syzbot has found a reproducer for the following issue on: HEAD commit: 819837584309 Linux 6.12-rc5 git tree: upstream console+strace: https://syzkaller.appspot.com/x/log.txt?x=1211e940580000 kernel config: https://syzkaller.appspot.com/x/.config?x=4d4311df74eee96f dashboard link: https://syzkaller.appspot.com/bug?extid=f0cbb34d39392f2746ca 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=11eb3230580000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11f36ca7980000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/dfa054090a8f/disk-81983758.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/54edfdbd151e/vmlinux-81983758.xz kernel image: https://storage.googleapis.com/syzbot-assets/d63a317b80f9/bzImage-81983758.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+f0cbb34d39392f2746ca@xxxxxxxxxxxxxxxxxxxxxxxxx syz-executor341 uses obsolete (PF_INET,SOCK_PACKET) ===================================================== BUG: KMSAN: uninit-value in sctp_sf_ootb+0x7f5/0xce0 net/sctp/sm_statefuns.c:3712 sctp_sf_ootb+0x7f5/0xce0 net/sctp/sm_statefuns.c:3712 sctp_do_sm+0x181/0x93d0 net/sctp/sm_sideeffect.c:1166 sctp_endpoint_bh_rcv+0xc38/0xf90 net/sctp/endpointola.c:407 sctp_inq_push+0x2ef/0x380 net/sctp/inqueue.c:88 sctp_rcv+0x3831/0x3b20 net/sctp/input.c:243 sctp4_rcv+0x42/0x50 net/sctp/protocol.c:1159 ip_protocol_deliver_rcu+0xb51/0x13d0 net/ipv4/ip_input.c:205 ip_local_deliver_finish+0x336/0x500 net/ipv4/ip_input.c:233 NF_HOOK include/linux/netfilter.h:314 [inline] ip_local_deliver+0x21f/0x490 net/ipv4/ip_input.c:254 dst_input include/net/dst.h:460 [inline] ip_rcv_finish+0x4a2/0x520 net/ipv4/ip_input.c:449 NF_HOOK include/linux/netfilter.h:314 [inline] ip_rcv+0xcd/0x380 net/ipv4/ip_input.c:569 __netif_receive_skb_one_core net/core/dev.c:5666 [inline] __netif_receive_skb+0x319/0xa00 net/core/dev.c:5779 netif_receive_skb_internal net/core/dev.c:5865 [inline] netif_receive_skb+0x58/0x660 net/core/dev.c:5924 tun_rx_batched+0x3ee/0x980 drivers/net/tun.c:1550 tun_get_user+0x5783/0x6c60 drivers/net/tun.c:2007 tun_chr_write_iter+0x3ac/0x5d0 drivers/net/tun.c:2053 new_sync_write fs/read_write.c:590 [inline] vfs_write+0xb2b/0x1540 fs/read_write.c:683 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 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] alloc_skb_with_frags+0xc8/0xd00 net/core/skbuff.c:6612 sock_alloc_send_pskb+0xa81/0xbf0 net/core/sock.c:2883 tun_alloc_skb drivers/net/tun.c:1526 [inline] tun_get_user+0x20f4/0x6c60 drivers/net/tun.c:1851 tun_chr_write_iter+0x3ac/0x5d0 drivers/net/tun.c:2053 new_sync_write fs/read_write.c:590 [inline] vfs_write+0xb2b/0x1540 fs/read_write.c:683 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: 0 UID: 0 PID: 5818 Comm: syz-executor341 Not tainted 6.12.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 ===================================================== --- 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.
