KASAN: stack-out-of-bounds Read in apparmor_cred

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KASAN: stack-out-of-bounds Read in apparmor_cred_prepare	0 (2)	2019/06/16 01:13

================================================================== BUG: KASAN: stack-out-of-bounds in aa_get_newest_label security/apparmor/include/label.h:429 [inline] BUG: KASAN: stack-out-of-bounds in apparmor_cred_prepare+0x562/0x5a0 security/apparmor/lsm.c:80 kasan: CONFIG_KASAN_INLINE enabled Read of size 8 at addr ffff8881da9c0c20 by task udevd/5686 kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN CPU: 1 PID: 5686 Comm: udevd Not tainted 4.20.0-rc6+ #350 CPU: 0 PID: 5793 Comm: syz-executor3 Not tainted 4.20.0-rc6+ #350 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: RIP: 0010:lookup_object lib/debugobjects.c:156 [inline] RIP: 0010:debug_object_deactivate+0x191/0x450 lib/debugobjects.c:542 __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x244/0x39d lib/dump_stack.c:113 ------------[ cut here ]------------ Bad or missing usercopy whitelist? Kernel memory overwrite attempt detected to SLAB object '' (offset 18446744069414893726, size 2)! WARNING: CPU: 0 PID: 5793 at mm/usercopy.c:83 usercopy_warn+0xee/0x110 mm/usercopy.c:78 Kernel panic - not syncing: panic_on_warn set ... print_address_description.cold.7+0x9/0x1ff mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.8+0x242/0x309 mm/kasan/report.c:412 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433 aa_get_newest_label security/apparmor/include/label.h:429 [inline] apparmor_cred_prepare+0x562/0x5a0 security/apparmor/lsm.c:80 security_prepare_creds+0x60/0xc0 security/security.c:1022 prepare_creds+0x3b9/0x4d0 kernel/cred.c:278 do_coredump+0x52f/0x4001 fs/coredump.c:574 get_signal+0x9ee/0x1980 kernel/signal.c:2511 do_signal+0x9c/0x21c0 arch/x86/kernel/signal.c:816 exit_to_usermode_loop+0x2e5/0x380 arch/x86/entry/common.c:162 prepare_exit_to_usermode+0x342/0x3b0 arch/x86/entry/common.c:197 retint_user+0x8/0x18 RIP: 0033:0x7fd2ffc90945 Code: 3b 10 f1 ff 1f c8 09 c9 da 81 88 ff ff 00 00 00 00 00 00 00 00 50 09 c9 da 81 88 ff ff 04 f6 b1 86 ff ff ff ff e0 f5 b1 86 ff <ff> ff ff 01 00 00 00 00 00 00 00 f0 09 c9 da 81 88 ff ff 63 db bf RSP: 002b:00007ffd55eabe48 EFLAGS: 00010246 RAX: 0000000000000001 RBX: 00000000007c2110 RCX: 00007fd2ffc90943 RDX: 0000000000000004 RSI: 00007ffd55eabea0 RDI: 0000000000000004 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 0000000000000001 R13: 00000000007d3a00 R14: 00000000007c2250 R15: 000000000000000b The buggy address belongs to the object at ffff8881da9c0040 which belongs to the cache @‰ЫўЃ€яя of size -30591 The buggy address is located 33631 bytes to the right of -30591-byte region [ffff8881da9c0040, ffff8881da9b88c1) The buggy address belongs to the page: page:ffffea00076a7000 count:1 mapcount:0 mapping:ffff8881da800ac0 index:0x0 compound_mapcount: 0 flags: 0x2fffc0000010200(slab|head) raw: 02fffc0000010200 ffffea00076a4108 ffffea0007650a08 ffff8881da800ac0 raw: 0000000000000000 ffff8881da9c0040 0000000100000007 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8881da9c0b00: f1 00 f2 f2 f2 f2 f2 f2 f2 f8 f2 f2 f2 00 00 00 ffff8881da9c0b80: 00 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 >ffff8881da9c0c00: f1 f8 f2 f2 f2 00 00 00 00 00 00 00 00 00 00 00 ^ ffff8881da9c0c80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc 00 ffff8881da9c0d00: 00 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 ================================================================== Kernel Offset: disabled ====================================================== WARNING: possible circular locking dependency detected 4.20.0-rc6+ #350 Not tainted ------------------------------------------------------ syz-executor3/5793 is trying to acquire lock: 000000004475e30b ((console_sem).lock){-.-.}, at: down_trylock+0x13/0x70 kernel/locking/semaphore.c:136 but task is already holding lock: 0000000033b07c4a (&obj_hash[i].lock){-.