode_t mode, + unsigned int flags) { struct path path; int error; - unsigned int lookup_flags = LOOKUP_FOLLOW; + unsigned int lookup_flags; + + if (unlikely(flags & ~(AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH))) + return -EINVAL; + + lookup_flags = (flags & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW; + if (flags & AT_EMPTY_PATH) + lookup_flags |= LOOKUP_EMPTY; + retry: error = user_path_at(dfd, filename, lookup_flags, &path); if (!error) { @@ -689,15 +698,21 @@ retry: return error; } +SYSCALL_DEFINE4(fchmodat2, int, dfd, const char __user *, filename, + umode_t, mode, unsigned int, flags) +{ + return do_fchmodat(dfd, filename, mode, flags); +} + SYSCALL_DEFINE3(fchmodat, int, dfd, const char __user *, filename, umode_t, mode) { - return do_fchmodat(dfd, filename, mode); + return do_fchmodat(dfd, filename, mode, 0); } SYSCALL_DEFINE2(chmod, const char __user *, filename, umode_t, mode) { - return do_fchmodat(AT_FDCWD, filename, mode); + return do_fchmodat(AT_FDCWD, filename, mode, 0); } /* diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index 03e3d0121d5e..5690aef7b3a8 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -438,8 +438,10 @@ asmlinkage long sys_chdir(const char __user *filename); asmlinkage long sys_fchdir(unsigned int fd); asmlinkage long sys_chroot(const char __user *filename); asmlinkage long sys_fchmod(unsigned int fd, umode_t mode); -asmlinkage long sys_fchmodat(int dfd, const char __user * filename, +asmlinkage long sys_fchmodat(int dfd, const char __user *filename, umode_t mode); +asmlinkage long sys_fchmodat2(int dfd, const char __user *filename, + umode_t mode, unsigned int flags); asmlinkage long sys_fchownat(int dfd, const char __user *filename, uid_t user, gid_t group, int flag); asmlinkage long sys_fchown(unsigned int fd, uid_t user, gid_t group); diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h index fd6c1cb585db..abe087c53b4b 100644 --- a/include/uapi/asm-generic/unistd.h +++ b/include/uapi/asm-generic/unistd.h @@ -820,8 +820,11 @@ __SYSCALL(__NR_set_mempolicy_home_node, sys_set_mempolicy_home_node) #define __NR_cachestat 451 __SYSCALL(__NR_cachestat, sys_cachestat) +#define __NR_fchmodat2 452 +__SYSCALL(__NR_fchmodat2, sys_fchmodat2) + #undef __NR_syscalls -#define __NR_syscalls 452 +#define __NR_syscalls 453 /* * 32 bit systems traditionally used different diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile index 666b56f22a41..8dca8acdb671 100644 --- a/tools/testing/selftests/Makefile +++ b/tools/testing/selftests/Makefile @@ -18,6 +18,7 @@ TARGETS += drivers/net/bonding TARGETS += drivers/net/team TARGETS += efivarfs TARGETS += exec +TARGETS += fchmodat2 TARGETS += filesystems TARGETS += filesystems/binderfs TARGETS += filesystems/epoll diff --git a/tools/testing/selftests/fchmodat2/.gitignore b/tools/testing/selftests/fchmodat2/.gitignore new file mode 100644 index 000000000000..82a4846cbc4b --- /dev/null +++ b/tools/testing/selftests/fchmodat2/.gitignore @@ -0,0 +1,2 @@ +# SPDX-License-Identifier: GPL-2.0-only +/*_test diff --git a/tools/testing/selftests/fchmodat2/Makefile b/tools/testing/selftests/fchmodat2/Makefile new file mode 100644 index 000000000000..20839f8e43f2 --- /dev/null +++ b/tools/testing/selftests/fchmodat2/Makefile @@ -0,0 +1,6 @@ +# SPDX-License-Identifier: GPL-2.0-or-later + +CFLAGS += -Wall -O2 -g -fsanitize=address -fsanitize=undefined $(KHDR_INCLUDES) +TEST_GEN_PROGS := fchmodat2_test + +include ../lib.mk diff --git a/tools/testing/selftests/fchmodat2/fchmodat2_test.c b/tools/testing/selftests/fchmodat2/fchmodat2_test.c new