KMSAN: uninit-value in btrfs_clean_tree

KMSAN: uninit-value in btrfs_clean_tree_block
Status: upstream: reported on 2020/09/19 08:12
Reported-by: syzbot+37fb1c865f4d57cc1e7c@syzkaller.appspotmail.com
First crash: 41d, last: now

Sample crash report:

=====================================================
BUG: KMSAN: uninit-value in btrfs_clean_tree_block+0x293/0x330 fs/btrfs/disk-io.c:1065
CPU: 0 PID: 9485 Comm: syz-executor.3 Not tainted 5.9.0-rc8-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x21c/0x280 lib/dump_stack.c:118
 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:122
 __msan_warning+0x5f/0xa0 mm/kmsan/kmsan_instr.c:201
 btrfs_clean_tree_block+0x293/0x330 fs/btrfs/disk-io.c:1065
 btrfs_init_new_buffer fs/btrfs/extent-tree.c:4531 [inline]
 btrfs_alloc_tree_block+0x951/0x1f00 fs/btrfs/extent-tree.c:4608
 alloc_tree_block_no_bg_flush fs/btrfs/ctree.c:987 [inline]
 __btrfs_cow_block+0xae9/0x23e0 fs/btrfs/ctree.c:1042
 btrfs_cow_block+0xa22/0xd10 fs/btrfs/ctree.c:1487
 commit_cowonly_roots+0x1c0/0x1620 fs/btrfs/transaction.c:1184
 btrfs_commit_transaction+0x22f2/0x5620 fs/btrfs/transaction.c:2272
 btrfs_commit_super+0x1b7/0x1f0 fs/btrfs/disk-io.c:4020
 close_ctree+0x44a/0xd7f fs/btrfs/disk-io.c:4083
 btrfs_put_super+0x53/0x70 fs/btrfs/super.c:321
 generic_shutdown_super+0x2ab/0x650 fs/super.c:464
 kill_anon_super+0x6c/0xb0 fs/super.c:1108
 btrfs_kill_super+0x61/0x90 fs/btrfs/super.c:2265
 deactivate_locked_super+0x10d/0x1e0 fs/super.c:335
 deactivate_super+0x1b7/0x1d0 fs/super.c:366
 cleanup_mnt+0x796/0x880 fs/namespace.c:1118
 __cleanup_mnt+0x3b/0x50 fs/namespace.c:1125
 task_work_run+0x1f3/0x2c0 kernel/task_work.c:141
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:165 [inline]
 exit_to_user_mode_prepare+0x434/0x540 kernel/entry/common.c:192
 syscall_exit_to_user_mode+0x35/0x50 kernel/entry/common.c:267
 __do_fast_syscall_32+0x151/0x180 arch/x86/entry/common.c:80
 do_fast_syscall_32+0x6a/0xc0 arch/x86/entry/common.c:162
 do_SYSENTER_32+0x73/0x90 arch/x86/entry/common.c:205
 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c
RIP: 0023:0xf7f45549
Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 002b:00000000ffd0420c EFLAGS: 00000296 ORIG_RAX: 0000000000000034
RAX: 0000000000000000 RBX: 00000000ffd0429c RCX: 0000000000000002
RDX: 000000000a637228 RSI: 000000000a6372a4 RDI: 00000000080d8abe
RBP: 00000000ffd0429c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000

Uninit was created at:
 kmsan_save_stack_with_flags+0x3c/0x90 mm/kmsan/kmsan.c:129
 kmsan_alloc_page+0xd3/0x1f0 mm/kmsan/kmsan_shadow.c:278
 __alloc_pages_nodemask+0x84e/0x1040 mm/page_alloc.c:4938
 alloc_pages_current+0x79b/0xb40 mm/mempolicy.c:2275
 alloc_pages include/linux/gfp.h:545 [inline]
 __page_cache_alloc+0xbd/0x2f0 mm/filemap.c:957
 pagecache_get_page+0xe80/0x1cc0 mm/filemap.c:1808
 find_or_create_page include/linux/pagemap.h:348 [inline]
 alloc_extent_buffer+0x790/0x27a0 fs/btrfs/extent_io.c:5246
 btrfs_find_create_tree_block+0x68/0x80 fs/btrfs/disk-io.c:1030
 btrfs_init_new_buffer fs/btrfs/extent-tree.c:4512 [inline]
 btrfs_alloc_tree_block+0x4f6/0x1f00 fs/btrfs/extent-tree.c:4608
 alloc_tree_block_no_bg_flush fs/btrfs/ctree.c:987 [inline]
 __btrfs_cow_block+0xae9/0x23e0 fs/btrfs/ctree.c:1042
 btrfs_cow_block+0xa22/0xd10 fs/btrfs/ctree.c:1487
 commit_cowonly_roots+0x1c0/0x1620 fs/btrfs/transaction.c:1184
 btrfs_commit_transaction+0x22f2/0x5620 fs/btrfs/transaction.c:2272
 btrfs_commit_super+0x1b7/0x1f0 fs/btrfs/disk-io.c:4020
 close_ctree+0x44a/0xd7f fs/btrfs/disk-io.c:4083
 btrfs_put_super+0x53/0x70 fs/btrfs/super.c:321
 generic_shutdown_super+0x2ab/0x650 fs/super.c:464
 kill_anon_super+0x6c/0xb0 fs/super.c:1108
 btrfs_kill_super+0x61/0x90 fs/btrfs/super.c:2265
