Historically, we've allowed read() of a directory and some filesystems will
accommodate (e.g. ufs/ffs, msdosfs). From the history department staffed by
Warner: <<EOF
pdp-7 unix seemed to allow reading directories, but they were weird, special
things there so I'm unsure (my pdp-7 assembler sucks).
1st Edition's sources are lost, mostly. The kernel allows it. The
reconstructed sources from 2nd or 3rd edition read it though.
V6 to V7 changed the filesystem format, and should have been a warning, but
reading directories weren't materially changed.
4.1b BSD introduced readdir because of UFS. UFS broke all directory reading
programs in 1983. ls, du, find, etc all had to be rewritten. readdir() and
friends were introduced here.
SysVr3 picked up readdir() in 1987 for the AT&T fork of Unix. SysVr4 updated
all the directory reading programs in 1988 because different filesystem
types were introduced.
In the 90s, these interfaces became completely ubiquitous as PDP-11s running
V7 faded from view and all the folks that initially started on V7 upgraded
to SysV. Linux never supported this (though I've not done the software
archeology to check) because it has always had a pathological diversity of
filesystems.
EOF
Disallowing read(2) on a directory has the side-effect of masking
application bugs from relying on other implementation's behavior
(e.g. Linux) of rejecting these with EISDIR across the board, but allowing
it has been a vector for at least one stack disclosure bug in the past[0].
By POSIX, this is implementation-defined whether read() handles directories
or not. Popular implementations have chosen to reject them, and this seems
sensible: the data you're reading from a directory is not structured in some
unified way across filesystem implementations like with readdir(2), so it is
impossible for applications to portably rely on this.
With this patch, we will reject most read(2) of a dirfd with EISDIR. Users
that know what they're doing can conscientiously set
bsd.security.allow_read_dir=1 to allow read(2) of directories, as it has
proven useful for debugging or recovery. A future commit will further limit
the sysctl to allow only the system root to read(2) directories, to make it
at least relatively safe to leave on for longer periods of time.
While we're adding logic pertaining to directory vnodes to vn_io_fault, an
additional assertion has also been added to ensure that we're not reaching
vn_io_fault with any write request on a directory vnode. Such request would
be a logical error in the kernel, and must be debugged rather than allowing
it to potentially silently error out.
Commented out shell aliases have been placed in root's chsrc/shrc to promote
awareness that grep may become noisy after this change, depending on your
usage.
A tentative MFC plan has been put together to try and make it as trivial as
possible to identify issues and collect reports; note that this will be
strongly re-evaluated. Tentatively, I will MFC this knob with the default as
it is in HEAD to improve our odds of actually getting reports. The future
priv(9) to further restrict the sysctl WILL NOT BE MERGED BACK, so the knob
will be a faithful reversion on stable/12. We will go into the merge
acknowledging that the sysctl default may be flipped back to restore
historical behavior at *any* point if it's warranted.
[0] https://www.freebsd.org/security/advisories/FreeBSD-SA-19:10.ufs.asc
PR: 246412
Reviewed by: mckusick, kib, emaste, jilles, cy, phk, imp (all previous)
Reviewed by: rgrimes (latest version)
MFC after: 1 month (note the MFC plan mentioned above)
Relnotes: absolutely, but will amend previous RELNOTES entry
Differential Revision: https://reviews.freebsd.org/D24596
there's no need to even mention it in shell rc files. Not that it's wrong;
just pointless and somewhat misleading.
Reviewed by: jilles
MFC after: 2 weeks
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D18809
This fixes the build and I will redo these changes as part of a future review
that organizes them differently. The way I tried to do it here could be done
better. Sorry for the noise.
Approved by: will (mentor)
Differential Revision: https://reviews.freebsd.org/D16737
This moves the symlink creation to after where the files are installed.
This also inverts the shell change so that it only happens if MK_TCSH is on.
Approved by: will (mentor)
Differential Revision: https://reviews.freebsd.org/D16725
This simplifies pkgbase by migrating these to CONFS so they are properly
tagged as config files.
Approved by: will (mentor)
Differential Revision: https://reviews.freebsd.org/D16708
This is the same issue as r297997, but was missed in it.
The WARNS value changes between 'build-tools' (MK_WARNS=no) and
'everything' resulting in a rebuild of this file.
Approved by: re (implicit)
Sponsored by: EMC / Isilon Storage Division
is invalid. It is used to find the size of allocated memory. As malloc may
allocate memory with mmap it will fail to take this memory into account.
Obtained from: brooks
This avoids 'build command changed' due to CFLAGS/CC changes during the
normal build. Without this the build-tools targets end up rebuilding
for the *target* rather than keeping the native versions built in
build-tools.
Sponsored by: EMC / Isilon Storage Division
At least for ncurses this fixes a build error due to it trying to run
'ccache --version' to work around a gcc 5 bug using the fix in r287205.
Sponsored by: EMC / Isilon Storage Division
libraries (such as libthr) which maintain their own signal state. This
change adds the tcsh SAVESIGVEC option to save and restore the sigvecs for
the signals the child modifies before it execs.
Reviewed by: kib, rwatson
Reported by: kib
These are no longer needed after the recent 'beforebuild: depend' changes
and hooking DIRDEPS_BUILD into a subset of FAST_DEPEND which supports
skipping 'make depend'.
Sponsored by: EMC / Isilon Storage Division
Note: tcsh(1) has a MK_TCSH=no test, so this should be a separate
package, which requires pre-install/post-install scripts, to be
added later.
Sponsored by: The FreeBSD Foundation
The symbols of libiconv from ports were changed to
have prefixed.
Since we have iconv in our libc these days, we don't
need it on 10.X and later. However, 9.X still need
this.
Spotted by: Yoshihiko Sarumaru
MFC after: 1 days
Off by default, build behaves normally.
WITH_META_MODE we get auto objdir creation, the ability to
start build from anywhere in the tree.
Still need to add real targets under targets/ to build packages.
Differential Revision: D2796
Reviewed by: brooks imp
Some users build FreeBSD as non-root in Perforce workspaces. By default,
Perforce sets files read-only unless they're explicitly being edited.
As a result, the -f argument must be used to cp in order to override the
read-only flag when copying source files to object directories. Bare use of
'cp' should be avoided in the future.
Update all current users of 'cp' in the src tree.
Reviewed by: emaste
MFC after: 1 week
Sponsored by: Spectra Logic
Makefiles should not assume that source files can be overwritten. This is the
common case for Perforce source trees.
This is a followup commit to r211243 in the same vein.
MFC after: 1 month
Sponsored by: Spectra Logic
MFSpectraBSD: r1036319 on 2014/01/29, r1046711 on 2014/03/06
variants. This allows usable file system images (i.e. those with both a
shell and an editor) to be created with only one copy of the curses library.
Exp-run: antoine
PR: 189842
Discussed with: bapt
Sponsored by: DARPA, AFRL