file mode 100644 index 000000000000..e0319417124d --- /dev/null +++ b/tools/testing/selftests/fchmodat2/fchmodat2_test.c @@ -0,0 +1,142 @@ +// SPDX-License-Identifier: GPL-2.0-or-later + +#define _GNU_SOURCE +#include +#include +#include +#include +#include + +#include "../kselftest.h" + +int sys_fchmodat2(int dfd, const char *filename, mode_t mode, int flags) +{ + int ret = syscall(__NR_fchmodat2, dfd, filename, mode, flags); + + return ret >= 0 ? ret : -errno; +} + +int setup_testdir(void) +{ + int dfd, ret; + char dirname[] = "/tmp/ksft-fchmodat2.XXXXXX"; + + /* Make the top-level directory. */ + if (!mkdtemp(dirname)) + ksft_exit_fail_msg("%s: failed to create tmpdir\n", __func__); + + dfd = open(dirname, O_PATH | O_DIRECTORY); + if (dfd < 0) + ksft_exit_fail_msg("%s: failed to open tmpdir\n", __func__); + + ret = openat(dfd, "regfile", O_CREAT | O_WRONLY | O_TRUNC, 0644); + if (ret < 0) + ksft_exit_fail_msg("%s: failed to create file in tmpdir\n", + __func__); + close(ret); + + ret = symlinkat("regfile", dfd, "symlink"); + if (ret < 0) + ksft_exit_fail_msg("%s: failed to create symlink in tmpdir\n", + __func__); + + return dfd; +} + +int expect_mode(int dfd, const char *filename, mode_t expect_mode) +{ + struct stat st; + int ret = fstatat(dfd, filename, &st, AT_SYMLINK_NOFOLLOW); + + if (ret) + ksft_exit_fail_msg("%s: %s: fstatat failed\n", + __func__, filename); + + return (st.st_mode == expect_mode); +} + +void test_regfile(void) +{ + int dfd, ret; + + dfd = setup_testdir(); + + ret = sys_fchmodat2(dfd, "regfile", 0640, 0); + + if (ret < 0) + ksft_exit_fail_msg("%s: fchmodat2(noflag) failed\n", __func__); + + if (!expect_mode(dfd, "regfile", 0100640)) + ksft_exit_fail_msg("%s: wrong file mode bits after fchmodat2\n", + __func__); + + ret = sys_fchmodat2(dfd, "regfile", 0600, AT_SYMLINK_NOFOLLOW); + + if (ret < 0) + ksft_exit_fail_msg("%s: fchmodat2(AT_SYMLINK_NOFOLLOW) failed\n", + __func__); + + if (!expect_mode(dfd, "regfile", 0100600)) + ksft_exit_fail_msg("%s: wrong file mode bits after fchmodat2 with nofollow\n", + __func__); + + ksft_test_result_pass("fchmodat2(regfile)\n"); +} + +void test_symlink(void) +{ + int dfd, ret; + + dfd = setup_testdir(); + + ret = sys_fchmodat2(dfd, "symlink", 0640, 0); + + if (ret < 0) + ksft_exit_fail_msg("%s: fchmodat2(noflag) failed\n", __func__); + + if (!expect_mode(dfd, "regfile", 0100640)) + ksft_exit_fail_msg("%s: wrong file mode bits after fchmodat2\n", + __func__); + + if (!expect_mode(dfd, "symlink", 0120777)) + ksft_exit_fail_msg("%s: wrong symlink mode bits after fchmodat2\n", + __func__); + + ret = sys_fchmodat2(dfd, "symlink", 0600, AT_SYMLINK_NOFOLLOW); + + /* + * On certain filesystems (xfs or btrfs), chmod operation fails. So we + * first check the symlink target but if the operation fails we mark the + * test as skipped. + * + * https://sourceware.org/legacy-ml/libc-alpha/2020-02/msg00467.html + */ + if (ret == 0 && !expect_mode(dfd, "symlink", 0120600)) + ksft_exit_fail_msg("%s: wrong symlink mode bits after fchmodat2 with nofollow\n", + __func__); + + if (!expect_mode(dfd, "regfile", 0100640)) + ksft_exit_fail_msg("%s: wrong file mode bits after fchmodat2 with nofollow\n", + __func__); + + if (ret != 0) + ksft_test_result_skip("fchmodat2(symlink)\n"); + else + ksft_test_result_pass("fchmodat2(symlink)\n"); +} + +#define NUM_TESTS 2 + +int main(int argc, char **argv) +{ + ksft_print_header(); + ksft_set_plan(NUM_TESTS); + + test_regfile(); + test_symlink(); + + if (ksft_get_fail_cnt() + ksft_get_error_cnt() > 0) + ksft_exit_fail(); + else + ksft_exit_pass(); +}