syzbot


KCSAN: data-race in call_rcu / mas_state_walk (2)

Status: moderation: reported on 2025/04/25 11:57
Subsystems: mm
[Documentation on labels]
Reported-by: syzbot+c340ed86ab0dac6ba5a7@syzkaller.appspotmail.com
First crash: 147d, last: 1d01h
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in call_rcu / mas_state_walk mm 6 284 619d 871d 0/29 auto-obsoleted due to no activity on 2024/02/06 14:05

Sample crash report:
==================================================================
BUG: KCSAN: data-race in call_rcu / mas_state_walk

write to 0xffff888122e2fd10 of 8 bytes by task 17524 on cpu 1:
 __call_rcu_common kernel/rcu/tree.c:3121 [inline]
 call_rcu+0x44/0x3f0 kernel/rcu/tree.c:3243
 ma_free_rcu lib/maple_tree.c:211 [inline]
 mas_topiary_node lib/maple_tree.c:2527 [inline]
 mas_topiary_replace lib/maple_tree.c:2628 [inline]
 mas_wmb_replace+0xc6a/0x14a0 lib/maple_tree.c:2651
 mas_split lib/maple_tree.c:3390 [inline]
 mas_commit_b_node lib/maple_tree.c:3410 [inline]
 mas_wr_bnode lib/maple_tree.c:4079 [inline]
 mas_wr_store_entry+0x1773/0x2b50 lib/maple_tree.c:4111
 mas_store_prealloc+0x74d/0x9e0 lib/maple_tree.c:5510
 vma_iter_store_overwrite mm/vma.h:501 [inline]
 vma_iter_store_new+0x1c5/0x200 mm/vma.h:508
 vma_complete+0x125/0x580 mm/vma.c:354
 __split_vma+0x591/0x650 mm/vma.c:568
 split_vma mm/vma.c:598 [inline]
 vma_modify+0x21e/0xc80 mm/vma.c:1623
 vma_modify_flags+0x101/0x130 mm/vma.c:1649
 mprotect_fixup+0x2cc/0x570 mm/mprotect.c:816
 do_mprotect_pkey+0x6d6/0x980 mm/mprotect.c:990
 __do_sys_mprotect mm/mprotect.c:1011 [inline]
 __se_sys_mprotect mm/mprotect.c:1008 [inline]
 __x64_sys_mprotect+0x48/0x60 mm/mprotect.c:1008
 x64_sys_call+0x274e/0x2ff0 arch/x86/include/generated/asm/syscalls_64.h:11
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888122e2fd10 of 8 bytes by task 17526 on cpu 0:
 mtree_range_walk lib/maple_tree.c:2787 [inline]
 mas_state_walk+0x2f5/0x650 lib/maple_tree.c:3636
 mas_walk+0x60/0x150 lib/maple_tree.c:4939
 lock_vma_under_rcu+0x8d/0x160 mm/mmap_lock.c:143
 do_user_addr_fault+0x233/0x1090 arch/x86/mm/fault.c:1327
 handle_page_fault arch/x86/mm/fault.c:1476 [inline]
 exc_page_fault+0x62/0xa0 arch/x86/mm/fault.c:1532
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623

value changed: 0x00007f5e1c16ffff -> 0xffffffff85649c50

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 17526 Comm: syz.2.4988 Tainted: G        W           syzkaller #0 PREEMPT(voluntary) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
==================================================================

