Paul Eggert wrote:
> If you compile and run the attached
> program on a file that you don't own (e.g., './a.out /'), does it
> incorrectly issue "Permission denied" instead of "Operation not
> permitted" diagnostics?
In this case, the diagnostic is "Operation not permitted" (from EPERM):
$ ./a.out /
lchown: Operation not permitted
fchownat: Operation not permitted
chown: Operation not permitted
fchown: Operation not permitted
$ strace ./a.out /
...
lchown("/", 0, 0) = -1 EPERM (Operation not permitted)
dup(2) = 3
fcntl(3, F_GETFL) = 0x2 (flags O_RDWR)
getrandom("\x30\x26\x33\x40\x27\x47\x25\x78", 8, GRND_NONBLOCK) = 8
brk(NULL) = 0x55f0af430000
brk(0x55f0af451000) = 0x55f0af451000
newfstatat(3, "", {st_mode=S_IFCHR|0600, st_rdev=makedev(0x88, 0x9), ...},
AT_EMPTY_PATH) = 0
write(3, "lchown: Operation not permitted\n", 32lchown: Operation not permitted
) = 32
close(3) = 0
fchownat(AT_FDCWD, "/", 0, 0, AT_SYMLINK_NOFOLLOW) = -1 EPERM (Operation not
permitted)
dup(2) = 3
fcntl(3, F_GETFL) = 0x2 (flags O_RDWR)
newfstatat(3, "", {st_mode=S_IFCHR|0600, st_rdev=makedev(0x88, 0x9), ...},
AT_EMPTY_PATH) = 0
write(3, "fchownat: Operation not permitte"..., 34fchownat: Operation not
permitted
) = 34
close(3) = 0
chown("/", 0, 0) = -1 EPERM (Operation not permitted)
dup(2) = 3
fcntl(3, F_GETFL) = 0x2 (flags O_RDWR)
newfstatat(3, "", {st_mode=S_IFCHR|0600, st_rdev=makedev(0x88, 0x9), ...},
AT_EMPTY_PATH) = 0
write(3, "chown: Operation not permitted\n", 31chown: Operation not permitted
) = 31
close(3) = 0
openat(AT_FDCWD, "/", O_RDONLY|O_NOFOLLOW) = 3
fchown(3, 0, 0) = -1 EPERM (Operation not permitted)
dup(2) = 4
fcntl(4, F_GETFL) = 0x2 (flags O_RDWR)
newfstatat(4, "", {st_mode=S_IFCHR|0600, st_rdev=makedev(0x88, 0x9), ...},
AT_EMPTY_PATH) = 0
write(4, "fchown: Operation not permitted\n", 32fchown: Operation not permitted
) = 32
close(4) = 0
exit_group(1) = ?
+++ exited with 1 +++
Bruno
