syzbot


KCSAN: data-race in mas_state_walk / mas_wr_store_entry

Status: moderation: reported on 2025/04/27 04:37
Subsystems: mm
[Documentation on labels]
Reported-by: syzbot+ff9c72a9eb3dc1c87021@syzkaller.appspotmail.com
First crash: 260d, last: 7d12h

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

write to 0xffff88810465aa08 of 8 bytes by task 15203 on cpu 1:
 mas_wr_slot_store lib/maple_tree.c:3585 [inline]
 mas_wr_store_entry+0x11e9/0x2750 lib/maple_tree.c:3761
 mas_store_prealloc+0x760/0xa90 lib/maple_tree.c:5169
 vma_iter_store_overwrite mm/vma.h:541 [inline]
 commit_merge+0x6a5/0x730 mm/vma.c:758
 vma_expand+0x1fe/0x460 mm/vma.c:1160
 vma_merge_new_range+0x296/0x310 mm/vma.c:1092
 __mmap_region mm/vma.c:2703 [inline]
 mmap_region+0xa71/0x1410 mm/vma.c:2786
 do_mmap+0x9b3/0xbe0 mm/mmap.c:558
 vm_mmap_pgoff+0x17a/0x2e0 mm/util.c:581
 ksys_mmap_pgoff+0xc2/0x310 mm/mmap.c:604
 x64_sys_call+0x16bb/0x3000 arch/x86/include/generated/asm/syscalls_64.h:10
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xca/0x2b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff88810465aa08 of 8 bytes by task 15205 on cpu 0:
 mtree_range_walk lib/maple_tree.c:2561 [inline]
 mas_state_walk+0x28f/0x650 lib/maple_tree.c:3298
 mas_walk+0x60/0x150 lib/maple_tree.c:4599
 lock_vma_under_rcu+0x95/0x1b0 mm/mmap_lock.c:253
 do_user_addr_fault+0x233/0x1080 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:618

value changed: 0x00007fcd4e2b5fff -> 0x00007fcd4e294fff

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 15205 Comm: syz.0.3908 Tainted: G        W           syzkaller #0 PREEMPT(voluntary) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
==================================================================

Crashes (105):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/01/05 03:08 upstream 54e82e93ca93 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_state_walk / mas_wr_store_entry
2026/01/03 10:40 upstream 805f9a061372 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_state_walk / mas_wr_store_entry
2025/12/29 18:26 upstream 7839932417dd d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_state_walk / mas_wr_store_entry
2025/12/29 04:02 upstream c875a6c32467 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_state_walk / mas_wr_store_entry
2025/12/27 03:47 upstream 3f0e9c8cefa9 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_state_walk / mas_wr_store_entry
2025/12/16 12:33 upstream 40fbbd64bba6 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_state_walk / mas_wr_store_entry
2025/12/13 02:04 upstream 187d0801404f d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_state_walk / mas_wr_store_entry
2025/12/09 02:52 upstream c2f2b01b74be d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_state_walk / mas_wr_store_entry
2025/12/06 12:43 upstream 416f99c3b16f d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_state_walk / mas_wr_store_entry
2025/12/05 23:18 upstream d1d36025a617 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_state_walk / mas_wr_store_entry
2025/12/03 05:12 upstream d61f1cc5db79 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_state_walk / mas_wr_store_entry
2025/12/02 08:57 upstream 1d18101a644e d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_state_walk / mas_wr_store_entry
2025/12/01 13:09 upstream 7d0a66e4bb90 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_state_walk / mas_wr_store_entry
2025/11/30 22:25 upstream e69c7c175115 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_state_walk / mas_wr_store_entry
2025/11/30 02:42 upstream 6bda50f4333f d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_state_walk / mas_wr_store_entry
2025/11/28 16:44 upstream e538109ac71d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_state_walk / mas_wr_store_entry
2025/11/27 19:26 upstream 765e56e41a5a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_state_walk / mas_wr_store_entry
2025/11/24 15:08 upstream ac3fd01e4c1e bf6fe8fe .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_state_walk / mas_wr_store_entry
2025/11/24 03:33 upstream d0e88704d96c 4fb8ef37 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_state_walk / mas_wr_store_entry
2025/11/22 04:47 upstream 2eba5e05d9bc 4fb8ef37 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_state_walk / mas_wr_store_entry
2025/11/20 04:10 upstream 23cb64fb7625 26ee5237 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_state_walk / mas_wr_store_entry
2025/11/18 23:02 upstream 5bebe8de1926 ef766cd7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_state_walk / mas_wr_store_entry
2025/11/13 13:51 upstream e927c520e1ba 07e030de .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_state_walk / mas_wr_store_entry
2025/11/11 13:35 upstream 4427259cc7f7 4e1406b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_state_walk / mas_wr_store_entry
2025/11/08 15:31 upstream e811c33b1f13 4e1406b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_state_walk / mas_wr_store_entry
2025/11/05 12:29 upstream 17d85f33a83b a6c9c731 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_state_walk / mas_wr_store_entry
2025/11/01 21:16 upstream 691d401c7e0e 2c50b6a9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_state_walk / mas_wr_store_entry
2025/10/31 08:04 upstream d127176862a9 2c50b6a9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_state_walk / mas_wr_store_entry
2025/10/29 17:09 upstream e53642b87a4f fd2207e7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_state_walk / mas_wr_store_entry
2025/10/24 16:38 upstream 6fab32bb6508 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_state_walk / mas_wr_store_entry
2025/10/24 01:01 upstream 266ee584e55e c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_state_walk / mas_wr_store_entry
2025/10/22 20:39 upstream dd72c8fcf6d3 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_state_walk / mas_wr_store_entry
2025/10/19 20:51 upstream d9043c79ba68 1c8c8cd8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_state_walk / mas_wr_store_entry
2025/10/19 08:11 upstream 1c64efcb083c 1c8c8cd8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_state_walk / mas_wr_store_entry
2025/10/17 09:06 upstream 98ac9cc4b445 19568248 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_state_walk / mas_wr_store_entry
2025/10/16 08:32 upstream 7ea30958b305 19568248 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_state_walk / mas_wr_store_entry
2025/10/11 20:20 upstream 0739473694c4 ff1712fe .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_state_walk / mas_wr_store_entry
2025/10/09 16:20 upstream ec714e371f22 7e2882b3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_state_walk / mas_wr_store_entry
2025/10/09 11:52 upstream cd5a0afbdf80 7e2882b3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_state_walk / mas_wr_store_entry
2025/10/01 04:09 upstream 30d4efb2f5a5 65a0eece .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_state_walk / mas_wr_store_entry
2025/09/29 22:23 upstream e5f0a698b34e 86341da6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_state_walk / mas_wr_store_entry
2025/09/27 01:09 upstream 083fc6d7fa0d 001c9061 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_state_walk / mas_wr_store_entry
2025/09/24 11:09 upstream cec1e6e5d1ab 0abd0691 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_state_walk / mas_wr_store_entry
2025/09/14 16:51 upstream f83a4f2a4d8c e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_state_walk / mas_wr_store_entry
2025/09/11 23:42 upstream 02ffd6f89c50 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_state_walk / mas_wr_store_entry
2025/09/08 17:36 upstream 76eeb9b8de98 d291dd2d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_state_walk / mas_wr_store_entry
2025/04/27 04:36 upstream 5bc1018675ec c6b4fb39 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in mas_state_walk / mas_wr_store_entry
* Struck through repros no longer work on HEAD.