====================================================== WARNING: possible circular locking dependency detected 4.14.114+ #63 Not tainted ------------------------------------------------------ syz-executor.0/12780 is trying to acquire lock: (cpu_hotplug_lock.rw_sem){++++}, at: [<000000007a51719f>] get_online_cpus include/linux/cpu.h:138 [inline] (cpu_hotplug_lock.rw_sem){++++}, at: [<000000007a51719f>] lru_add_drain_all+0xa/0x20 mm/swap.c:729 but task is already holding lock: (&sb->s_type->i_mutex_key#10){+.+.}, at: [<000000009321cedf>] inode_lock include/linux/fs.h:715 [inline] (&sb->s_type->i_mutex_key#10){+.+.}, at: [<000000009321cedf>] shmem_add_seals+0x12b/0x1150 mm/shmem.c:2829 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #5 (&sb->s_type->i_mutex_key#10){+.+.}: -> #4 (ashmem_mutex){+.+.}: -> #3 (&mm->mmap_sem){++++}: -> #2 (&cpuctx_mutex){+.+.}: -> #1 (pmus_lock){+.+.}: -> #0 (cpu_hotplug_lock.rw_sem){++++}: other info that might help us debug this: Chain exists of: cpu_hotplug_lock.rw_sem --> ashmem_mutex --> &sb->s_type->i_mutex_key#10 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&sb->s_type->i_mutex_key#10); lock(ashmem_mutex); lock(&sb->s_type->i_mutex_key#10); lock(cpu_hotplug_lock.rw_sem); *** DEADLOCK *** 1 lock held by syz-executor.0/12780: #0: (&sb->s_type->i_mutex_key#10){+.+.}, at: [<000000009321cedf>] inode_lock include/linux/fs.h:715 [inline] #0: (&sb->s_type->i_mutex_key#10){+.+.}, at: [<000000009321cedf>] shmem_add_seals+0x12b/0x1150 mm/shmem.c:2829 stack backtrace: CPU: 1 PID: 12780 Comm: syz-executor.0 Not tainted 4.14.114+ #63 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0xb9/0x10e lib/dump_stack.c:53 print_circular_bug.isra.0.cold+0x2dc/0x425 kernel/locking/lockdep.c:1258 FAT-fs (loop3): Unrecognized mount option "shortnameÐÕ(Ç1" or missing value FAT-fs (loop3): Unrecognized mount option "shortnameÐÕ(Ç1" or missing value FAT-fs (loop3): Unrecognized mount option "shortnameÐÕ(Ç1" or missing value FAT-fs (loop3): Unrecognized mount option "shortnameÐÕ(Ç1" or missing value FAT-fs (loop3): Unrecognized mount option "shortnameÐÕ(Ç1" or missing value FAT-fs (loop3): Unrecognized mount option "shortnameÐÕ(Ç1" or missing value FAT-fs (loop3): Unrecognized mount option "shortnameÐÕ(Ç1" or missing value audit: type=1400 audit(276.294:316): avc: denied { associate } for pid=13190 comm="syz-executor.5" name="ashmem" dev="devtmpfs" ino=5427 scontext=system_u:object_r:hostname_exec_t:s0 tcontext=system_u:object_r:device_t:s0 tclass=filesystem permissive=1 FAT-fs (loop3): Unrecognized mount option "shortnameÐÕ(Ç1" or missing value FAT-fs (loop3): Unrecognized mount option "shortnameÐÕ(Ç1" or missing value FAT-fs (loop3): Unrecognized mount option "shortnameÐÕ(Ç1" or missing value audit: type=1400 audit(277.874:317): avc: denied { map } for pid=13395 comm="syz-executor.5" path="/dev/zero" dev="devtmpfs" ino=1030 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:zero_device_t:s0 tclass=chr_file permissive=1 FAT-fs (loop3): Unrecognized mount option "shortnameÐÕ(Ç1" or missing value audit: type=1400 audit(278.014:318): avc: denied { getattr } for pid=13423 comm="syz-executor.5" path="socket:[39802]" dev="sockfs" ino=39802 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_netfilter_socket permissive=1 FAT-fs (loop3): Unrecognized