[syzbot] upstream boot error: KMSAN: uninit-value in strlcat

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 16a8829130ca nfs: fix another case of NULL/IS_ERR confusio..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=10811e34280000
kernel config: https://syzkaller.appspot.com/x/.config?x=a7a1059074b7bdce
dashboard link: https://syzkaller.appspot.com/bug?extid=26836cb949db3d40c992
compiler: Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/d4c6da24829a/disk-16a88291.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/7b2a0fc666c9/vmlinux-16a88291.xz
kernel image: https://storage.googleapis.com/syzbot-assets/710105c78106/bzImage-16a88291.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+26836c...@syzkaller.appspotmail.com

sd 0:0:1:0: [sda] 4194304 512-byte logical blocks: (2.15 GB/2.00 GiB)
sd 0:0:1:0: [sda] 4096-byte physical blocks
sd 0:0:1:0: [sda] Write Protect is off
sd 0:0:1:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
=====================================================
BUG: KMSAN: uninit-value in strlen lib/string.c:418 [inline]
BUG: KMSAN: uninit-value in strlcat+0x67/0x160 lib/string.c:252
strlen lib/string.c:418 [inline]
strlcat+0x67/0x160 lib/string.c:252
msdos_partition+0x366d/0x46a0 block/partitions/msdos.c:696
check_partition block/partitions/core.c:138 [inline]
blk_add_partitions block/partitions/core.c:594 [inline]
bdev_disk_changed+0xab5/0x2070 block/partitions/core.c:680
blkdev_get_whole+0x633/0x6c0 block/bdev.c:619
blkdev_get_by_dev+0x50f/0x1200 block/bdev.c:756
disk_scan_partitions+0x2d8/0x3d0 block/genhd.c:379
device_add_disk+0x16d9/0x17b0 block/genhd.c:519
sd_probe+0x132e/0x1710 drivers/scsi/sd.c:3587
really_probe+0x506/0xf40 drivers/base/dd.c:658
__driver_probe_device+0x2a7/0x5d0 drivers/base/dd.c:800
driver_probe_device+0x72/0x7b0 drivers/base/dd.c:830
__device_attach_driver+0x55a/0x8f0 drivers/base/dd.c:958
bus_for_each_drv+0x3ff/0x620 drivers/base/bus.c:457
__device_attach_async_helper+0x208/0x2b0 drivers/base/dd.c:987
async_run_entry_fn+0x97/0x420 kernel/async.c:127
process_one_work+0xb0d/0x1410 kernel/workqueue.c:2405
worker_thread+0x107e/0x1d60 kernel/workqueue.c:2552
kthread+0x3e8/0x540 kernel/kthread.c:379
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

Uninit was created at:
__alloc_pages+0x9a4/0xe00 mm/page_alloc.c:4791
alloc_pages+0xd01/0x1040
__get_free_pages+0x34/0xc0 mm/page_alloc.c:4818
check_partition block/partitions/core.c:122 [inline]
blk_add_partitions block/partitions/core.c:594 [inline]
bdev_disk_changed+0x63c/0x2070 block/partitions/core.c:680
blkdev_get_whole+0x633/0x6c0 block/bdev.c:619
blkdev_get_by_dev+0x50f/0x1200 block/bdev.c:756
disk_scan_partitions+0x2d8/0x3d0 block/genhd.c:379
device_add_disk+0x16d9/0x17b0 block/genhd.c:519
sd_probe+0x132e/0x1710 drivers/scsi/sd.c:3587
really_probe+0x506/0xf40 drivers/base/dd.c:658
__driver_probe_device+0x2a7/0x5d0 drivers/base/dd.c:800
driver_probe_device+0x72/0x7b0 drivers/base/dd.c:830
__device_attach_driver+0x55a/0x8f0 drivers/base/dd.c:958
bus_for_each_drv+0x3ff/0x620 drivers/base/bus.c:457
__device_attach_async_helper+0x208/0x2b0 drivers/base/dd.c:987
async_run_entry_fn+0x97/0x420 kernel/async.c:127
process_one_work+0xb0d/0x1410 kernel/workqueue.c:2405
worker_thread+0x107e/0x1d60 kernel/workqueue.c:2552
kthread+0x3e8/0x540 kernel/kthread.c:379
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

CPU: 1 PID: 1018 Comm: kworker/u4:5 Not tainted 6.4.0-rc1-syzkaller-00012-g16a8829130ca #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023
Workqueue: events_unbound async_run_entry_fn

=====================================================


---
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[Alexander Potapenko]

On Thu, May 11, 2023 at 8:58 AM syzbot
<syzbot+26836c...@syzkaller.appspotmail.com> wrote:
>
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: 16a8829130ca nfs: fix another case of NULL/IS_ERR confusio..
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=10811e34280000
> kernel config: https://syzkaller.appspot.com/x/.config?x=a7a1059074b7bdce
> dashboard link: https://syzkaller.appspot.com/bug?extid=26836cb949db3d40c992
> compiler: Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2

Sorry for the noise, I was trying to switch KMSAN bots to the upstream
tree (it is not ready yet, needs one more patch), and accidentally
sent this report to LKML. Please disregard it.

[Alexander Potapenko]

#syz invalid