Since commit 5454df9c31 ("rename: check source file access early")
rename fails early for symlinks with non-existing target (regression),
because access() dereferences the link.
From access(2):
"access() checks whether the calling process can access the file pathname.
If pathname is a symbolic link, it is dereferenced."
Thus replace access() with faccessat() and lstat() as fallback,
(as in do_symlink()), that is equivalent for symlink and files.
From fsaccess(2) and stat(2):
"The faccessat() system call operates in exactly the same way as access(),
except for the differences described here.
[...]
If pathname is relative and dirfd is the special value AT_FDCWD, then pathname
is interpreted relative to the current working directory of the calling process
(like access()).
[...]
AT_SYMLINK_NOFOLLOW
If pathname is a symbolic link, do not dereference it:
instead return information about the link itself."
"lstat() is identical to stat(), except that if pathname is a symbolic link, then
it returns information about the link itself, not the file that it refers to."
Testing
-------
1) symlink with existing target
2) symlink with non-existing target
3) non-existing symlink
4) existing file
5) non-existing file
Before:
$ touch file-found
$ ln -s file-found symlink-1
$ ./rename sym symbolic- symlink-1 # XPASS.
$ echo $?
0
$ ln -s file-not-found symlink-2
$ ./rename sym symbolic- symlink-2 # FAIL! REGRESSION.
rename: symlink-2: not accessible: No such file or directory
$ echo $?
1
$ ./rename sym symbolic- symlink-3 # XFAIL.
rename: symlink-3: not accessible: No such file or directory
$ echo $?
1
$ touch file-found
$ ./rename found existing file-found # XPASS.
$ echo $?
0
$ ./rename found existing file-not-found # XFAIL.
rename: file-not-found: not accessible: No such file or directory
$ echo $?
1
After:
$ touch file-found
$ ln -s file-found symlink-1
$ ./rename sym symbolic- symlink-1 # XPASS.
$ echo $?
0
$ ln -s file-not-found symlink-2
$ ./rename sym symbolic- symlink-2 # PASS! REGRESSION FIXED.
$ echo $?
0
$ ./rename sym symbolic- symlink-3 # XFAIL.
rename: symlink-3: not accessible: No such file or directory
$ echo $?
1
$ touch file-found
$ ./rename found existing file-found # XPASS.
$ echo $?
0
$ ./rename found existing file-not-found # XFAIL.
rename: file-not-found: not accessible: No such file or directory
$ echo $?
1
And to test/simulate faccessat()'s EINVAL for AT_SYMLINK_NOFOLLOW
for Mac OS X, per commit 826538bf64 ("rename: skip faccessat()
failure if AT_SYMLINK_NOFOLLOW is not a valid flag"), forced 'if'
to evaluate to false so that lstat() is taken.
It still fails early; the error messages are slightly different
('not accessible' vs. 'stat of ... failed') but still tell same
'No such file or directory'; exit code is the same as well.
$ ./rename sym symbolic- symlink-3 # XFAIL. DIFF MSG/SAME RC.
rename: stat of symlink-3 failed: No such file or directory
$ echo $?
1
$ ./rename found existing file-not-found # XFAIL. DIFF MSG/SAME RC.
rename: stat of file-not-found failed: No such file or directory
$ echo $?
1
Tested on commit 2b41c409e ("Merge branch 'blkd-err' of ...")
Signed-off-by: Mauricio Faria de Oliveira <mfo@canonical.com>
Enabling libcrypsetup in libmount had several unintended side
effects.
First of all, it increases the Debian minimal image size by
~2.5% (5.6MB worth of new libraries).
Then, due to libcryptsetup linkage to OpenSSL and libjson-c,
it causes incompatibilities with external programs linking
against both libmount and a private, static, old version of
OpenSSL, or external programs linking against libjansson or
json-glib, which have one symbol in common with libjson-c.
If ./configure is ran with --with-crypsetup=dlopen,
instead of linking to libcrypsetup, use dlopen to resolve
the symbols at runtime only when the verity feature is
used, thus avoiding clashes and keeping images size down.
Fixes#1081
Signed-off-by: Luca Boccassi <luca.boccassi@microsoft.com>
* 'blkd-err' of https://github.com/evverx/util-linux:
tests: turn off detect_leaks on s390x, use more asan options
tests: skip "blkid/dm-err" when `mknod` doesn't work
ts_init_py meddles with LD_LIBRARY_PATH causing those tests to fail with
```
+Traceback (most recent call last):
+ File "/home/travis/build/karelzak/util-linux/libmount/python/test_mount_tab.py", line 8, in <module>
+ import pylibmount as mnt
+ImportError: /home/travis/build/karelzak/util-linux/.libs/libblkid.so.1: undefined symbol: __ubsan_handle_negate_overflow
}}}-diff
```
Backtraces like
```
misc-utils/cal.c:295:4: runtime error: signed integer overflow: 2147483647 + 5 cannot be represented in type 'int'
==1405==WARNING: invalid path to external symbolizer!
==1405==WARNING: Failed to use and restart external symbolizer!
#0 0x4c4c09 (/home/travis/build/karelzak/util-linux/cal+0x4c4c09)
#1 0x7f4363046b96 (/lib/x86_64-linux-gnu/libc.so.6+0x21b96)
#2 0x41bab9 (/home/travis/build/karelzak/util-linux/cal+0x41bab9)
SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior misc-utils/cal.c:295:4 in
```
aren't very helpful
It's follow-up to https://github.com/karelzak/util-linux/pull/1075
* 'bionic' of https://github.com/evverx/util-linux:
travis: make it easier to switch to the next clang/gcc
travis: switch to clang-10
travis: switch to gcc-10
travis: ignore memory leaks in checkusage
travis: install all the "official" build dependencies
travis: switch to Bionic
Evgeny Vereshchagin
Yuri Chornoivan
Karel Zak
Mauricio Faria de Oliveira
Luca Boccassi
Daan De Meyer