From 8c104f26fd3064f4af002cccaf9758742aa918ea Mon Sep 17 00:00:00 2001
From: John Johansen <john.johansen@canonical.com>
Date: Mon, 20 Nov 2017 23:24:09 -0800
Subject: [PATCH] apparmor: fix possible recursive lock warning in __aa_create_ns
References: Git-fixes, bsc#1079834
Git-commit: feb3c766a3ab32d233aaff7db13afd9ba5bc142d
Patch-mainline: v4.15-rc1
Use mutex_lock_nested to provide lockdep the parent child lock ordering of
the tree.
This fixes the lockdep Warning
[ 305.275177] ============================================
[ 305.275178] WARNING: possible recursive locking detected
[ 305.275179] 4.14.0-rc7+ #320 Not tainted
[ 305.275180] --------------------------------------------
[ 305.275181] apparmor_parser/1339 is trying to acquire lock:
[ 305.275182] (&ns->lock){+.+.}, at: [<ffffffff970544dd>] __aa_create_ns+0x6d/0x1e0
[ 305.275187]
but task is already holding lock:
[ 305.275187] (&ns->lock){+.+.}, at: [<ffffffff97054b5d>] aa_prepare_ns+0x3d/0xd0
[ 305.275190]
other info that might help us debug this:
[ 305.275191] Possible unsafe locking scenario:
[ 305.275192] CPU0
[ 305.275193] ----
[ 305.275193] lock(&ns->lock);
[ 305.275194] lock(&ns->lock);
[ 305.275195]
*** DEADLOCK ***
[ 305.275196] May be due to missing lock nesting notation
[ 305.275198] 2 locks held by apparmor_parser/1339:
[ 305.275198] #0: (sb_writers#10){.+.+}, at: [<ffffffff96e9c6b7>] vfs_write+0x1a7/0x1d0
[ 305.275202] #1: (&ns->lock){+.+.}, at: [<ffffffff97054b5d>] aa_prepare_ns+0x3d/0xd0
[ 305.275205]
stack backtrace:
[ 305.275207] CPU: 1 PID: 1339 Comm: apparmor_parser Not tainted 4.14.0-rc7+ #320
[ 305.275208] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.1-1ubuntu1 04/01/2014
[ 305.275209] Call Trace:
[ 305.275212] dump_stack+0x85/0xcb
[ 305.275214] __lock_acquire+0x141c/0x1460
[ 305.275216] ? __aa_create_ns+0x6d/0x1e0
[ 305.275218] ? ___slab_alloc+0x183/0x540
[ 305.275219] ? ___slab_alloc+0x183/0x540
[ 305.275221] lock_acquire+0xed/0x1e0
[ 305.275223] ? lock_acquire+0xed/0x1e0
[ 305.275224] ? __aa_create_ns+0x6d/0x1e0
[ 305.275227] __mutex_lock+0x89/0x920
[ 305.275228] ? __aa_create_ns+0x6d/0x1e0
[ 305.275230] ? trace_hardirqs_on_caller+0x11f/0x190
[ 305.275231] ? __aa_create_ns+0x6d/0x1e0
[ 305.275233] ? __lockdep_init_map+0x57/0x1d0
[ 305.275234] ? lockdep_init_map+0x9/0x10
[ 305.275236] ? __rwlock_init+0x32/0x60
[ 305.275238] mutex_lock_nested+0x1b/0x20
[ 305.275240] ? mutex_lock_nested+0x1b/0x20
[ 305.275241] __aa_create_ns+0x6d/0x1e0
[ 305.275243] aa_prepare_ns+0xc2/0xd0
[ 305.275245] aa_replace_profiles+0x168/0xf30
[ 305.275247] ? __might_fault+0x85/0x90
[ 305.275250] policy_update+0xb9/0x380
[ 305.275252] profile_load+0x7e/0x90
[ 305.275254] __vfs_write+0x28/0x150
[ 305.275256] ? rcu_read_lock_sched_held+0x72/0x80
[ 305.275257] ? rcu_sync_lockdep_assert+0x2f/0x60
[ 305.275259] ? __sb_start_write+0xdc/0x1c0
