user/sven/linux.git/scripts/gcc-plugins, branch v4.13.6

randstruct: Whitelist NIU struct page overloading

2017-06-22T23:21:43Z

The NIU ethernet driver intentionally stores a page struct pointer on top of the "mapping" field. Whitelist this case: drivers/net/ethernet/sun/niu.c: In function ‘niu_rx_pkt_ignore’: drivers/net/ethernet/sun/niu.c:3402:10: note: found mismatched ssa struct pointer types: ‘struct page’ and ‘struct address_space’ *link = (struct page *) page->mapping; ~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Cc: David S. Miller Signed-off-by: Kees Cook

randstruct: Whitelist big_key path struct overloading

2017-06-22T23:21:42Z

The big_key payload structure intentionally stores a struct path in two void pointers to avoid header soup. Whitelist this case: security/keys/big_key.c: In function ‘big_key_read’: security/keys/big_key.c:293:16: note: found mismatched rhs struct pointer types: ‘struct path’ and ‘void *’ struct path *path = (struct path *)&key->payload.data[big_key_path]; ^~~~ Cc: David Howells Signed-off-by: Kees Cook

randstruct: Whitelist UNIXCB cast

2017-06-22T23:21:41Z

This is another false positive in bad cast detection: net/unix/af_unix.c: In function ‘unix_skb_scm_eq’: net/unix/af_unix.c:1621:31: note: found mismatched rhs struct pointer types: ‘struct unix_skb_parms’ and ‘char’ const struct unix_skb_parms *u = &UNIXCB(skb); ^ UNIXCB is: #define UNIXCB(skb) (*(struct unix_skb_parms *)&((skb)->cb)) And ->cb is: char cb[48] __aligned(8); This is a rather crazy cast, but appears to be safe in the face of randomization, so whitelist it in the plugin. Cc: Hannes Frederic Sowa Cc: David S. Miller Signed-off-by: Kees Cook

randstruct: Whitelist struct security_hook_heads cast

2017-06-22T23:21:40Z

The LSM initialization routines walk security_hook_heads as an array of struct list_head instead of via names to avoid a ton of needless source. Whitelist this to avoid the false positive warning from the plugin: security/security.c: In function ‘security_init’: security/security.c:59:20: note: found mismatched op0 struct pointer types: ‘struct list_head’ and ‘struct security_hook_heads’ struct list_head *list = (struct list_head *) &security_hook_heads; ^ Cc: Tetsuo Handa Cc: James Morris Signed-off-by: Kees Cook

gcc-plugins: Add the randstruct plugin

2017-06-22T23:15:45Z

This randstruct plugin is modified from Brad Spengler/PaX Team's code in the last public patch of grsecurity/PaX based on my understanding of the code. Changes or omissions from the original code are mine and don't reflect the original grsecurity/PaX code. The randstruct GCC plugin randomizes the layout of selected structures at compile time, as a probabilistic defense against attacks that need to know the layout of structures within the kernel. This is most useful for "in-house" kernel builds where neither the randomization seed nor other build artifacts are made available to an attacker. While less useful for distribution kernels (where the randomization seed must be exposed for third party kernel module builds), it still has some value there since now all kernel builds would need to be tracked by an attacker. In more performance sensitive scenarios, GCC_PLUGIN_RANDSTRUCT_PERFORMANCE can be selected to make a best effort to restrict randomization to cacheline-sized groups of elements, and will not randomize bitfields. This comes at the cost of reduced randomization. Two annotations are defined,__randomize_layout and __no_randomize_layout, which respectively tell the plugin to either randomize or not to randomize instances of the struct in question. Follow-on patches enable the auto-detection logic for selecting structures for randomization that contain only function pointers. It is disabled here to assist with bisection. Since any randomized structs must be initialized using designated initializers, __randomize_layout includes the __designated_init annotation even when the plugin is disabled so that all builds will require the needed initialization. (With the plugin enabled, annotations for automatically chosen structures are marked as well.) The main differences between this implemenation and grsecurity are: - disable automatic struct selection (to be enabled in follow-up patch) - add designated_init attribute at runtime and for manual marking - clarify debugging output to differentiate bad cast warnings - add whitelisting infrastructure - support gcc 7's DECL_ALIGN and DECL_MODE changes (Laura Abbott) - raise minimum required GCC version to 4.7 Earlier versions of this patch series were ported by Michael Leibowitz. Signed-off-by: Kees Cook

gcc-plugins: Detail c-common.h location for GCC 4.6

2017-05-28T17:23:02Z

The c-common.h file moved in stock gcc 4.7, not gcc 4.6. However, most people building plugins with gcc 4.6 are using the Debian or Ubuntu version, which includes a patch to move the headers to the 4.7 location. In case anyone trips over this with a stock gcc 4.6, add a pointer to the patch used by Debian/Ubuntu. Signed-off-by: Kees Cook

Merge tag 'gcc-plugins-v4.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

2017-03-10T02:05:41Z

Pull gcc-plugins fix from Kees Cook: "Fixes a typo in sancov plugin, exposed in earlier compiler versions" * tag 'gcc-plugins-v4.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: gcc-plugins: fix sancov_plugin for gcc-5

gcc-plugins: fix sancov_plugin for gcc-5

2017-02-27T22:10:10Z

The name of the local variable was inadvertantly changed from sancov_plugin_pass_info to sancov_pass_info: scripts/gcc-plugins/sancov_plugin.c: In function ‘int plugin_init(plugin_name_args*, plugin_gcc_version*)’: scripts/gcc-plugins/sancov_plugin.c:136:67: error: ‘sancov_plugin_pass_info’ was not declared in this scope This changes the conditional reference to this variable as well. Fixes: 5a45a4c5c3f5 ("gcc-plugins: consolidate on PASS_INFO macro") Signed-off-by: Arnd Bergmann Signed-off-by: Kees Cook

Merge branch 'for-next/gcc-plugin/structleak' into for-linus/gcc-plugins

2017-02-22T05:12:57Z

gcc-plugins: Add structleak for more stack initialization

2017-01-18T20:02:35Z

This plugin detects any structures that contain __user attributes and makes sure it is being fully initialized so that a specific class of information exposure is eliminated. (This plugin was originally designed to block the exposure of siginfo in CVE-2013-2141.) Ported from grsecurity/PaX. This version adds a verbose option to the plugin and the Kconfig. Signed-off-by: Kees Cook