linux/security/apparmor
Gustavo A. R. Silva fe9fd23e3b apparmor: Replace zero-length array with flexible-array
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

sizeof(flexible-array-member) triggers a warning because flexible array
members have incomplete type[1]. There are some instances of code in
which the sizeof operator is being incorrectly/erroneously applied to
zero-length arrays and the result is zero. Such instances may be hiding
some bugs. So, this work (flexible-array member conversions) will also
help to get completely rid of those sorts of issues.

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2020-05-15 13:04:55 -07:00
..
include apparmor: add outofband transition and use it in xattr match 2020-01-21 06:00:20 -08:00
.gitignore apparmor: add base infastructure for socket mediation 2018-03-13 17:25:48 -07:00
apparmorfs.c apparmor: Replace zero-length array with flexible-array 2020-05-15 13:04:55 -07:00
audit.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441 2019-06-05 17:37:17 +02:00
capability.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441 2019-06-05 17:37:17 +02:00
crypto.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441 2019-06-05 17:37:17 +02:00
domain.c apparmor: remove duplicate check of xattrs on profile attachment. 2020-01-21 06:00:20 -08:00
file.c apparmor: only get a label reference if the fast path check fails 2020-01-02 05:31:40 -08:00
ipc.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441 2019-06-05 17:37:17 +02:00
Kconfig + Features 2019-12-03 12:51:35 -08:00
label.c apparmor: fix nnp subset test for unconfined 2020-01-21 05:58:04 -08:00
lib.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441 2019-06-05 17:37:17 +02:00
lsm.c + Features 2019-12-03 12:51:35 -08:00
Makefile apparmor: add base infastructure for socket mediation 2018-03-13 17:25:48 -07:00
match.c apparmor: ensure that dfa state tables have entries 2020-04-08 04:42:48 -07:00
mount.c apparmor: fix bind mounts aborting with -ENOMEM 2020-01-02 05:31:40 -08:00
net.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441 2019-06-05 17:37:17 +02:00
nulldfa.in apparmor: cleanup add proper line wrapping to nulldfa.in 2018-02-09 11:30:01 -08:00
path.c AppArmor: Remove semicolon 2020-01-18 15:36:58 -08:00
policy_ns.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441 2019-06-05 17:37:17 +02:00
policy_unpack.c apparmor: fail unpack if profile mode is unknown 2020-01-21 05:58:53 -08:00
policy.c apparmor: fix aa_xattrs_match() may sleep while holding a RCU lock 2020-01-04 15:56:44 -08:00
procattr.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441 2019-06-05 17:37:17 +02:00
resource.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441 2019-06-05 17:37:17 +02:00
secid.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441 2019-06-05 17:37:17 +02:00
stacksplitdfa.in apparmor: use the dfa to do label parse string splitting 2018-02-09 11:30:01 -08:00
task.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441 2019-06-05 17:37:17 +02:00