syzbot


WARNING: suspicious RCU usage in mas_walk (2)

Status: auto-obsoleted due to no activity on 2023/10/05 22:43
Subsystems: mm
[Documentation on labels]
Reported-by: syzbot+8645fe63c4d22c8d27b8@syzkaller.appspotmail.com
First crash: 324d, last: 298d
Cause bisection: introduced by (bisect log) :
commit a52f58b34afe095ebc5823684eb264404dad6f7b
Author: Matthew Wilcox (Oracle) <willy@infradead.org>
Date: Mon Jul 24 18:54:10 2023 +0000

  mm: handle faults that merely update the accessed bit under the VMA lock

Crash: WARNING: suspicious RCU usage in mas_walk (log)
Repro: C syz .config
  
Discussions (2)
Title Replies (including bot) Last reply
[syzbot] Monthly mm report (Aug 2023) 0 (1) 2023/08/11 07:44
[syzbot] [mm?] WARNING: suspicious RCU usage in mas_walk (2) 15 (20) 2023/07/27 20:08
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING: suspicious RCU usage in mas_walk (3) mm C done 12 209d 223d 1/26 upstream: reported C repro on 2023/10/10 18:40
upstream WARNING: suspicious RCU usage in mas_walk kernfs C error 234 423d 753d 22/26 fixed on 2023/06/08 14:41
Last patch testing requests (2)
Created Duration User Patch Repo Result
2023/08/24 04:12 21m retest repro linux-next OK log
2023/07/27 18:56 20m willy@infradead.org patch git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next next-20230727 OK log

Sample crash report:
=============================
WARNING: suspicious RCU usage
6.5.0-rc3-next-20230725-syzkaller #0 Not tainted
-----------------------------
lib/maple_tree.c:839 suspicious rcu_dereference_check() usage!

other info that might help us debug this:


rcu_scheduler_active = 2, debug_locks = 1
1 lock held by syz-executor244/5034:
 #0: ffff88802b3f0148 (&vma->vm_lock->lock){++++}-{3:3}, at: vma_start_read include/linux/mm.h:654 [inline]
 #0: ffff88802b3f0148 (&vma->vm_lock->lock){++++}-{3:3}, at: lock_vma_under_rcu+0x201/0x950 mm/memory.c:5585

stack backtrace:
CPU: 0 PID: 5034 Comm: syz-executor244 Not tainted 6.5.0-rc3-next-20230725-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x125/0x1b0 lib/dump_stack.c:106
 lockdep_rcu_suspicious+0x20c/0x3b0 kernel/locking/lockdep.c:6719
 mas_root lib/maple_tree.c:839 [inline]
 mas_root lib/maple_tree.c:837 [inline]
 mas_start lib/maple_tree.c:1381 [inline]
 mas_state_walk lib/maple_tree.c:3832 [inline]
 mas_walk+0x55e/0x7d0 lib/maple_tree.c:4973
 find_mergeable_anon_vma+0x102/0x890 mm/mmap.c:1085
 __anon_vma_prepare+0x7d/0x550 mm/rmap.c:200
 anon_vma_prepare include/linux/rmap.h:159 [inline]
 wp_page_copy mm/memory.c:3202 [inline]
 do_wp_page+0x1bbf/0x2e10 mm/memory.c:3579
 handle_pte_fault mm/memory.c:5133 [inline]
 __handle_mm_fault+0x1704/0x4030 mm/memory.c:5257
 handle_mm_fault+0x47a/0xa00 mm/memory.c:5422
 do_user_addr_fault+0x2e7/0xfe0 arch/x86/mm/fault.c:1342
 handle_page_fault arch/x86/mm/fault.c:1483 [inline]
 exc_page_fault+0x5c/0xd0 arch/x86/mm/fault.c:1539
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:570
RIP: 0033:0x7fbc6b3fd6e5
Code: 6a 00 41 b8 12 10 01 00 be 00 00 00 20 4c 8b 0d 21 9a 0a 00 bf 09 00 00 00 e8 37 2a 03 00 b9 00 04 00 20 ba 46 ae 20 40 31 c0 <c7> 04 25 00 04 00 20 00 00 00 00 be ff ff ff ff bf 10 00 00 00 c7
RSP: 002b:00007ffd68c881f0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 00007ffd68c883c8 RCX: 0000000020000400
RDX: 000000004020ae46 RSI: 0000000000400000 RDI: 0000000020000000
RBP: 00007fbc6b4a3610 R08: 0000000000000003 R09: 0000000000000000
R10: 0000000000011012 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffd68c883b8 R14: 0000000000000001 R15: 0000000000000001
 </TASK>