Crashes (156):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/09/18 13:19 upstream 8b789f2b7602 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in call_rcu / mas_state_walk
2025/09/18 02:40 upstream d4b779985a6c e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in call_rcu / mas_state_walk
2025/09/17 01:16 upstream 5aca7966d2a7 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in call_rcu / mas_state_walk
2025/09/15 15:25 upstream f83ec76bf285 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in call_rcu / mas_state_walk
2025/09/15 03:05 upstream 79e8447ec662 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in call_rcu / mas_state_walk
2025/09/14 10:47 upstream f83a4f2a4d8c e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in call_rcu / mas_state_walk
2025/09/14 02:55 upstream 5cd64d4f9268 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in call_rcu / mas_state_walk
2025/09/12 10:35 upstream 320475fbd590 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in call_rcu / mas_state_walk
2025/09/10 23:25 upstream 7aac71907bde fdeaa69b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in call_rcu / mas_state_walk
2025/09/10 05:07 upstream 9dd1835ecda5 fdeaa69b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in call_rcu / mas_state_walk
2025/09/08 09:39 upstream 76eeb9b8de98 d291dd2d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in call_rcu / mas_state_walk
2025/09/07 18:46 upstream 6ab41fca2e80 d291dd2d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in call_rcu / mas_state_walk
2025/09/06 13:15 upstream d1d10cea0895 d291dd2d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in call_rcu / mas_state_walk
2025/09/06 01:11 upstream c8ed9b5c02a5 d291dd2d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in call_rcu / mas_state_walk
2025/09/04 21:09 upstream 08b06c30a445 d291dd2d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in call_rcu / mas_state_walk
2025/09/03 23:05 upstream ec299e4dc21e 96a211bc .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in call_rcu / mas_state_walk
2025/09/02 23:11 upstream e6b9dce0aeeb 96a211bc .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in call_rcu / mas_state_walk
2025/09/02 20:51 upstream b320789d6883 96a211bc .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in call_rcu / mas_state_walk
2025/09/01 10:44 upstream b320789d6883 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in call_rcu / mas_state_walk
2025/08/31 21:41 upstream 5c3b3264e585 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in call_rcu / mas_state_walk
2025/08/29 20:24 upstream fb679c832b64 3e1beec6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in call_rcu / mas_state_walk
2025/08/27 20:42 upstream 39f90c196721 e12e5ba4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in call_rcu / mas_state_walk
2025/08/24 18:37 upstream 69fd6b99b8f8 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in call_rcu / mas_state_walk
2025/08/22 09:44 upstream 3957a5720157 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in call_rcu / mas_state_walk
2025/08/21 21:10 upstream 068a56e56fa8 3e79b825 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in call_rcu / mas_state_walk
2025/08/21 00:44 upstream 41cd3fd15263 0b9605c8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in call_rcu / mas_state_walk
2025/08/19 20:54 upstream b19a97d57c15 254a27c1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in call_rcu / mas_state_walk
2025/08/19 02:01 upstream be48bcf004f9 523f460e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in call_rcu / mas_state_walk
2025/08/18 00:49 upstream 8d561baae505 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in call_rcu / mas_state_walk
2025/08/17 12:09 upstream 99bade344cfa 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in call_rcu / mas_state_walk
2025/08/17 01:51 upstream 90d970cade8e 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in call_rcu / mas_state_walk
2025/08/16 08:13 upstream dfd4b508c8c6 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in call_rcu / mas_state_walk
2025/08/15 16:39 upstream ee94b00c1a64 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in call_rcu / mas_state_walk
2025/08/14 17:36 upstream 0cc53520e68b 5d8c2ac2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in call_rcu / mas_state_walk
2025/08/13 23:48 upstream dfc0f6373094 22ec1469 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in call_rcu / mas_state_walk
2025/08/13 09:11 upstream 8742b2d8935f 22ec1469 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in call_rcu / mas_state_walk
2025/08/13 01:03 upstream 0e39a731820a 22ec1469 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in call_rcu / mas_state_walk
2025/08/12 11:40 upstream 53e760d89498 c06e8995 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in call_rcu / mas_state_walk
2025/08/11 00:11 upstream 8f5ae30d69d7 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in call_rcu / mas_state_walk
2025/08/10 11:52 upstream 2b38afce25c4 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in call_rcu / mas_state_walk
2025/08/10 04:00 upstream 561c80369df0 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in call_rcu / mas_state_walk
2025/08/09 11:49 upstream 2988dfed8a5d 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in call_rcu / mas_state_walk
2025/08/08 19:24 upstream 37816488247d 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in call_rcu / mas_state_walk
2025/08/08 07:04 upstream bec077162bd0 6a893178 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in call_rcu / mas_state_walk
2025/08/07 07:26 upstream cca7a0aae895 9a42d6b1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in call_rcu / mas_state_walk
2025/08/06 17:24 upstream 479058002c32 ffe1dd46 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in call_rcu / mas_state_walk
2025/08/06 05:49 upstream 6bcdbd62bd56 ffe1dd46 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in call_rcu / mas_state_walk
2025/04/25 11:56 upstream 02ddfb981de8 e3715315 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in call_rcu / mas_state_walk
* Struck through repros no longer work on HEAD.