linux-kernel - [syzbot] [hams?] KMSAN: uninit-value in sixpack_receive

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Message-ID: <6743d9f6.050a0220.1cc393.0054.GAE@google.com>
Date: Sun, 24 Nov 2024 17:59:18 -0800
From: syzbot <syzbot+c08839217d2085e56bb8@...kaller.appspotmail.com>
To: ajk@...nets.uni-bremen.de, andrew+netdev@...n.ch, davem@...emloft.net, 
	edumazet@...gle.com, kuba@...nel.org, linux-hams@...r.kernel.org, 
	linux-kernel@...r.kernel.org, netdev@...r.kernel.org, pabeni@...hat.com, 
	syzkaller-bugs@...glegroups.com
Subject: [syzbot] [hams?] KMSAN: uninit-value in sixpack_receive_buf

Hello,

syzbot found the following issue on:

HEAD commit:    bf9aa14fc523 Merge tag 'timers-core-2024-11-18' of git://g..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=16d7bae8580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=1eb27d66c540f6e6
dashboard link: https://syzkaller.appspot.com/bug?extid=c08839217d2085e56bb8
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/c0c0e51a2a13/disk-bf9aa14f.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/852f5ece75d3/vmlinux-bf9aa14f.xz
kernel image: https://storage.googleapis.com/syzbot-assets/4fb1796345b4/bzImage-bf9aa14f.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c08839217d2085e56bb8@...kaller.appspotmail.com

=====================================================
BUG: KMSAN: uninit-value in sixpack_decode drivers/net/hamradio/6pack.c:938 [inline]
BUG: KMSAN: uninit-value in sixpack_receive_buf+0x773/0x2d70 drivers/net/hamradio/6pack.c:447
 sixpack_decode drivers/net/hamradio/6pack.c:938 [inline]
 sixpack_receive_buf+0x773/0x2d70 drivers/net/hamradio/6pack.c:447
 tty_ldisc_receive_buf+0x202/0x290 drivers/tty/tty_buffer.c:391
 tty_port_default_receive_buf+0xdf/0x190 drivers/tty/tty_port.c:37
 receive_buf drivers/tty/tty_buffer.c:445 [inline]
 flush_to_ldisc+0x473/0xdb0 drivers/tty/tty_buffer.c:495
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xae0/0x1c40 kernel/workqueue.c:3310
 worker_thread+0xea7/0x14f0 kernel/workqueue.c:3391
 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:4091 [inline]
 slab_alloc_node mm/slub.c:4134 [inline]
 __do_kmalloc_node mm/slub.c:4263 [inline]
 __kmalloc_noprof+0x661/0xf30 mm/slub.c:4276
 kmalloc_noprof include/linux/slab.h:883 [inline]
 tty_buffer_alloc drivers/tty/tty_buffer.c:180 [inline]
 __tty_buffer_request_room+0x36e/0x6d0 drivers/tty/tty_buffer.c:273
 __tty_insert_flip_string_flags+0x140/0x570 drivers/tty/tty_buffer.c:309
 tty_insert_flip_char include/linux/tty_flip.h:77 [inline]
 uart_insert_char+0x39e/0xa10 drivers/tty/serial/serial_core.c:3550
 serial8250_read_char+0x1a7/0x5d0 drivers/tty/serial/8250/8250_port.c:1743
 serial8250_rx_chars drivers/tty/serial/8250/8250_port.c:1760 [inline]
 serial8250_handle_irq+0x970/0x1130 drivers/tty/serial/8250/8250_port.c:1924
 serial8250_default_handle_irq+0x120/0x2b0 drivers/tty/serial/8250/8250_port.c:1949
 serial8250_interrupt+0xc5/0x360 drivers/tty/serial/8250/8250_core.c:86
 __handle_irq_event_percpu+0x118/0xca0 kernel/irq/handle.c:158
 handle_irq_event_percpu kernel/irq/handle.c:193 [inline]
 handle_irq_event+0xef/0x2c0 kernel/irq/handle.c:210
 handle_edge_irq+0x340/0xfb0 kernel/irq/chip.c:831
 generic_handle_irq_desc include/linux/irqdesc.h:173 [inline]
 handle_irq arch/x86/kernel/irq.c:247 [inline]
 call_irq_handler arch/x86/kernel/irq.c:259 [inline]
 __common_interrupt+0x97/0x1f0 arch/x86/kernel/irq.c:285
 common_interrupt+0x92/0xb0 arch/x86/kernel/irq.c:278
 asm_common_interrupt+0x2b/0x40 arch/x86/include/asm/idtentry.h:693

CPU: 1 UID: 0 PID: 7175 Comm: kworker/u8:31 Not tainted 6.12.0-syzkaller-01782-gbf9aa14fc523 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024
Workqueue: events_unbound flush_to_ldisc
=====================================================


---
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