Subject: bug#48106: bug: touch utility does not handle file create error properly

From: Roland <[email-masked]>
Date: Thu, 29 Apr 2021 20:23:47 +0200

hello,

touch utility telling weird error on file creation on a immutable/ro dir.

apparently, it does not catch/report the first error (EPERM) but only
the second one (ENOENT), when trying to set the time on the non-existing
file.

regards
roland kletzing
sysadmin

root@s900:/tmp# mkdir /tmp/test
root@s900:/tmp# chown 0400 /tmp/test/
root@s900:/tmp# chattr +i /tmp/test
root@s900:/tmp# touch /tmp/test/testfile
touch: setting times of '/tmp/test/testfile': No such file or directory

root@s900:/tmp# strace touch /tmp/test/testfile 2>&1 |grep -i test
execve("/usr/bin/touch", ["touch", "/tmp/test/testfile"], 0x7ffe690abb88
/* 19 vars */) = 0
openat(AT_FDCWD, "/tmp/test/testfile",
O_WRONLY|O_CREAT|O_NOCTTY|O_NONBLOCK, 0666) = -1 EPERM (Operation not
permitted)
utimensat(AT_FDCWD, "/tmp/test/testfile", NULL, 0) = -1 ENOENT (No such
file or directory)
write(2, "setting times of '/tmp/test/test"..., 37setting times of
'/tmp/test/testfile') = 37

# touch  --version
touch (GNU coreutils) 8.30

(on debian 10.9)