[ 305.275261] ? vfs_write+0x1a7/0x1d0
[ 305.275262] vfs_write+0xca/0x1d0
[ 305.275264] ? trace_hardirqs_on_caller+0x11f/0x190
[ 305.275266] SyS_write+0x49/0xa0
[ 305.275268] entry_SYSCALL_64_fastpath+0x23/0xc2
[ 305.275271] RIP: 0033:0x7fa6b22e8c74
[ 305.275272] RSP: 002b:00007ffeaaee6288 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[ 305.275273] RAX: ffffffffffffffda RBX: 00007ffeaaee62a4 RCX: 00007fa6b22e8c74
[ 305.275274] RDX: 0000000000000a51 RSI: 00005566a8198c10 RDI: 0000000000000004
[ 305.275275] RBP: 0000000000000a39 R08: 0000000000000a51 R09: 0000000000000000
[ 305.275276] R10: 0000000000000000 R11: 0000000000000246 R12: 00005566a8198c10
[ 305.275277] R13: 0000000000000004 R14: 00005566a72ecb88 R15: 00005566a72ec3a8
Fixes: 73688d1ed0b8 ("apparmor: refactor prepare_ns() and make usable from different views")
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
---
security/apparmor/apparmorfs.c | 22 +++++++++++-----------
security/apparmor/label.c | 2 +-
security/apparmor/policy.c | 8 ++++----
security/apparmor/policy_ns.c | 8 ++++----
security/apparmor/policy_unpack.c | 2 +-
5 files changed, 21 insertions(+), 21 deletions(-)
diff --git a/security/apparmor/apparmorfs.c b/security/apparmor/apparmorfs.c
index 518d5928661b..1ccd0139a088 100644
--- a/security/apparmor/apparmorfs.c
+++ b/security/apparmor/apparmorfs.c
@@ -533,7 +533,7 @@ static ssize_t ns_revision_read(struct file *file, char __user *buf,
long last_read;
int avail;
- mutex_lock(&rev->ns->lock);
+ mutex_lock_nested(&rev->ns->lock, rev->ns->level);
last_read = rev->last_read;
if (last_read == rev->ns->revision) {
mutex_unlock(&rev->ns->lock);
@@ -543,7 +543,7 @@ static ssize_t ns_revision_read(struct file *file, char __user *buf,
last_read !=
READ_ONCE(rev->ns->revision)))
return -ERESTARTSYS;
- mutex_lock(&rev->ns->lock);
+ mutex_lock_nested(&rev->ns->lock, rev->ns->level);
}
avail = sprintf(buffer, "%ld\n", rev->ns->revision);
@@ -577,7 +577,7 @@ static unsigned int ns_revision_poll(struct file *file, poll_table *pt)
unsigned int mask = 0;
if (rev) {
- mutex_lock(&rev->ns->lock);
+ mutex_lock_nested(&rev->ns->lock, rev->ns->level);
poll_wait(file, &rev->ns->wait, pt);
if (rev->last_read < rev->ns->revision)
mask |= POLLIN | POLLRDNORM;
@@ -1643,7 +1643,7 @@ static int ns_mkdir_op(struct inode *dir, struct dentry *dentry, umode_t mode)
*/
inode_unlock(dir);
error = simple_pin_fs(&aafs_ops, &aafs_mnt, &aafs_count);
- mutex_lock(&parent->lock);
+ mutex_lock_nested(&parent->lock, parent->level);
inode_lock_nested(dir, I_MUTEX_PARENT);
if (error)
goto out;
@@ -1692,7 +1692,7 @@ static int ns_rmdir_op(struct inode *dir, struct dentry *dentry)
inode_unlock(dir);
inode_unlock(dentry->d_inode);
- mutex_lock(&parent->lock);
+ mutex_lock_nested(&parent->lock, parent->level);
ns = aa_get_ns(__aa_findn_ns(&parent->sub_ns, dentry->d_name.name,
