From feb3c766a3ab32d233aaff7db13afd9ba5bc142d Mon Sep 17 00:00:00 2001 From: John Johansen Date: Mon, 20 Nov 2017 23:24:09 -0800 Subject: apparmor: fix possible recursive lock warning in __aa_create_ns 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: [] __aa_create_ns+0x6d/0x1e0 [ 305.275187] but task is already holding lock: [ 305.275187] (&ns->lock){+.+.}, at: [] 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: [] vfs_write+0x1a7/0x1d0 [ 305.275202] #1: (&ns->lock){+.+.}, at: [] 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 --- security/apparmor/policy.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'security/apparmor/policy.c') diff --git a/security/apparmor/policy.c b/security/apparmor/policy.c index 586b249d3b46..b0b58848c248 100644 --- a/security/apparmor/policy.c +++ b/security/apparmor/policy.c @@ -545,7 +545,7 @@ name: 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); @@ -906,7 +906,7 @@ 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)) { @@ -1117,13 +1117,13 @@ 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; -- cgit v1.2.3