 deactivate_locked_super+0x10d/0x1e0 fs/super.c:335
 deactivate_super+0x1b7/0x1d0 fs/super.c:366
 cleanup_mnt+0x796/0x880 fs/namespace.c:1118
 __cleanup_mnt+0x3b/0x50 fs/namespace.c:1125
 task_work_run+0x1f3/0x2c0 kernel/task_work.c:141
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:165 [inline]
 exit_to_user_mode_prepare+0x434/0x540 kernel/entry/common.c:192
 syscall_exit_to_user_mode+0x35/0x50 kernel/entry/common.c:267
 __do_fast_syscall_32+0x151/0x180 arch/x86/entry/common.c:80
 do_fast_syscall_32+0x6a/0xc0 arch/x86/entry/common.c:162
 do_SYSENTER_32+0x73/0x90 arch/x86/entry/common.c:205
 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c
=====================================================

Crashes (4384):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	VM info	Maintainers
ci-upstream-kmsan-gce-386	2020/10/26 12:33	https://github.com/google/kmsan.git master	e1617422	a7aac492	.config	log	report	info	clm@fb.com, dsterba@suse.com, josef@toxicpanda.com, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org
ci-upstream-kmsan-gce-386	2020/10/26 12:23	https://github.com/google/kmsan.git master	e1617422	a7aac492	.config	log	report	info	clm@fb.com, dsterba@suse.com, josef@toxicpanda.com, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org
ci-upstream-kmsan-gce-386	2020/10/26 11:19	https://github.com/google/kmsan.git master	e1617422	a7aac492	.config	log	report	info	clm@fb.com, dsterba@suse.com, josef@toxicpanda.com, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org
ci-upstream-kmsan-gce-386	2020/10/26 10:18	https://github.com/google/kmsan.git master	e1617422	a7aac492	.config	log	report	info	clm@fb.com, dsterba@suse.com, josef@toxicpanda.com, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org
ci-upstream-kmsan-gce-386	2020/10/26 09:55	https://github.com/google/kmsan.git master	e1617422	a7aac492	.config	log	report	info	clm@fb.com, dsterba@suse.com, josef@toxicpanda.com, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org
ci-upstream-kmsan-gce-386	2020/10/26 08:54	https://github.com/google/kmsan.git master	e1617422	a1839e81	.config	log	report	info	clm@fb.com, dsterba@suse.com, josef@toxicpanda.com, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org
ci-upstream-kmsan-gce-386	2020/10/26 01:00	https://github.com/google/kmsan.git master	e1617422	a1839e81	.config	log	report	info	clm@fb.com, dsterba@suse.com, josef@toxicpanda.com, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org
ci-upstream-kmsan-gce-386	2020/10/25 23:14	https://github.com/google/kmsan.git master	e1617422	a1839e81	.config	log	report	info	clm@fb.com, dsterba@suse.com, josef@toxicpanda.com, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org
ci-upstream-kmsan-gce-386	2020/10/25 20:48	https://github.com/google/kmsan.git master	e1617422	a1839e81	.config	log	report	info	clm@fb.com, dsterba@suse.com, josef@toxicpanda.com, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org
ci-upstream-kmsan-gce-386	2020/10/25 15:59	https://github.com/google/kmsan.git master	e1617422	a1839e81	.config	log	report	info	clm@fb.com, dsterba@suse.com, josef@toxicpanda.com, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org
ci-upstream-kmsan-gce-386	2020/10/25 08:09	https://github.com/google/kmsan.git master	e1617422	a1839e81	.config	log	report	info	clm@fb.com, dsterba@suse.com, josef@toxicpanda.com, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org
ci-upstream-kmsan-gce-386	2020/10/24 19:36	https://github.com/google/kmsan.git master	e1617422	a1839e81	.config	log	report	info	clm@fb.com, dsterba@suse.com, josef@toxicpanda.com, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org
