syzbot


KCSAN: data-race in mas_wmb_replace / mtree_range_walk (2)

Status: moderation: reported on 2026/04/16 07:19
Subsystems: mm
Labels: prio:low
[Documentation on labels]
Reported-by: syzbot+7265211618d78be5c8e2@syzkaller.appspotmail.com
First crash: 66d, last: 15h00m
✨ AI Jobs (2)
ID Workflow Result Correct Bug Created Started Finished Revision Error
2ef9e8fe-d94f-4e89-8234-d1b376088fcb assessment-security DenialOfService: ❌ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ✅ UserNamespace: ✅ VMGuestTrigger: ❌ VMHostTrigger: ❌ KCSAN: data-race in mas_wmb_replace / mtree_range_walk (2) 2026/05/25 22:38 2026/05/25 22:38 2026/05/25 23:31 c69befb30ac10e158cc9d1557b508ee3f0eca1de

			
		
ed78a0ab-39ee-4c22-ac93-e5909490249b assessment-kcsan Benign: ✅ Confident: ✅ KCSAN: data-race in mas_wmb_replace / mtree_range_walk (2) 2026/04/16 07:18 2026/04/16 07:18 2026/04/16 07:41 df15c5f3d9deb74ba8dc519449837e23f3040ac6

			
		
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in mas_wmb_replace / mtree_range_walk mm 6 566 423d 893d 0/29 auto-obsoleted due to no activity on 2025/06/12 01:09

Sample crash report:
==================================================================
BUG: KCSAN: data-race in mas_wmb_replace / mtree_range_walk

write to 0xffff88810210c300 of 8 bytes by task 22668 on cpu 1:
 mte_set_node_dead lib/maple_tree.c:299 [inline]
 mas_put_in_tree lib/maple_tree.c:1579 [inline]
 mas_topiary_replace lib/maple_tree.c:1823 [inline]
 mas_wmb_replace+0x22e/0x1770 lib/maple_tree.c:2083
 mas_wr_store_entry+0x54a7/0x5a90 lib/maple_tree.c:-1
 mas_store_prealloc+0x421/0x670 lib/maple_tree.c:4936
 vma_iter_store_overwrite mm/vma.h:616 [inline]
 vma_iter_store_new mm/vma.h:623 [inline]
 __mmap_new_vma mm/vma.c:2583 [inline]
 __mmap_region mm/vma.c:2774 [inline]
 mmap_region+0x1c69/0x20c0 mm/vma.c:2860
 do_mmap+0x970/0xbc0 mm/mmap.c:560
 vm_mmap_pgoff+0x183/0x2d0 mm/util.c:581
 ksys_mmap_pgoff+0xc1/0x310 mm/mmap.c:606
 x64_sys_call+0x14df/0x3020 arch/x86/include/generated/asm/syscalls_64.h:10
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x136/0x3c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff88810210c300 of 8 bytes by task 22670 on cpu 0:
 ma_dead_node lib/maple_tree.c:544 [inline]
 mtree_range_walk+0x35a/0x480 lib/maple_tree.c:2051
 mas_state_walk lib/maple_tree.c:2952 [inline]
 mas_walk+0x1ac/0x340 lib/maple_tree.c:4366
 lock_vma_under_rcu+0xc9/0x210 mm/mmap_lock.c:304
 do_user_addr_fault+0x237/0x1060 arch/x86/mm/fault.c:1334
 handle_page_fault arch/x86/mm/fault.c:1483 [inline]
 exc_page_fault+0x62/0xa0 arch/x86/mm/fault.c:1536
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595

value changed: 0xffff88810931c641 -> 0xffff88810210c300

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 22670 Comm: syz.3.5181 Tainted: G        W           syzkaller #0 PREEMPT(lazy) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
==================================================================