dentry->d_name.len));
if (!ns) {
@@ -1747,7 +1747,7 @@ void __aafs_ns_rmdir(struct aa_ns *ns)
__aafs_profile_rmdir(child);
list_for_each_entry(sub, &ns->sub_ns, base.list) {
- mutex_lock(&sub->lock);
+ mutex_lock_nested(&sub->lock, sub->level);
__aafs_ns_rmdir(sub);
mutex_unlock(&sub->lock);
}
@@ -1877,7 +1877,7 @@ int __aafs_ns_mkdir(struct aa_ns *ns, struct dentry *parent, const char *name,
/* subnamespaces */
list_for_each_entry(sub, &ns->sub_ns, base.list) {
- mutex_lock(&sub->lock);
+ mutex_lock_nested(&sub->lock, sub->level);
error = __aafs_ns_mkdir(sub, ns_subns_dir(ns), NULL, NULL);
mutex_unlock(&sub->lock);
if (error)
@@ -1921,7 +1921,7 @@ static struct aa_ns *__next_ns(struct aa_ns *root, struct aa_ns *ns)
/* is next namespace a child */
if (!list_empty(&ns->sub_ns)) {
next = list_first_entry(&ns->sub_ns, typeof(*ns), base.list);
- mutex_lock(&next->lock);
+ mutex_lock_nested(&next->lock, next->level);
return next;
}
@@ -1931,7 +1931,7 @@ static struct aa_ns *__next_ns(struct aa_ns *root, struct aa_ns *ns)
mutex_unlock(&ns->lock);
next = list_next_entry(ns, base.list);
if (!list_entry_is_head(next, &parent->sub_ns, base.list)) {
- mutex_lock(&next->lock);
+ mutex_lock_nested(&next->lock, next->level);
return next;
}
ns = parent;
@@ -2039,7 +2039,7 @@ static void *p_start(struct seq_file *f, loff_t *pos)
f->private = root;
/* find the first profile */
- mutex_lock(&root->lock);
+ mutex_lock_nested(&root->lock, root->level);
profile = __first_profile(root, root);
/* skip to position */
@@ -2492,7 +2492,7 @@ static int __init aa_create_aafs(void)
ns_subrevision(root_ns) = dent;
/* policy tree referenced by magic policy symlink */
- mutex_lock(&root_ns->lock);
+ mutex_lock_nested(&root_ns->lock, root_ns->level);
error = __aafs_ns_mkdir(root_ns, aafs_mnt->mnt_root, ".policy",
aafs_mnt->mnt_root);
mutex_unlock(&root_ns->lock);
diff --git a/security/apparmor/label.c b/security/apparmor/label.c
index c5b99b954580..f5df9eaba4df 100644
--- a/security/apparmor/label.c
+++ b/security/apparmor/label.c
@@ -2115,7 +2115,7 @@ void __aa_labelset_update_subtree(struct aa_ns *ns)
__labelset_update(ns);
list_for_each_entry(child, &ns->sub_ns, base.list) {
- mutex_lock(&child->lock);
+ mutex_lock_nested(&child->lock, child->level);
__aa_labelset_update_subtree(child);
mutex_unlock(&child->lock);
}
diff --git a/security/apparmor/policy.c b/security/apparmor/policy.c
index 877983014b5b..a6e84d19bc0b 100644
--- a/security/apparmor/policy.c
+++ b/security/apparmor/policy.c
@@ -546,7 +546,7 @@ struct aa_profile *aa_new_null_profile(struct aa_profile *parent, bool hat,
profile->file.dfa = aa_get_dfa(nulldfa);
profile->policy.dfa = aa_get_dfa(nulldfa);
- mutex_lock(&profile->ns->lock);
+ mutex_lock_nested(&profile->ns->lock, profile->ns->level);
p = __find_child(&parent->base.profiles, bname);