ci-upstream-kmsan-gce-386	2020/10/24 19:22	https://github.com/google/kmsan.git master	e1617422	a1839e81	.config	log	report	info	clm@fb.com, dsterba@suse.com, josef@toxicpanda.com, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org
ci-upstream-kmsan-gce-386	2020/10/24 16:40	https://github.com/google/kmsan.git master	e1617422	a1839e81	.config	log	report	info	clm@fb.com, dsterba@suse.com, josef@toxicpanda.com, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org
ci-upstream-kmsan-gce-386	2020/10/24 15:39	https://github.com/google/kmsan.git master	e1617422	a1839e81	.config	log	report	info	clm@fb.com, dsterba@suse.com, josef@toxicpanda.com, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org
ci-upstream-kmsan-gce-386	2020/10/24 15:14	https://github.com/google/kmsan.git master	e1617422	a1839e81	.config	log	report	info	clm@fb.com, dsterba@suse.com, josef@toxicpanda.com, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org
ci-upstream-kmsan-gce-386	2020/10/24 14:13	https://github.com/google/kmsan.git master	e1617422	a1839e81	.config	log	report	info	clm@fb.com, dsterba@suse.com, josef@toxicpanda.com, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org
ci-upstream-kmsan-gce-386	2020/10/24 13:31	https://github.com/google/kmsan.git master	e1617422	a1839e81	.config	log	report	info	clm@fb.com, dsterba@suse.com, josef@toxicpanda.com, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org
ci-upstream-kmsan-gce-386	2020/10/24 12:26	https://github.com/google/kmsan.git master	e1617422	a1839e81	.config	log	report	info	clm@fb.com, dsterba@suse.com, josef@toxicpanda.com, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org
ci-upstream-kmsan-gce-386	2020/10/24 11:36	https://github.com/google/kmsan.git master	e1617422	a1839e81	.config	log	report	info	clm@fb.com, dsterba@suse.com, josef@toxicpanda.com, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org
ci-upstream-kmsan-gce-386	2020/10/24 01:54	https://github.com/google/kmsan.git master	e1617422	2bb6666c	.config	log	report	info	clm@fb.com, dsterba@suse.com, josef@toxicpanda.com, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org
ci-upstream-kmsan-gce-386	2020/10/24 00:03	https://github.com/google/kmsan.git master	e1617422	2bb6666c	.config	log	report	info	clm@fb.com, dsterba@suse.com, josef@toxicpanda.com, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org
ci-upstream-kmsan-gce-386	2020/10/23 23:19	https://github.com/google/kmsan.git master	e1617422	2bb6666c	.config	log	report	info	clm@fb.com, dsterba@suse.com, josef@toxicpanda.com, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org
ci-upstream-kmsan-gce-386	2020/10/23 22:17	https://github.com/google/kmsan.git master	e1617422	2bb6666c	.config	log	report	info	clm@fb.com, dsterba@suse.com, josef@toxicpanda.com, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org
ci-upstream-kmsan-gce-386	2020/10/23 21:24	https://github.com/google/kmsan.git master	e1617422	2bb6666c	.config	log	report	info	clm@fb.com, dsterba@suse.com, josef@toxicpanda.com, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org
ci-upstream-kmsan-gce-386	2020/10/23 20:24	https://github.com/google/kmsan.git master	e1617422	2bb6666c	.config	log	report	info	clm@fb.com, dsterba@suse.com, josef@toxicpanda.com, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org
ci-upstream-kmsan-gce-386	2020/10/23 19:07	https://github.com/google/kmsan.git master	e1617422	2bb6666c	.config	log	report	info	clm@fb.com, dsterba@suse.com, josef@toxicpanda.com, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org
ci-upstream-kmsan-gce-386	2020/10/23 10:08	https://github.com/google/kmsan.git master	e1617422	4e740c00	.config	log	report	info	clm@fb.com, dsterba@suse.com, josef@toxicpanda.com, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org