Crashes (48):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/06/20 20:12 upstream 1a3746ccbb0a 43bfcdb0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_wmb_replace / mtree_range_walk
2026/06/19 14:09 upstream 9ecfb2f7287a 570c59ee .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_wmb_replace / mtree_range_walk
2026/06/19 03:47 upstream 83f1454877cc a776b0d0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_wmb_replace / mtree_range_walk
2026/06/17 10:31 upstream 6b5a2b7d9bc1 62cc6db3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_wmb_replace / mtree_range_walk
2026/06/16 19:21 upstream b1cbabe84ca1 a3998659 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_wmb_replace / mtree_range_walk
2026/06/16 02:49 upstream 0e0611827f33 50bb0618 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_wmb_replace / mtree_range_walk
2026/06/15 01:15 upstream 8cd9520d35a6 1d2f3589 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_wmb_replace / mtree_range_walk
2026/06/14 08:28 upstream 2b07ea76fd28 1d2f3589 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_wmb_replace / mtree_range_walk
2026/06/13 12:04 upstream 062871f1371b 1d2f3589 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_wmb_replace / mtree_range_walk
2026/06/12 15:25 upstream 2b414a95b8f7 e93da63e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_wmb_replace / mtree_range_walk
2026/06/11 13:11 upstream 9716c086c8e8 b754d2d8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_wmb_replace / mtree_range_walk
2026/06/10 22:19 upstream acb7500801e9 f79bac11 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_wmb_replace / mtree_range_walk
2026/06/09 06:19 upstream 2d3090a8aeb5 656e94c6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_wmb_replace / mtree_range_walk
2026/06/05 19:25 upstream ddd664bbff63 48b6c3fa .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_wmb_replace / mtree_range_walk
2026/06/04 19:42 upstream ba3e43a9e601 197909be .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_wmb_replace / mtree_range_walk
2026/06/03 22:29 upstream ba3e43a9e601 234057e5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_wmb_replace / mtree_range_walk
2026/06/02 02:47 upstream e43ffb69e043 1095583b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_wmb_replace / mtree_range_walk
2026/06/01 06:21 upstream e43ffb69e043 6b4a8443 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_wmb_replace / mtree_range_walk
2026/05/31 11:19 upstream 9d87d0fc8c8e 6b4a8443 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_wmb_replace / mtree_range_walk
2026/05/29 18:49 upstream 8fde5d1d47f6 6b4a8443 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_wmb_replace / mtree_range_walk
2026/05/27 16:41 upstream eb3f4b7426cf 8777bdc3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_wmb_replace / mtree_range_walk
2026/05/26 14:30 upstream e8c2f9fdadee a3e47276 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_wmb_replace / mtree_range_walk
2026/05/24 19:40 upstream 4cbfe4502e3d c69befb3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_wmb_replace / mtree_range_walk
2026/05/23 22:33 upstream eed108edc117 c69befb3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_wmb_replace / mtree_range_walk
2026/05/20 15:15 upstream 27fa82620cba 62fb93a2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_wmb_replace / mtree_range_walk
2026/05/19 18:21 upstream ab5fce87a778 223544dc .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_wmb_replace / mtree_range_walk
2026/05/18 02:31 upstream e5d505e3664b de5aae85 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_wmb_replace / mtree_range_walk
2026/05/17 05:03 upstream 6916d5703ddf de5aae85 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_wmb_replace / mtree_range_walk
2026/05/16 17:59 upstream d458a240344c a15a64a6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_wmb_replace / mtree_range_walk
2026/05/14 14:43 upstream e1914add2799 6ccb967e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_wmb_replace / mtree_range_walk
2026/05/13 03:44 upstream c21b90f77687 a0949470 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_wmb_replace / mtree_range_walk
2026/05/10 19:34 upstream 1bfaee9d3351 29233ece .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_wmb_replace / mtree_range_walk
2026/05/09 12:08 upstream 27a26ccfd528 29233ece .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_wmb_replace / mtree_range_walk
2026/05/06 10:41 upstream 9207d47f966b 26da2c66 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_wmb_replace / mtree_range_walk
2026/05/05 00:38 upstream c7e4e4d5f7dc a898ba9c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_wmb_replace / mtree_range_walk
2026/05/04 04:41 upstream f377d0025eb0 a0d91488 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_wmb_replace / mtree_range_walk
2026/05/03 07:19 upstream 66edb901bf87 a0d91488 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_wmb_replace / mtree_range_walk
2026/05/01 17:36 upstream 26fd6bff2c05 753c55b9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_wmb_replace / mtree_range_walk
2026/04/26 05:02 upstream 897d54018cc9 9c2d0995 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_wmb_replace / mtree_range_walk
2026/04/25 05:32 upstream 27d128c1cff6 9c2d0995 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_wmb_replace / mtree_range_walk
2026/04/24 21:40 upstream dd6c438c3e64 1c2b9291 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_wmb_replace / mtree_range_walk
2026/04/24 10:01 upstream 45dcf5e28813 9cfb3ca7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_wmb_replace / mtree_range_walk
2026/04/23 14:51 upstream 2e6803928193 4c3406dc .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_wmb_replace / mtree_range_walk
2026/04/22 18:41 upstream 6596a02b2078 4595e353 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_wmb_replace / mtree_range_walk
2026/04/20 01:45 upstream c1f49dea2b8f 303e2802 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_wmb_replace / mtree_range_walk
2026/04/19 05:12 upstream eb5249b12507 303e2802 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_wmb_replace / mtree_range_walk
2026/04/18 09:29 upstream 8541d8f725c6 303e2802 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_wmb_replace / mtree_range_walk
2026/04/16 07:18 upstream aec2f682d47c df15c5f3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_wmb_replace / mtree_range_walk
* Struck through repros no longer work on HEAD.