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| author | John Johansen <john.johansen@canonical.com> | 2017-11-20 23:24:09 -0800 |
|---|---|---|
| committer | John Johansen <john.johansen@canonical.com> | 2017-11-21 02:17:16 -0800 |
| commit | feb3c766a3ab32d233aaff7db13afd9ba5bc142d (patch) | |
| tree | 59b48447feb2bf23a53df1b2ead7d02fd440c957 /security/apparmor/policy.c | |
| parent | 5d7c44ef5e4f0149c9fb99faeae41e930485a1ec (diff) | |
| download | linux-feb3c766a3ab32d233aaff7db13afd9ba5bc142d.tar.gz linux-feb3c766a3ab32d233aaff7db13afd9ba5bc142d.tar.bz2 linux-feb3c766a3ab32d233aaff7db13afd9ba5bc142d.zip | |
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: [<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>
Diffstat (limited to 'security/apparmor/policy.c')
| -rw-r--r-- | security/apparmor/policy.c | 8 |
1 files changed, 4 insertions, 4 deletions
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; |