Re: [syzbot] [net?] [nfc?] KMSAN: uninit-value in nci_ntf_packet (3)

[syzbot <syzbot+3f8fa0edaa75710cd66e@syzkaller.appspotmail.com>]

syzbot has found a reproducer for the following issue on:

HEAD commit:    8f602276d390 Merge tag 'bcachefs-2024-10-05' of git://evil..
git tree:       upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=148c27d0580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=d302f14701986aa0
dashboard link: https://syzkaller.appspot.com/bug?extid=3f8fa0edaa75710cd66e
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1367f307980000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=14c98327980000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/241996bfa3de/disk-8f602276.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/417de1b4ca32/vmlinux-8f602276.xz
kernel image: https://storage.googleapis.com/syzbot-assets/2c793c19b953/bzImage-8f602276.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+3f8fa0edaa75710cd66e@syzkaller.appspotmail.com

nci: nci_rf_discover_ntf_packet: unsupported rf_tech_and_mode 0xe6
=====================================================
BUG: KMSAN: uninit-value in nci_rf_discover_ntf_packet net/nfc/nci/ntf.c:386 [inline]
BUG: KMSAN: uninit-value in nci_ntf_packet+0x2ac6/0x39c0 net/nfc/nci/ntf.c:798
 nci_rf_discover_ntf_packet net/nfc/nci/ntf.c:386 [inline]
 nci_ntf_packet+0x2ac6/0x39c0 net/nfc/nci/ntf.c:798
 nci_rx_work+0x408/0x6f0 net/nfc/nci/core.c:1544
 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]
 kmem_cache_alloc_node_noprof+0x6bf/0xb80 mm/slub.c:4186
 kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:587
 __alloc_skb+0x363/0x7b0 net/core/skbuff.c:678
 alloc_skb include/linux/skbuff.h:1322 [inline]
 virtual_ncidev_write+0x67/0x380 drivers/nfc/virtual_ncidev.c:120
 vfs_write+0x487/0x1540 fs/read_write.c:681
 ksys_write+0x24f/0x4c0 fs/read_write.c:736
 __do_sys_write fs/read_write.c:748 [inline]
 __se_sys_write fs/read_write.c:745 [inline]
 __x64_sys_write+0x93/0xe0 fs/read_write.c:745
 x64_sys_call+0x306a/0x3ba0 arch/x86/include/generated/asm/syscalls_64.h:2
 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: 1 UID: 0 PID: 2937 Comm: kworker/u8:9 Not tainted 6.12.0-rc1-syzkaller-00349-g8f602276d390 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: nfc2_nci_rx_wq nci_rx_work
=====================================================


---
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.