============================= WARNING: suspicious RCU usage 4.14.153+ #0 Not tainted ----------------------------- include/linux/radix-tree.h:238 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 2 locks held by syz-executor.1/30406: #0: (&sb->s_type->i_mutex_key#10){+.+.}, at: [<000000002c3c44b9>] inode_lock include/linux/fs.h:724 [inline] #0: (&sb->s_type->i_mutex_key#10){+.+.}, at: [<000000002c3c44b9>] shmem_add_seals+0x12b/0xf80 mm/shmem.c:2831 #1: (&(&mapping->tree_lock)->rlock){-.-.}, at: [<00000000781e34b3>] spin_lock_irq include/linux/spinlock.h:342 [inline] #1: (&(&mapping->tree_lock)->rlock){-.-.}, at: [<00000000781e34b3>] shmem_tag_pins mm/shmem.c:2685 [inline] #1: (&(&mapping->tree_lock)->rlock){-.-.}, at: [<00000000781e34b3>] shmem_wait_for_pins mm/shmem.c:2726 [inline] #1: (&(&mapping->tree_lock)->rlock){-.-.}, at: [<00000000781e34b3>] shmem_add_seals+0x2e1/0xf80 mm/shmem.c:2843 stack backtrace: CPU: 0 PID: 30406 Comm: syz-executor.1 Not tainted 4.14.153+ #0 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0xca/0x134 lib/dump_stack.c:53 radix_tree_deref_slot include/linux/radix-tree.h:238 [inline] shmem_tag_pins mm/shmem.c:2687 [inline] shmem_wait_for_pins mm/shmem.c:2726 [inline] shmem_add_seals+0x9d2/0xf80 mm/shmem.c:2843 shmem_fcntl+0xea/0x120 mm/shmem.c:2878 do_fcntl+0x5c8/0xd20 fs/fcntl.c:421 SYSC_fcntl fs/fcntl.c:463 [inline] SyS_fcntl+0xc6/0x100 fs/fcntl.c:448 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x45a219 RSP: 002b:00007f2bd0d65c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000048 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a219 RDX: 0000000000000009 RSI: 0000000000000409 RDI: 0000000000000006 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f2bd0d666d4 R13: 00000000004c0c3d R14: 00000000004d3820 R15: 00000000ffffffff EXT4-fs (loop1): Can't read superblock on 2nd try EXT4-fs (loop1): Can't read superblock on 2nd try EXT4-fs (loop4): ext4_check_descriptors: Inode table for group 0 overlaps superblock EXT4-fs error (device loop4): ext4_iget:4997: inode #2: comm syz-executor.4: bogus i_mode (0) EXT4-fs (loop4): get root inode failed EXT4-fs (loop1): ext4_check_descriptors: Inode table for group 0 overlaps superblock EXT4-fs (loop4): mount failed EXT4-fs (loop1): mounted filesystem without journal. Opts: ,errors=continue netlink: 3 bytes leftover after parsing attributes in process `syz-executor.3'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor.3'. audit: type=1326 audit(2000000435.336:21963): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 pid=30577 comm="syz-executor.4" exe="/root/syz-executor.4" sig=31 arch=c000003e syscall=228 compat=0 ip=0x45d05a code=0x0 FAT-fs (loop1): Unrecognized mount option "0xffffffffffffffff" or missing value audit: type=1326 audit(2000000436.146:21964): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 pid=30577 comm="syz-executor.4" exe="/root/syz-executor.4" sig=31 arch=c000003e syscall=228 compat=0 ip=0x45d05a code=0x0 EXT4-fs (loop5): feature flags set on rev 0 fs, running e2fsck is recommended EXT4-fs (loop5): bad geometry: block count 580964351930795064 exceeds size of device (66048 blocks)