Eric Biggers 5f5fb7cea8 Smack: fix use-after-free in smk_write_relabel_self() ... commit beb4ee6770 upstream. smk_write_relabel_self() frees memory from the task's credentials with no locking, which can easily cause a use-after-free because multiple tasks can share the same credentials structure. Fix this by using prepare_creds() and commit_creds() to correctly modify the task's credentials. Reproducer for "BUG: KASAN: use-after-free in smk_write_relabel_self": #include <fcntl.h> #include <pthread.h> #include <unistd.h> static void *thrproc(void *arg) { int fd = open("/sys/fs/smackfs/relabel-self", O_WRONLY); for (;;) write(fd, "foo", 3); } int main() { pthread_t t; pthread_create(&t, NULL, thrproc, NULL); thrproc(NULL); } Reported-by: syzbot+e6416dabb497a650da40@syzkaller.appspotmail.com Fixes: 38416e5393 ("Smack: limited capability for changing process label") Cc: <stable@vger.kernel.org> # v4.4+ Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2020-08-11 15:33:35 +02:00
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apparmor	apparmor: ensure that dfa state tables have entries	2020-07-22 09:33:05 +02:00
integrity	ima: Set again build_ima_appraise variable	2020-06-22 09:31:17 +02:00
keys	mm: add kvfree_sensitive() for freeing sensitive data objects	2020-06-17 16:40:23 +02:00
loadpin	proc/sysctl: add shared variables for range check	2019-07-18 17:08:07 -07:00
lockdown	lockdown: Allow unprivileged users to see lockdown status	2020-06-22 09:30:53 +02:00
safesetid	LSM: SafeSetID: Stop releasing uninitialized ruleset	2019-09-17 11:27:05 -07:00
selinux	selinux: fix double free	2020-06-24 17:50:48 +02:00
smack	Smack: fix use-after-free in smk_write_relabel_self()	2020-08-11 15:33:35 +02:00
tomoyo	tomoyo: Use atomic_t for statistics counter	2020-02-05 21:22:41 +00:00
yama	proc/sysctl: add shared variables for range check	2019-07-18 17:08:07 -07:00
Kconfig	Merge branch 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security	2019-09-28 08:14:15 -07:00
Kconfig.hardening	meminit fix	2019-07-28 12:33:15 -07:00
Makefile	security: Add a static lockdown policy LSM	2019-08-19 21:54:15 -07:00
commoncap.c	exec: Always set cap_ambient in cap_bprm_set_creds	2020-06-03 08:21:23 +02:00
device_cgroup.c	docs: cgroup-v1: add it to the admin-guide book	2019-07-15 11:03:02 -03:00
inode.c	Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2019-07-19 10:42:02 -07:00
lsm_audit.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500	2019-06-19 17:09:55 +02:00
min_addr.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
security.c	Merge branch 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security	2019-09-28 08:14:15 -07:00