if (p) {
aa_free_profile(profile);
@@ -907,7 +907,7 @@ ssize_t aa_replace_profiles(struct aa_ns *policy_ns, struct aa_label *label,
} else
ns = aa_get_ns(policy_ns ? policy_ns : labels_ns(label));
- mutex_lock(&ns->lock);
+ mutex_lock_nested(&ns->lock, ns->level);
/* check for duplicate rawdata blobs: space and file dedup */
list_for_each_entry(rawdata_ent, &ns->rawdata_list, list) {
if (aa_rawdata_eq(rawdata_ent, udata)) {
@@ -1118,13 +1118,13 @@ ssize_t aa_remove_profiles(struct aa_ns *policy_ns, struct aa_label *subj,
if (!name) {
/* remove namespace - can only happen if fqname[0] == ':' */
- mutex_lock(&ns->parent->lock);
+ mutex_lock_nested(&ns->parent->lock, ns->level);
__aa_remove_ns(ns);
__aa_bump_ns_revision(ns);
mutex_unlock(&ns->parent->lock);
} else {
/* remove profile */
- mutex_lock(&ns->lock);
+ mutex_lock_nested(&ns->lock, ns->level);
profile = aa_get_profile(__lookup_profile(&ns->base, name));
if (!profile) {
error = -ENOENT;
diff --git a/security/apparmor/policy_ns.c b/security/apparmor/policy_ns.c
index 62a3589c62ab..b1e629cba70b 100644
--- a/security/apparmor/policy_ns.c
+++ b/security/apparmor/policy_ns.c
@@ -256,7 +256,8 @@ static struct aa_ns *__aa_create_ns(struct aa_ns *parent, const char *name,
ns = alloc_ns(parent->base.hname, name);
if (!ns)
return NULL;
- mutex_lock(&ns->lock);
+ ns->level = parent->level + 1;
+ mutex_lock_nested(&ns->lock, ns->level);
error = __aafs_ns_mkdir(ns, ns_subns_dir(parent), name, dir);
if (error) {
AA_ERROR("Failed to create interface for ns %s\n",
@@ -266,7 +267,6 @@ static struct aa_ns *__aa_create_ns(struct aa_ns *parent, const char *name,
return ERR_PTR(error);
}
ns->parent = aa_get_ns(parent);
- ns->level = parent->level + 1;
list_add_rcu(&ns->base.list, &parent->sub_ns);
/* add list ref */
aa_get_ns(ns);
@@ -313,7 +313,7 @@ struct aa_ns *aa_prepare_ns(struct aa_ns *parent, const char *name)
{
struct aa_ns *ns;
- mutex_lock(&parent->lock);
+ mutex_lock_nested(&parent->lock, parent->level);
/* try and find the specified ns and if it doesn't exist create it */
/* released by caller */
ns = aa_get_ns(__aa_find_ns(&parent->sub_ns, name));
@@ -336,7 +336,7 @@ static void destroy_ns(struct aa_ns *ns)
if (!ns)
return;
- mutex_lock(&ns->lock);
+ mutex_lock_nested(&ns->lock, ns->level);
/* release all profiles in this namespace */
__aa_profile_list_release(&ns->base.profiles);
diff --git a/security/apparmor/policy_unpack.c b/security/apparmor/policy_unpack.c
index c02e2b9472bb..2b51fca5057d 100644
--- a/security/apparmor/policy_unpack.c
+++ b/security/apparmor/policy_unpack.c
@@ -157,7 +157,7 @@ static void do_loaddata_free(struct work_struct *work)
struct aa_ns *ns = aa_get_ns(d->ns);
if (ns) {
- mutex_lock(&ns->lock);
+ mutex_lock_nested(&ns->lock, ns->level);
__aa_fs_remove_rawdata(d);
mutex_unlock(&ns->lock);
aa_put_ns(ns);
--
2.16.1