From 86812bb0de1a3758dc6c7aa01a763158a7c0638a Mon Sep 17 00:00:00 2001 From: Casey Schaufler Date: Tue, 17 Apr 2012 18:55:46 -0700 Subject: [PATCH 1/3] Smack: move label list initialization A kernel with Smack enabled will fail if tmpfs has xattr support. Move the initialization of predefined Smack label list entries to the LSM initialization from the smackfs setup. This became an issue when tmpfs acquired xattr support, but was never correct. Signed-off-by: Casey Schaufler Signed-off-by: James Morris --- security/smack/smack_lsm.c | 44 ++++++++++++++++++++++++++++---------- security/smack/smackfs.c | 14 ------------ 2 files changed, 33 insertions(+), 25 deletions(-) diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index 10056f2f6df3..45c32f074166 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -3640,8 +3640,38 @@ struct security_operations smack_ops = { }; -static __init void init_smack_know_list(void) +static __init void init_smack_known_list(void) { + /* + * Initialize CIPSO locks + */ + spin_lock_init(&smack_known_huh.smk_cipsolock); + spin_lock_init(&smack_known_hat.smk_cipsolock); + spin_lock_init(&smack_known_star.smk_cipsolock); + spin_lock_init(&smack_known_floor.smk_cipsolock); + spin_lock_init(&smack_known_invalid.smk_cipsolock); + spin_lock_init(&smack_known_web.smk_cipsolock); + /* + * Initialize rule list locks + */ + mutex_init(&smack_known_huh.smk_rules_lock); + mutex_init(&smack_known_hat.smk_rules_lock); + mutex_init(&smack_known_floor.smk_rules_lock); + mutex_init(&smack_known_star.smk_rules_lock); + mutex_init(&smack_known_invalid.smk_rules_lock); + mutex_init(&smack_known_web.smk_rules_lock); + /* + * Initialize rule lists + */ + INIT_LIST_HEAD(&smack_known_huh.smk_rules); + INIT_LIST_HEAD(&smack_known_hat.smk_rules); + INIT_LIST_HEAD(&smack_known_star.smk_rules); + INIT_LIST_HEAD(&smack_known_floor.smk_rules); + INIT_LIST_HEAD(&smack_known_invalid.smk_rules); + INIT_LIST_HEAD(&smack_known_web.smk_rules); + /* + * Create the known labels list + */ list_add(&smack_known_huh.list, &smack_known_list); list_add(&smack_known_hat.list, &smack_known_list); list_add(&smack_known_star.list, &smack_known_list); @@ -3676,16 +3706,8 @@ static __init int smack_init(void) cred = (struct cred *) current->cred; cred->security = tsp; - /* initialize the smack_know_list */ - init_smack_know_list(); - /* - * Initialize locks - */ - spin_lock_init(&smack_known_huh.smk_cipsolock); - spin_lock_init(&smack_known_hat.smk_cipsolock); - spin_lock_init(&smack_known_star.smk_cipsolock); - spin_lock_init(&smack_known_floor.smk_cipsolock); - spin_lock_init(&smack_known_invalid.smk_cipsolock); + /* initialize the smack_known_list */ + init_smack_known_list(); /* * Register with LSM diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c index 5c32f36ff706..038811cb7e62 100644 --- a/security/smack/smackfs.c +++ b/security/smack/smackfs.c @@ -1614,20 +1614,6 @@ static int __init init_smk_fs(void) smk_cipso_doi(); smk_unlbl_ambient(NULL); - mutex_init(&smack_known_floor.smk_rules_lock); - mutex_init(&smack_known_hat.smk_rules_lock); - mutex_init(&smack_known_huh.smk_rules_lock); - mutex_init(&smack_known_invalid.smk_rules_lock); - mutex_init(&smack_known_star.smk_rules_lock); - mutex_init(&smack_known_web.smk_rules_lock); - - INIT_LIST_HEAD(&smack_known_floor.smk_rules); - INIT_LIST_HEAD(&smack_known_hat.smk_rules); - INIT_LIST_HEAD(&smack_known_huh.smk_rules); - INIT_LIST_HEAD(&smack_known_invalid.smk_rules); - INIT_LIST_HEAD(&smack_known_star.smk_rules); - INIT_LIST_HEAD(&smack_known_web.smk_rules); - return err; } From 09c79b60960bdd4b00916219402eabfa5e479c5a Mon Sep 17 00:00:00 2001 From: Jesper Juhl Date: Mon, 6 Feb 2012 20:07:04 +1100 Subject: [PATCH 2/3] mpi: Avoid using freed pointer in mpi_lshift_limbs() At the start of the function we assign 'a->d' to 'ap'. Then we use the RESIZE_IF_NEEDED macro on 'a' - this may free 'a->d' and replace it with newly allocaetd storage. In that case, we'll be operating on freed memory further down in the function when we index into 'ap[]'. Since we don't actually need 'ap' until after the use of the RESIZE_IF_NEEDED macro we can just delay the assignment to it until after we've potentially resized, thus avoiding the issue. While I was there anyway I also changed the integer variable 'n' to be const. It might as well be since we only assign to it once and use it as a constant, and then the compiler will tell us if we ever assign to it in the future. Signed-off-by: Jesper Juhl Acked-by: Dmitry Kasatkin Signed-off-by: James Morris --- lib/mpi/mpi-bit.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/lib/mpi/mpi-bit.c b/lib/mpi/mpi-bit.c index 2f526627e4f5..0c505361da19 100644 --- a/lib/mpi/mpi-bit.c +++ b/lib/mpi/mpi-bit.c @@ -177,8 +177,8 @@ int mpi_rshift(MPI x, MPI a, unsigned n) */ int mpi_lshift_limbs(MPI a, unsigned int count) { - mpi_ptr_t ap = a->d; - int n = a->nlimbs; + const int n = a->nlimbs; + mpi_ptr_t ap; int i; if (!count || !n) @@ -187,6 +187,7 @@ int mpi_lshift_limbs(MPI a, unsigned int count) if (RESIZE_IF_NEEDED(a, n + count) < 0) return -ENOMEM; + ap = a->d; for (i = n - 1; i >= 0; i--) ap[i + count] = ap[i]; for (i = 0; i < count; i++) From d52fc5dde171f030170a6cb78034d166b13c9445 Mon Sep 17 00:00:00 2001 From: Eric Paris Date: Tue, 17 Apr 2012 16:26:54 -0400 Subject: [PATCH 3/3] fcaps: clear the same personality flags as suid when fcaps are used If a process increases permissions using fcaps all of the dangerous personality flags which are cleared for suid apps should also be cleared. Thus programs given priviledge with fcaps will continue to have address space randomization enabled even if the parent tried to disable it to make it easier to attack. Signed-off-by: Eric Paris Reviewed-by: Serge Hallyn Signed-off-by: James Morris --- security/commoncap.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/security/commoncap.c b/security/commoncap.c index 0cf4b53480a7..0ecf4ba321cb 100644 --- a/security/commoncap.c +++ b/security/commoncap.c @@ -505,6 +505,11 @@ int cap_bprm_set_creds(struct linux_binprm *bprm) } skip: + /* if we have fs caps, clear dangerous personality flags */ + if (!cap_issubset(new->cap_permitted, old->cap_permitted)) + bprm->per_clear |= PER_CLEAR_ON_SETID; + + /* Don't let someone trace a set[ug]id/setpcap binary with the revised * credentials unless they have the appropriate permit */