=============================
WARNING: suspicious RCU usage
6.5.0-rc3-next-20230725-syzkaller #0 Not tainted
-----------------------------
lib/maple_tree.c:795 suspicious rcu_dereference_check() usage!

other info that might help us debug this:


rcu_scheduler_active = 2, debug_locks = 1
1 lock held by syz-executor244/5034:
 #0: ffff88802b3f0148 (&vma->vm_lock->lock){++++}-{3:3}, at: vma_start_read include/linux/mm.h:654 [inline]
 #0: ffff88802b3f0148 (&vma->vm_lock->lock){++++}-{3:3}, at: lock_vma_under_rcu+0x201/0x950 mm/memory.c:5585

stack backtrace:
CPU: 0 PID: 5034 Comm: syz-executor244 Not tainted 6.5.0-rc3-next-20230725-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x125/0x1b0 lib/dump_stack.c:106
 lockdep_rcu_suspicious+0x20c/0x3b0 kernel/locking/lockdep.c:6719
 mt_slot lib/maple_tree.c:795 [inline]
 mt_slot lib/maple_tree.c:792 [inline]
 mtree_range_walk+0x6c5/0x9b0 lib/maple_tree.c:2946
 mas_state_walk lib/maple_tree.c:3839 [inline]
 mas_walk+0x389/0x7d0 lib/maple_tree.c:4973
 find_mergeable_anon_vma+0x102/0x890 mm/mmap.c:1085
 __anon_vma_prepare+0x7d/0x550 mm/rmap.c:200
 anon_vma_prepare include/linux/rmap.h:159 [inline]
 wp_page_copy mm/memory.c:3202 [inline]
 do_wp_page+0x1bbf/0x2e10 mm/memory.c:3579
 handle_pte_fault mm/memory.c:5133 [inline]
 __handle_mm_fault+0x1704/0x4030 mm/memory.c:5257
 handle_mm_fault+0x47a/0xa00 mm/memory.c:5422
 do_user_addr_fault+0x2e7/0xfe0 arch/x86/mm/fault.c:1342
 handle_page_fault arch/x86/mm/fault.c:1483 [inline]
 exc_page_fault+0x5c/0xd0 arch/x86/mm/fault.c:1539
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:570
RIP: 0033:0x7fbc6b3fd6e5
Code: 6a 00 41 b8 12 10 01 00 be 00 00 00 20 4c 8b 0d 21 9a 0a 00 bf 09 00 00 00 e8 37 2a 03 00 b9 00 04 00 20 ba 46 ae 20 40 31 c0 <c7> 04 25 00 04 00 20 00 00 00 00 be ff ff ff ff bf 10 00 00 00 c7
RSP: 002b:00007ffd68c881f0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 00007ffd68c883c8 RCX: 0000000020000400
RDX: 000000004020ae46 RSI: 0000000000400000 RDI: 0000000020000000
RBP: 00007fbc6b4a3610 R08: 0000000000000003 R09: 0000000000000000
R10: 000000000001101

