syzbot


KMSAN: uninit-value in netfs_clear_buffer

Status: upstream: reported C repro on 2024/09/20 17:00
Subsystems: netfs
[Documentation on labels]
Reported-by: syzbot+921873345a95f4dae7e9@syzkaller.appspotmail.com
First crash: 4d07h, last: 2d17h
Discussions (2)
Title Replies (including bot) Last reply
Re: [syzbot] [PATCH] netfs: Fix a KMSAN uninit-value error in netfs_clear_buffer 0 (1) 2024/09/21 00:23
[syzbot] [netfs?] KMSAN: uninit-value in netfs_clear_buffer 0 (1) 2024/09/20 17:00
Last patch testing requests (1)
Created Duration User Patch Repo Result
2024/09/21 00:23 marcus.yu.56@gmail.com patch upstream running

Sample crash report:
=====================================================
BUG: KMSAN: uninit-value in netfs_clear_buffer+0x216/0x4e0 fs/netfs/misc.c:75
 netfs_clear_buffer+0x216/0x4e0 fs/netfs/misc.c:75
 netfs_free_request+0x51f/0x890 fs/netfs/objects.c:146
 netfs_put_request+0x161/0x360 fs/netfs/objects.c:170
 netfs_write_collection_worker+0x7337/0x7c20
 process_one_work kernel/workqueue.c:3231 [inline]
 process_scheduled_works+0xae0/0x1c40 kernel/workqueue.c:3312
 worker_thread+0xea7/0x14f0 kernel/workqueue.c:3393
 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

Uninit was created at:
 slab_post_alloc_hook mm/slub.c:3995 [inline]
 slab_alloc_node mm/slub.c:4038 [inline]
 __kmalloc_cache_noprof+0x4f0/0xb00 mm/slub.c:4185
 kmalloc_noprof include/linux/slab.h:690 [inline]
 netfs_buffer_append_folio+0x2cf/0x8b0 fs/netfs/misc.c:25
 netfs_write_folio+0x1120/0x3050 fs/netfs/write_issue.c:421
 netfs_writepages+0xe60/0x1670 fs/netfs/write_issue.c:541
 do_writepages+0x427/0xc30 mm/page-writeback.c:2683
 filemap_fdatawrite_wbc+0x1d8/0x270 mm/filemap.c:397
 __filemap_fdatawrite_range mm/filemap.c:430 [inline]
 __filemap_fdatawrite mm/filemap.c:436 [inline]
 filemap_fdatawrite+0xbf/0xf0 mm/filemap.c:441
 v9fs_dir_release+0x1f2/0x810 fs/9p/vfs_dir.c:219
 __fput+0x32c/0x1120 fs/file_table.c:431
 ____fput+0x25/0x30 fs/file_table.c:459
 task_work_run+0x268/0x310 kernel/task_work.c:228
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0xd88/0x4050 kernel/exit.c:882
 do_group_exit+0x2fe/0x390 kernel/exit.c:1031
 __do_sys_exit_group kernel/exit.c:1042 [inline]
 __se_sys_exit_group kernel/exit.c:1040 [inline]
 __x64_sys_exit_group+0x3c/0x50 kernel/exit.c:1040
 x64_sys_call+0x3b9a/0x3ba0 arch/x86/include/generated/asm/syscalls_64.h:232
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

CPU: 0 UID: 0 PID: 2945 Comm: kworker/u8:9 Not tainted 6.11.0-syzkaller-04557-g2f27fce67173 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
Workqueue: events_unbound netfs_write_collection_worker
=====================================================

Crashes (7):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/09/18 07:18 upstream 2f27fce67173 c673ca06 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in netfs_clear_buffer
2024/09/18 04:27 upstream 2f27fce67173 c673ca06 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in netfs_clear_buffer
2024/09/17 08:53 upstream a430d95c5efa c673ca06 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in netfs_clear_buffer
2024/09/17 08:33 upstream a430d95c5efa c673ca06 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in netfs_clear_buffer
2024/09/17 05:52 upstream a430d95c5efa c673ca06 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in netfs_clear_buffer
2024/09/16 16:55 upstream adfc3ded5c33 49cf0773 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in netfs_clear_buffer
2024/09/16 16:54 upstream adfc3ded5c33 49cf0773 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in netfs_clear_buffer
* Struck through repros no longer work on HEAD.