mount option "shortnameÐÕ(Ç1" or missing value FAT-fs (loop5): Unrecognized mount option "shortnameÐÕ(Ç1" or missing value FAT-fs (loop3): Unrecognized mount option "shortnameÐÕ(Ç1" or missing value FAT-fs (loop5): Unrecognized mount option "shortnameÐÕ(Ç1" or missing value FAT-fs (loop3): Unrecognized mount option "shortnameÐÕ(Ç1" or missing value FAT-fs (loop5): Unrecognized mount option "shortnameÐÕ(Ç1" or missing value FAT-fs (loop3): Unrecognized mount option "shortnameÐÕ(Ç1" or missing value FAT-fs (loop5): Unrecognized mount option "shortnameÐÕ(Ç1" or missing value FAT-fs (loop3): Unrecognized mount option "shortnameÐÕ(Ç1" or missing value FAT-fs (loop5): Unrecognized mount option "shortnameÐÕ(Ç1" or missing value FAT-fs (loop3): Unrecognized mount option "shortnameÐÕ(Ç1" or missing value FAT-fs (loop5): Unrecognized mount option "shortnameÐÕ(Ç1" or missing value FAT-fs (loop3): Unrecognized mount option "shortnameÐÕ(Ç1" or missing value FAT-fs (loop5): Unrecognized mount option "shortnameÐÕ(Ç1" or missing value FAT-fs (loop3): Unrecognized mount option "shortnameÐÕ(Ç1" or missing value FAT-fs (loop5): Unrecognized mount option "shortnameÐÕ(Ç1" or missing value FAT-fs (loop3): Unrecognized mount option "shortnameÐÕ(Ç1" or missing value FAT-fs (loop5): Unrecognized mount option "shortnameÐÕ(Ç1" or missing value FAT-fs (loop3): Unrecognized mount option "shortnameÐÕ(Ç1" or missing value FAT-fs (loop5): Unrecognized mount option "shortnameÐÕ(Ç1" or missing value FAT-fs (loop3): Unrecognized mount option "shortnameÐÕ(Ç1" or missing value FAT-fs (loop3): Unrecognized mount option "shortnameÐÕ(Ç1" or missing value FAT-fs (loop5): Unrecognized mount option "shortnameÐÕ(Ç1" or missing value FAT-fs (loop3): Unrecognized mount option "shortnameÐÕ(Ç1" or missing value FAT-fs (loop3): Unrecognized mount option "shortnameÐÕ(Ç1" or missing value FAT-fs (loop5): Unrecognized mount option "shortnameÐÕ(Ç1" or missing value FAT-fs (loop3): Unrecognized mount option "shortnameÐÕ(Ç1" or missing value FAT-fs (loop5): Unrecognized mount option "shortnameÐÕ(Ç1" or missing value FAT-fs (loop3): Unrecognized mount option "shortnameÐÕ(Ç1" or missing value FAT-fs (loop1): Unrecognized mount option "shortnameÐÕ(Ç1" or missing value FAT-fs (loop5): Unrecognized mount option "shortnameÐÕ(Ç1" or missing value FAT-fs (loop3): Unrecognized mount option "shortnameÐÕ(Ç1" or missing value FAT-fs (loop1): Unrecognized mount option "shortnameÐÕ(Ç1" or missing value FAT-fs (loop5): Unrecognized mount option "shortnameÐÕ(Ç1" or missing value FAT-fs (loop5): Unrecognized mount option "shortnameÐÕ(Ç1" or missing value FAT-fs (loop1): Unrecognized mount option "shortnameÐÕ(Ç1" or missing value FAT-fs (loop5): Unrecognized mount option "shortnameÐÕ(Ç1" or missing value FAT-fs (loop1): Unrecognized mount option "shortnameÐÕ(Ç1" or missing value FAT-fs (loop5): Unrecognized mount option "shortnameÐÕ(Ç1" or missing value FAT-fs (loop1): Unrecognized mount option "shortnameÐÕ(Ç1" or missing value FAT-fs (loop5): Unrecognized mount option "shortnameÐÕ(Ç1" or missing value FAT-fs (loop5): Unrecognized mount option "shortnameÐÕ(Ç1" or missing value FAT-fs (loop5): Unrecognized mount option "shortnameÐÕ(Ç1" or missing value FAT-fs (loop5): Unrecognized mount option "shortnameÐÕ(Ç1" or missing value