============================= WARNING: suspicious RCU usage 6.3.0-rc1-syzkaller-gfe15c26ee26e #0 Not tainted ----------------------------- lib/maple_tree.c:856 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 6 locks held by syz-executor.0/12018: #0: ffff0000d4953768 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xd8/0x104 fs/file.c:1046 #1: ffff0000d9132460 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x244/0x914 fs/read_write.c:580 #2: ffff0000d221a088 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1c8/0x48c fs/kernfs/file.c:325 #3: ffff0000c114b830 (kn->active#58){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x1e4/0x48c fs/kernfs/file.c:326 #4: ffff800015f912c8 (ksm_thread_mutex){+.+.}-{3:3}, at: run_store+0x10c/0xa1c mm/ksm.c:2953 #5: ffff0000c86e0188 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_lock include/linux/mmap_lock.h:117 [inline] #5: ffff0000c86e0188 (&mm->mmap_lock){++++}-{3:3}, at: unmerge_and_remove_all_rmap_items mm/ksm.c:990 [inline] #5: ffff0000c86e0188 (&mm->mmap_lock){++++}-{3:3}, at: run_store+0x274/0xa1c mm/ksm.c:2959 stack backtrace: CPU: 1 PID: 12018 Comm: syz-executor.0 Not tainted 6.3.0-rc1-syzkaller-gfe15c26ee26e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023 Call trace: dump_backtrace+0x1c8/0x1f4 arch/arm64/kernel/stacktrace.c:158 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd0/0x124 lib/dump_stack.c:106 dump_stack+0x1c/0x28 lib/dump_stack.c:113 lockdep_rcu_suspicious+0x260/0x464 kernel/locking/lockdep.c:6599 mas_root lib/maple_tree.c:856 [inline] mas_start+0x278/0x3c8 lib/maple_tree.c:1357 mas_state_walk lib/maple_tree.c:3838 [inline] mas_walk+0x4c/0x1a4 lib/maple_tree.c:5052 mas_find+0x1e4/0x228 lib/maple_tree.c:6030 vma_next include/linux/mm.h:745 [inline] unmerge_and_remove_all_rmap_items mm/ksm.c:991 [inline] run_store+0x28c/0xa1c mm/ksm.c:2959 kobj_attr_store+0x6c/0x90 lib/kobject.c:832 sysfs_kf_write+0x200/0x280 fs/sysfs/file.c:136 kernfs_fop_write_iter+0x334/0x48c fs/kernfs/file.c:334 call_write_iter include/linux/fs.h:1851 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x610/0x914 fs/read_write.c:584 ksys_write+0x15c/0x26c fs/read_write.c:637 __do_sys_write fs/read_write.c:649 [inline] __se_sys_write fs/read_write.c:646 [inline] __arm64_sys_write+0x7c/0x90 fs/read_write.c:646 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x64/0x198 arch/arm64/kernel/syscall.c:193 el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:591