=============================
WARNING: suspicious RCU usage
6.2.0-rc6-syzkaller-17549-gca72d58361ee #0 Not tainted
-----------------------------
lib/maple_tree.c:851 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.3/9608:
 #0: ffff000101b1dae8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x12c/0x154 fs/file.c:1046
 #1: ffff0000c43e5460 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x180/0x46c fs/read_write.c:580
 #2: ffff00010fd3e488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x12c/0x294 fs/kernfs/file.c:325
 #3: ffff0000c03954a0 (kn->active#54){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x134/0x294 fs/kernfs/file.c:326
 #4: ffff80000d6bc9e8 (ksm_thread_mutex){+.+.}-{3:3}, at: run_store+0x88/0x23c mm/ksm.c:2951
 #5: ffff0000c0e4cb88 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_lock include/linux/mmap_lock.h:117 [inline]
 #5: ffff0000c0e4cb88 (&mm->mmap_lock){++++}-{3:3}, at: unmerge_and_remove_all_rmap_items+0xcc/0x5e8 mm/ksm.c:990

stack backtrace:
CPU: 1 PID: 9608 Comm: syz-executor.3 Not tainted 6.2.0-rc6-syzkaller-17549-gca72d58361ee #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/21/2023
Call trace:
 dump_backtrace+0x1c4/0x1f0 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+0x138/0x154 kernel/locking/lockdep.c:6597
 mas_root lib/maple_tree.c:851 [inline]
 mas_start lib/maple_tree.c:1356 [inline]
 mas_state_walk lib/maple_tree.c:3837 [inline]
 mas_walk+0x1c8/0x2a4 lib/maple_tree.c:5046
 mas_find+0x10c/0x13c lib/maple_tree.c:6012
 vma_find include/linux/mm.h:668 [inline]
 vma_next include/linux/mm.h:677 [inline]
 unmerge_and_remove_all_rmap_items+0xdc/0x5e8 mm/ksm.c:991
 run_store+0x18c/0x23c mm/ksm.c:2957
 kobj_attr_store+0x4c/0x70 lib/kobject.c:824
 sysfs_kf_write+0xf4/0x11c fs/sysfs/file.c:136
 kernfs_fop_write_iter+0x1e4/0x294 fs/kernfs/file.c:334
 call_write_iter include/linux/fs.h:2189 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x2dc/0x46c fs/read_write.c:584
 ksys_write+0xb4/0x160 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+0x24/0x34 fs/read_write.c:646
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall arch/arm64/kernel/syscall.c:52 [inline]
 el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x48/0x104 arch/arm64/kernel/syscall.c:193
 el0_svc+0x58/0x150 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