Since this kernel is presumably built on Redhat's 5.14 kernel, has it been verified whether this fails the same way on current RHEL9? On Fri, Jan 24, 2025 at 5:05 PM Reiterer, Horst <horst.reiterer@xxxxxxxxxxxx> wrote: > > Hi, > > after updating from AlmaLinux 9.4 to 9.5 (https://repo.almalinux.org/vault/9.4/BaseOS/Source/Packages/kernel-5.14.0-427.40.1.el9_4.src.rpm vs. https://repo.almalinux.org/vault/9.5/BaseOS/Source/Packages/kernel-5.14.0-503.15.1.el9_5.src.rpm), chmod gets ignored by the CIFS filesystem when executed against a Windows file server unless chmod happens in another process. > > Mount options as reported by mount: > > rw,relatime,context=system_u:object_r:tmp_t:s0,vers=3.1.1,cache=strict,username=<username> > uid=0,noforceuid,gid=0,noforcegid,addr=<addr>,file_mode=0755,dir_mode=0755,soft > nounix,serverino,mapposix,reparse=nfs,rsize=4194304,wsize=4194304,bsize=1048576 > retrans=1,echo_interval=60,actimeo=1,closetimeo=1 > > Reproduction (see source below): > > ./test <path/to/mountpoint>/<non-existent-filename> all > Unexpected mode 100555 > > strace: > > openat(AT_FDCWD, "/mnt/test", O_WRONLY|O_CREAT|O_TRUNC, 0666) = 3 > close(3) = 0 > chmod("/mnt/test", 0400) = 0 > openat(AT_FDCWD, "/mnt/test", O_RDONLY) = 3 > close(3) = 0 > newfstatat(AT_FDCWD, "/mnt/test", {st_dev=makedev(0, 0x2b), st_ino=1407374884039565, st_mode=S_IFREG|0555, st_nlink=1, st_uid=0, st_gid=0, st_blksize=1048576, st_blocks=0, st_size=0, st_atime=17 > 37759300 /* 2025-01-24T23:55:00.242552200+0100 */, st_atime_nsec=242552200, st_mtime=1737759300 /* 2025-01-24T23:55:00.242552200+0100 */, st_mtime_nsec=242552200, st_ctime=1737759300 /* 2025-01- > 24T23:55:00.243552200+0100 */, st_ctime_nsec=243552200}, 0) = 0 > chmod("/mnt/test", 0600) = 0 > newfstatat(AT_FDCWD, "/mnt/test", {st_dev=makedev(0, 0x2b), st_ino=1407374884039565, st_mode=S_IFREG|0555, st_nlink=1, st_uid=0, st_gid=0, st_blksize=1048576, st_blocks=0, st_size=0, st_atime=17 > 37759300 /* 2025-01-24T23:55:00.242552200+0100 */, st_atime_nsec=242552200, st_mtime=1737759300 /* 2025-01-24T23:55:00.242552200+0100 */, st_mtime_nsec=242552200, st_ctime=1737759300 /* 2025-01- > 24T23:55:00.245552200+0100 */, st_ctime_nsec=245552200}, 0) = 0 > write(2, "Unexpected mode 100555\n", 23Unexpected mode 100555 > ) = 23 > exit_group(1) = ? > +++ exited with 1 +++ > > Workaround (executing the test in two processes): > > ./test <path/to/mountpoint>/<non-existent-filename> first > ./test <path/to/mountpoint>/<non-existent-filename> last > > strace: > > openat(AT_FDCWD, "/mnt/test", O_WRONLY|O_CREAT|O_TRUNC, 0666) = 3 > close(3) = 0 > chmod("/mnt/test", 0400) = 0 > openat(AT_FDCWD, "/mnt/test", O_RDONLY) = 3 > close(3) = 0 > exit_group(0) = ? > +++ exited with 0 +++ > > newfstatat(AT_FDCWD, "/mnt/test", {st_dev=makedev(0, 0x2b), st_ino=1407374884039566, st_mode=S_IFREG|0555, st_nlink=1, st_uid=0, st_gid=0, st_blksize=1048576, st_blocks=0, st_size=0, st_atime=17 > 37759424 /* 2025-01-24T23:57:04.152930200+0100 */, st_atime_nsec=152930200, st_mtime=1737759424 /* 2025-01-24T23:57:04.152930200+0100 */, st_mtime_nsec=152930200, st_ctime=1737759424 /* 2025-01- > 24T23:57:04.152930200+0100 */, st_ctime_nsec=152930200}, 0) = 0 > chmod("/mnt/test", 0600) = 0 > newfstatat(AT_FDCWD, "/mnt/test", {st_dev=makedev(0, 0x2b), st_ino=1407374884039566, st_mode=S_IFREG|0755, st_nlink=1, st_uid=0, st_gid=0, st_blksize=1048576, st_blocks=0, st_size=0, st_atime=17 > 37759424 /* 2025-01-24T23:57:04.152930200+0100 */, st_atime_nsec=152930200, st_mtime=1737759424 /* 2025-01-24T23:57:04.152930200+0100 */, st_mtime_nsec=152930200, st_ctime=1737759449 /* 2025-01- > 24T23:57:29.621213500+0100 */, st_ctime_nsec=621213500}, 0) = 0 > openat(AT_FDCWD, "/mnt/test", O_WRONLY|O_CREAT|O_TRUNC, 0666) = 3 > close(3) = 0 > exit_group(0) = ? > +++ exited with 0 +++ > > Please let me know if your can reproduce the issue using the sample. > > Cheers, > > Horst Reiterer > > test.c: > #include <fcntl.h> > #include <stdio.h> > #include <stdlib.h> > #include <string.h> > #include <sys/stat.h> > #include <sys/types.h> > #include <unistd.h> > > int main(int argc, char *argv[]) > { > if (argc != 3) { > fprintf(stderr, "test <path> <all|first|last>\n"); > return 2; > } > char *path = argv[1]; > char *mode = argv[2]; > int fd; > if (strcmp(mode, "all") == 0 || strcmp(mode, "first") == 0) { > if ((fd = open(path, O_WRONLY|O_CREAT|O_TRUNC, 0666)) == -1) { > perror("open"); > return 1; > } > close(fd); > if (chmod(path, 0400) == -1) { > perror("chmod"); > return 1; > } > if ((fd = open(path, O_RDONLY)) == -1) { > perror("open"); > return 1; > } > close(fd); > } > if (strcmp(mode, "all") == 0 || strcmp(mode, "last") == 0) { > struct stat statbuf; > if (stat(path, &statbuf) == -1) { > perror("stat"); > return 1; > } > mode_t modebefore = statbuf.st_mode; > if (chmod(path, 0600) == -1) { > perror("chmod"); > return 1; > } > if (stat(path, &statbuf) == -1) { > perror("stat"); > return 1; > } > if (statbuf.st_mode == modebefore) { > fprintf(stderr, "Unexpected mode %o\n", statbuf.st_mode); > return 1; > } > if ((fd = open(path, O_WRONLY|O_CREAT|O_TRUNC, 0666)) == -1) { > perror("open"); > return 1; > } > close(fd); > } > return 0; > } > -- Thanks, Steve
