syzbot


WARNING: suspicious RCU usage in mas_state_walk

Status: closed as invalid on 2023/02/08 16:28
Subsystems: maple-tree
[Documentation on labels]
First crash: 528d, last: 528d
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING: suspicious RCU usage in mas_state_walk (2) kernfs C 18 506d 523d 0/27 auto-obsoleted due to no activity on 2023/06/30 05:34

Sample crash report:
=============================
WARNING: suspicious RCU usage
6.2.0-rc7-syzkaller-17891-geaed33698e35 #0 Not tainted
-----------------------------
lib/maple_tree.c:852 suspicious rcu_dereference_check() usage!

other info that might help us debug this:


rcu_scheduler_active = 2, debug_locks = 1
5 locks held by syz-executor115/5128:
 #0: ffff0000c82f2460 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x174/0x44c
 #1: ffff0000c95dd688 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x120/0x288
 #2: ffff0000c03954a0 (kn->active#42){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x128/0x288
 #3: ffff80000d4bc640 (ksm_thread_mutex){+.+.}-{3:3}, at: run_store+0x8c/0x608
 #4: ffff0000c94cb748 (&mm->mmap_lock){++++}-{3:3}, at: run_store+0x200/0x608

stack backtrace:
CPU: 0 PID: 5128 Comm: syz-executor115 Not tainted 6.2.0-rc7-syzkaller-17891-geaed33698e35 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/21/2023
Call trace:
 dump_backtrace+0x1c8/0x1f4
 show_stack+0x2c/0x3c
 dump_stack_lvl+0xd0/0x124
 dump_stack+0x1c/0x28
 lockdep_rcu_suspicious+0x138/0x154
 mas_state_walk+0x1a4/0x200
 mas_walk+0x2c/0xc4
 mas_find+0x10c/0x13c
 run_store+0x214/0x608
 kobj_attr_store+0x4c/0x70
 sysfs_kf_write+0xf4/0x11c
 kernfs_fop_write_iter+0x1d8/0x288
 vfs_write+0x2bc/0x44c
 ksys_write+0xb4/0x160
 __arm64_sys_write+0x24/0x34
 invoke_syscall+0x64/0x178
 el0_svc_common+0xbc/0x180
 do_el0_svc+0x48/0x110
 el0_svc+0x58/0x14c
 el0t_64_sync_handler+0x84/0xf0
 el0t_64_sync+0x190/0x194

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/02/08 09:36 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci eaed33698e35 15c3d445 .config console log report syz C ci-upstream-gce-arm64 WARNING: suspicious RCU usage in mas_state_walk
2023/02/08 06:09 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci eaed33698e35 15c3d445 .config console log report info ci-upstream-gce-arm64 WARNING: suspicious RCU usage in mas_state_walk
* Struck through repros no longer work on HEAD.