-.}, at: debug_object_deactivate+0xf7/0x450 lib/debugobjects.c:540 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&obj_hash[i].lock){-.-.}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x99/0xd0 kernel/locking/spinlock.c:152 __debug_object_init+0x127/0x1290 lib/debugobjects.c:383 debug_object_init+0x16/0x20 lib/debugobjects.c:431 debug_hrtimer_init kernel/time/hrtimer.c:410 [inline] debug_init kernel/time/hrtimer.c:458 [inline] hrtimer_init+0x97/0x490 kernel/time/hrtimer.c:1308 init_dl_task_timer+0x1b/0x50 kernel/sched/deadline.c:1057 __sched_fork+0x2ae/0x590 kernel/sched/core.c:2166 init_idle+0x75/0x740 kernel/sched/core.c:5374 sched_init+0xb33/0xc07 kernel/sched/core.c:6063 start_kernel+0x4c1/0xa30 init/main.c:608 x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:470 x86_64_start_kernel+0x76/0x79 arch/x86/kernel/head64.c:451 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243 -> #2 (&rq->lock){-.-.}: __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2d/0x40 kernel/locking/spinlock.c:144 rq_lock kernel/sched/sched.h:1124 [inline] task_fork_fair+0xb0/0x6d0 kernel/sched/fair.c:9802 sched_fork+0x443/0xba0 kernel/sched/core.c:2359 copy_process+0x25b8/0x87a0 kernel/fork.c:1887 _do_fork+0x1cb/0x11d0 kernel/fork.c:2216 kernel_thread+0x34/0x40 kernel/fork.c:2275 rest_init+0x28/0x372 init/main.c:409 arch_call_rest_init+0xe/0x1b start_kernel+0x9f5/0xa30 init/main.c:745 x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:470 x86_64_start_kernel+0x76/0x79 arch/x86/kernel/head64.c:451 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243 -> #1 (&p->pi_lock){-.-.}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x99/0xd0 kernel/locking/spinlock.c:152 try_to_wake_up+0xdc/0x1440 kernel/sched/core.c:1965 wake_up_process+0x10/0x20 kernel/sched/core.c:2129 __up.isra.1+0x1c0/0x2a0 kernel/locking/semaphore.c:262 up+0x13c/0x1c0 kernel/locking/semaphore.c:187 __up_console_sem+0xbe/0x1b0 kernel/printk/printk.c:236 console_unlock+0x811/0x1190 kernel/printk/printk.c:2432 vprintk_emit+0x391/0x990 kernel/printk/printk.c:1922 vprintk_default+0x28/0x30 kernel/printk/printk.c:1964 vprintk_func+0x7e/0x181 kernel/printk/printk_safe.c:398 printk+0xa7/0xcf kernel/printk/printk.c:1997 check_stack_usage kernel/exit.c:755 [inline] do_exit.cold.18+0x57/0x16f kernel/exit.c:916 do_group_exit+0x177/0x440 kernel/exit.c:970 __do_sys_exit_group kernel/exit.c:981 [inline] __se_sys_exit_group kernel/exit.c:979 [inline] __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:979 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #0 ((console_sem).lock){-.-.}: other info that might help us debug this: Chain exists of: (console_sem).lock --> &rq->lock --> &obj_hash[i].lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&obj_hash[i].lock); lock(&rq->lock); lock(&obj_hash[i].lock); lock((console_sem).lock); *** DEADLOCK *** 5 locks held by syz-executor3/5793: #0: 00000000ced00a2c (rcu_read_lock){....}, at: __skb_unlink include/linux/skbuff.h:1922 [inline] #0: 00000000ced00a2c (rcu_read_lock){....}, at: __skb_dequeue include/linux/skbuff.h:1938 [inline] #0: 00000000ced00a2c (rcu_read_lock){....}, at: process_backlog+0x1dd/0x7a0 net/core/dev.c:5921 #1: 00000000ced00a2c (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2155 [inline] #1: 00000000ced00a2c (rcu_read_lock){....}, at: ip_local_deliver_finish+0x13d/0x390 net/ipv4/ip_input.c:231 #2: 000000006ec779e6 (hrtimer_bases.lock){-.-.}, at: hrtimer_interrupt+0xfc/0x780 kernel/time/hrtimer.c:1499 #3: 0000000033b07c4a (&obj_hash[i].lock){-.-.}, at: debug_object_deactivate+0xf7/0x450 lib/debugobjects.c:540 #4: 00000000ced00a2c (rcu_read_lock){....}, at: atomic_notifier_call_chain+0x0/0x190 kernel/notifier.c:329 stack backtrace: CPU: 0 PID: 5793 Comm: syz-executor3 Not tainted 4.20.0-rc6+ #350 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: Rebooting in 86400 seconds..