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KMSAN: uninit-value in bch2_copygc

Status: upstream: reported C repro on 2024/11/09 02:42
Subsystems: bcachefs
[Documentation on labels]
Reported-by: syzbot+8689d10f1894eedf774d@syzkaller.appspotmail.com
First crash: 12d, last: 4d21h
▶ ▼ Discussions (2)
Title Replies (including bot) Last reply
[syzbot] [bcachefs?] KMSAN: uninit-value in bch2_copygc 4 (14) 2024/11/14 21:56
[PATCH] bcachefs: zero-init move_bucket struct in bch2_copygc_get_buckets() 3 (3) 2024/11/12 15:08
▶ ▼ Last patch testing requests (9)
Created Duration User Patch Repo Result
2024/11/14 21:56 29m gianf.trad@gmail.com patch upstream OK log
2024/11/11 23:24 53m gianf.trad@gmail.com patch upstream OK log
2024/11/11 14:26 21m surajsonawane0215@gmail.com patch upstream report log
2024/11/11 14:01 31m gianf.trad@gmail.com patch upstream OK log
2024/11/11 00:31 21m gianf.trad@gmail.com patch upstream report log
2024/11/10 10:07 21m surajsonawane0215@gmail.com patch upstream report log
2024/11/10 05:47 29m surajsonawane0215@gmail.com patch upstream report log
2024/11/09 14:31 23m surajsonawane0215@gmail.com patch upstream error
2024/11/09 11:39 33m surajsonawane0215@gmail.com patch upstream report log

Sample crash report:
=====================================================
BUG: KMSAN: uninit-value in rht_ptr_rcu include/linux/rhashtable.h:376 [inline]
BUG: KMSAN: uninit-value in __rhashtable_lookup include/linux/rhashtable.h:607 [inline]
BUG: KMSAN: uninit-value in rhashtable_lookup include/linux/rhashtable.h:646 [inline]
BUG: KMSAN: uninit-value in rhashtable_lookup_fast include/linux/rhashtable.h:672 [inline]
BUG: KMSAN: uninit-value in bucket_in_flight fs/bcachefs/movinggc.c:144 [inline]
BUG: KMSAN: uninit-value in bch2_copygc_get_buckets fs/bcachefs/movinggc.c:170 [inline]
BUG: KMSAN: uninit-value in bch2_copygc+0x1d3f/0x58f0 fs/bcachefs/movinggc.c:221
 rht_ptr_rcu include/linux/rhashtable.h:376 [inline]
 __rhashtable_lookup include/linux/rhashtable.h:607 [inline]
 rhashtable_lookup include/linux/rhashtable.h:646 [inline]
 rhashtable_lookup_fast include/linux/rhashtable.h:672 [inline]
 bucket_in_flight fs/bcachefs/movinggc.c:144 [inline]
 bch2_copygc_get_buckets fs/bcachefs/movinggc.c:170 [inline]
 bch2_copygc+0x1d3f/0x58f0 fs/bcachefs/movinggc.c:221
 bch2_copygc_thread+0x7f7/0xfa0 fs/bcachefs/movinggc.c:381
 kthread+0x3e2/0x540 kernel/kthread.c:389
 ret_from_fork+0x6d/0x90 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Local variable b205.i created at:
 bch2_copygc_get_buckets fs/bcachefs/movinggc.c:170 [inline]
 bch2_copygc+0x15b3/0x58f0 fs/bcachefs/movinggc.c:221
 bch2_copygc_thread+0x7f7/0xfa0 fs/bcachefs/movinggc.c:381

CPU: 0 UID: 0 PID: 5796 Comm: bch-copygc/loop Not tainted 6.12.0-rc6-syzkaller-00077-g2e1b3cc9d7f7 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
=====================================================
Kernel panic - not syncing: kmsan.panic set ...
CPU: 0 UID: 0 PID: 5796 Comm: bch-copygc/loop Tainted: G    B              6.12.0-rc6-syzkaller-00077-g2e1b3cc9d7f7 #0
Tainted: [B]=BAD_PAGE
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x216/0x2d0 lib/dump_stack.c:120
 dump_stack+0x1e/0x30 lib/dump_stack.c:129
 panic+0x4e2/0xcf0 kernel/panic.c:354
 kmsan_report+0x2c7/0x2d0 mm/kmsan/report.c:218
 __msan_warning+0x95/0x120 mm/kmsan/instrumentation.c:318
 rht_ptr_rcu include/linux/rhashtable.h:376 [inline]
 __rhashtable_lookup include/linux/rhashtable.h:607 [inline]
 rhashtable_lookup include/linux/rhashtable.h:646 [inline]
 rhashtable_lookup_fast include/linux/rhashtable.h:672 [inline]
 bucket_in_flight fs/bcachefs/movinggc.c:144 [inline]
 bch2_copygc_get_buckets fs/bcachefs/movinggc.c:170 [inline]
 bch2_copygc+0x1d3f/0x58f0 fs/bcachefs/movinggc.c:221
 bch2_copygc_thread+0x7f7/0xfa0 fs/bcachefs/movinggc.c:381
 kthread+0x3e2/0x540 kernel/kthread.c:389
 ret_from_fork+0x6d/0x90 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Kernel Offset: disabled
Rebooting in 86400 seconds..

Crashes (8):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/11/05 17:26 upstream 2e1b3cc9d7f7 509da429 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bch2_copygc
2024/11/05 13:47 upstream 2e1b3cc9d7f7 509da429 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bch2_copygc
2024/11/13 04:26 upstream 3022e9d00ebe 62026c85 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bch2_copygc
2024/11/11 01:26 upstream a9cda7c0ffed 6b856513 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bch2_copygc
2024/11/10 10:42 upstream de2f378f2b77 6b856513 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bch2_copygc
2024/11/09 19:13 upstream da4373fbcf00 6b856513 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bch2_copygc
2024/11/09 19:12 upstream da4373fbcf00 6b856513 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bch2_copygc
2024/11/05 02:33 upstream 59b723cd2adb 509da429 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in bch2_copygc
* Struck through repros no longer work on HEAD.