ci-upstream-kmsan-gce-386	2020/10/23 04:51	https://github.com/google/kmsan.git master	e1617422	4e740c00	.config	log	report	info	clm@fb.com, dsterba@suse.com, josef@toxicpanda.com, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org
ci-upstream-kmsan-gce-386	2020/10/23 01:41	https://github.com/google/kmsan.git master	e1617422	4e740c00	.config	log	report	info	clm@fb.com, dsterba@suse.com, josef@toxicpanda.com, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org
ci-upstream-kmsan-gce-386	2020/10/23 01:13	https://github.com/google/kmsan.git master	e1617422	4e740c00	.config	log	report	info	clm@fb.com, dsterba@suse.com, josef@toxicpanda.com, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org
ci-upstream-kmsan-gce-386	2020/10/23 00:08	https://github.com/google/kmsan.git master	e1617422	4e740c00	.config	log	report	info	clm@fb.com, dsterba@suse.com, josef@toxicpanda.com, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org
ci-upstream-kmsan-gce-386	2020/10/22 23:30	https://github.com/google/kmsan.git master	e1617422	4e740c00	.config	log	report	info	clm@fb.com, dsterba@suse.com, josef@toxicpanda.com, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org
ci-upstream-kmsan-gce-386	2020/10/22 22:24	https://github.com/google/kmsan.git master	e1617422	4e740c00	.config	log	report	info	clm@fb.com, dsterba@suse.com, josef@toxicpanda.com, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org
ci-upstream-kmsan-gce-386	2020/10/22 22:06	https://github.com/google/kmsan.git master	e1617422	4e740c00	.config	log	report	info	clm@fb.com, dsterba@suse.com, josef@toxicpanda.com, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org
ci-upstream-kmsan-gce-386	2020/10/22 21:05	https://github.com/google/kmsan.git master	e1617422	4e740c00	.config	log	report	info	clm@fb.com, dsterba@suse.com, josef@toxicpanda.com, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org
ci-upstream-kmsan-gce-386	2020/10/22 20:01	https://github.com/google/kmsan.git master	e1617422	be6b1582	.config	log	report	info	clm@fb.com, dsterba@suse.com, josef@toxicpanda.com, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org
ci-upstream-kmsan-gce-386	2020/10/22 18:26	https://github.com/google/kmsan.git master	e1617422	be6b1582	.config	log	report	info	clm@fb.com, dsterba@suse.com, josef@toxicpanda.com, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org
ci-upstream-kmsan-gce-386	2020/10/22 04:54	https://github.com/google/kmsan.git master	e1617422	be6b1582	.config	log	report	info	clm@fb.com, dsterba@suse.com, josef@toxicpanda.com, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org
ci-upstream-kmsan-gce-386	2020/10/22 03:46	https://github.com/google/kmsan.git master	e1617422	be6b1582	.config	log	report	info	clm@fb.com, dsterba@suse.com, josef@toxicpanda.com, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org
ci-upstream-kmsan-gce-386	2020/10/22 03:03	https://github.com/google/kmsan.git master	e1617422	be6b1582	.config	log	report	info	clm@fb.com, dsterba@suse.com, josef@toxicpanda.com, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org
ci-upstream-kmsan-gce-386	2020/09/19 08:10	https://github.com/google/kmsan.git master	c5a13b33	53ce8104	.config	log	report	info	clm@fb.com, dsterba@suse.com, josef@toxicpanda.com, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org
ci-upstream-kmsan-gce-386	2020/09/15 08:08	https://github.com/google/kmsan.git master	3b3ea602	6989d6f6	.config	log	report	info	clm@fb.com, dsterba@suse.com, josef@toxicpanda.com, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org
ci-upstream-kmsan-gce-386	2020/09/15 07:53	https://github.com/google/kmsan.git master	3b3ea602	6989d6f6	.config	log	report	info	clm@fb.com, dsterba@suse.com, josef@toxicpanda.com, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org