Crashes (97):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/07/25 20:27 linux-next 1e25dd777248 6756545c .config strace log report syz C [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in mas_walk
2023/07/03 22:42 upstream a901a3568fd2 6e553898 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING: suspicious RCU usage in mas_walk
2023/07/03 16:44 upstream a901a3568fd2 6e553898 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING: suspicious RCU usage in mas_walk
2023/07/02 23:29 upstream 995b406c7e97 bfc47836 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING: suspicious RCU usage in mas_walk
2023/07/02 03:05 upstream f8566aa4f176 bfc47836 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING: suspicious RCU usage in mas_walk
2023/07/27 22:43 linux-next 451cc82bd11e 92476829 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in mas_walk
2023/07/27 21:15 linux-next 451cc82bd11e 92476829 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in mas_walk
2023/07/27 18:08 linux-next 451cc82bd11e 92476829 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in mas_walk
2023/07/27 16:35 linux-next 451cc82bd11e 92476829 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in mas_walk
2023/07/27 15:28 linux-next 451cc82bd11e 92476829 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in mas_walk
2023/07/27 13:59 linux-next 451cc82bd11e 92476829 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in mas_walk
2023/07/27 10:37 linux-next 451cc82bd11e 41fe1bae .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in mas_walk
2023/07/27 10:12 linux-next 451cc82bd11e 41fe1bae .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in mas_walk
2023/07/27 08:36 linux-next 451cc82bd11e 41fe1bae .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in mas_walk
2023/07/27 07:34 linux-next 451cc82bd11e 41fe1bae .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in mas_walk
2023/07/27 06:30 linux-next 451cc82bd11e 41fe1bae .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in mas_walk
2023/07/27 04:12 linux-next 0ba5d0720577 41fe1bae .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in mas_walk
2023/07/26 23:45 linux-next 0ba5d0720577 41fe1bae .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in mas_walk
2023/07/26 18:39 linux-next 0ba5d0720577 41fe1bae .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in mas_walk
2023/07/26 18:01 linux-next 0ba5d0720577 41fe1bae .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in mas_walk
2023/07/26 16:45 linux-next 0ba5d0720577 41fe1bae .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in mas_walk
2023/07/26 14:47 linux-next 0ba5d0720577 6756545c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in mas_walk
2023/07/26 13:12 linux-next 0ba5d0720577 6756545c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in mas_walk
2023/07/26 09:45 linux-next 0ba5d0720577 6756545c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in mas_walk
2023/07/26 09:40 linux-next 0ba5d0720577 6756545c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in mas_walk
2023/07/26 09:11 linux-next 0ba5d0720577 6756545c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in mas_walk
2023/07/26 08:52 linux-next 0ba5d0720577 6756545c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in mas_walk
2023/07/26 08:13 linux-next 0ba5d0720577 6756545c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in mas_walk
2023/07/26 04:26 linux-next 1e25dd777248 6756545c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in mas_walk
2023/07/26 02:32 linux-next 1e25dd777248 6756545c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in mas_walk
2023/07/25 19:52 linux-next 1e25dd777248 6756545c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in mas_walk
2023/07/25 18:40 linux-next 1e25dd777248 6756545c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in mas_walk
2023/07/25 18:39 linux-next 1e25dd777248 6756545c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in mas_walk
2023/07/25 18:33 linux-next 1e25dd777248 6756545c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in mas_walk
2023/07/25 18:21 linux-next 1e25dd777248 6756545c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in mas_walk
2023/07/25 18:10 linux-next 1e25dd777248 6756545c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in mas_walk
2023/07/25 17:42 linux-next 1e25dd777248 6756545c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in mas_walk
2023/07/25 17:32 linux-next 1e25dd777248 6756545c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in mas_walk
2023/07/25 16:13 linux-next 1e25dd777248 6756545c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in mas_walk
2023/07/25 15:38 linux-next 1e25dd777248 6756545c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in mas_walk
2023/07/25 13:31 linux-next 1e25dd777248 e88c086e .config console log report info ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in mas_walk
2023/07/25 13:27 linux-next 1e25dd777248 e88c086e .config console log report info ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in mas_walk
2023/07/25 10:12 linux-next 1e25dd777248 9a0ddda3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in mas_walk
2023/07/25 09:06 linux-next 1e25dd777248 9a0ddda3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in mas_walk
2023/07/25 09:04 linux-next 1e25dd777248 9a0ddda3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in mas_walk
2023/07/25 09:02 linux-next 1e25dd777248 9a0ddda3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in mas_walk
2023/07/25 08:39 linux-next 1e25dd777248 9a0ddda3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in mas_walk
2023/07/25 08:22 linux-next 1e25dd777248 9a0ddda3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in mas_walk
2023/07/25 08:13 linux-next 1e25dd777248 9a0ddda3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in mas_walk
2023/07/25 07:56 linux-next 1e25dd777248 9a0ddda3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in mas_walk
2023/07/25 07:50 linux-next 1e25dd777248 9a0ddda3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in mas_walk
2023/07/25 06:32 linux-next 1e25dd777248 9a0ddda3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in mas_walk
2023/07/25 06:22 linux-next 1e25dd777248 9a0ddda3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in mas_walk
* Struck through repros no longer work on HEAD.