[syzbot] [sctp?] KMSAN: uninit-value in sctp_sf_ootb

[syzbot <syzbot+f0cbb34d39392f2746ca@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    d2bafcf224f3 Merge tag 'cgroup-for-6.11-rc4-fixes' of git:..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=15e9b7f5980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=62f882de896675a6
dashboard link: https://syzkaller.appspot.com/bug?extid=f0cbb34d39392f2746ca
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/17f6ee87834d/disk-d2bafcf2.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/7783769858d1/vmlinux-d2bafcf2.xz
kernel image: https://storage.googleapis.com/syzbot-assets/45248109d188/bzImage-d2bafcf2.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+f0cbb34d39392f2746ca@syzkaller.appspotmail.com

=====================================================
BUG: KMSAN: uninit-value in sctp_sf_ootb+0x7f5/0xce0 net/sctp/sm_statefuns.c:3702
 sctp_sf_ootb+0x7f5/0xce0 net/sctp/sm_statefuns.c:3702
 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:1158
 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:5661 [inline]
 __netif_receive_skb+0x319/0xa00 net/core/dev.c:5775
 netif_receive_skb_internal net/core/dev.c:5861 [inline]
 netif_receive_skb+0x58/0x660 net/core/dev.c:5921
 tun_rx_batched+0x3ee/0x980 drivers/net/tun.c:1549
 tun_get_user+0x5677/0x6b50 drivers/net/tun.c:2006
 tun_chr_write_iter+0x3af/0x5d0 drivers/net/tun.c:2052
 new_sync_write fs/read_write.c:497 [inline]
 vfs_write+0xb2f/0x1550 fs/read_write.c:590
 ksys_write+0x20f/0x4c0 fs/read_write.c:643
 __do_sys_write fs/read_write.c:655 [inline]
 __se_sys_write fs/read_write.c:652 [inline]
 __x64_sys_write+0x93/0xe0 fs/read_write.c:652
 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:3994 [inline]
 slab_alloc_node mm/slub.c:4037 [inline]
 kmem_cache_alloc_node_noprof+0x6bf/0xb80 mm/slub.c:4080
 kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:583
 pskb_expand_head+0x222/0x19c0 net/core/skbuff.c:2259
 __skb_cow include/linux/skbuff.h:3646 [inline]
 skb_cow include/linux/skbuff.h:3665 [inline]
 ip_rcv_options net/ipv4/ip_input.c:272 [inline]
 ip_rcv_finish_core+0xf3d/0x1fe0 net/ipv4/ip_input.c:387
 ip_rcv_finish+0x2cc/0x520 net/ipv4/ip_input.c:447
 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:5661 [inline]
 __netif_receive_skb+0x319/0xa00 net/core/dev.c:5775
 netif_receive_skb_internal net/core/dev.c:5861 [inline]
 netif_receive_skb+0x58/0x660 net/core/dev.c:5921
 tun_rx_batched+0x3ee/0x980 drivers/net/tun.c:1549
 tun_get_user+0x5677/0x6b50 drivers/net/tun.c:2006
 tun_chr_write_iter+0x3af/0x5d0 drivers/net/tun.c:2052
 new_sync_write fs/read_write.c:497 [inline]
 vfs_write+0xb2f/0x1550 fs/read_write.c:590
 ksys_write+0x20f/0x4c0 fs/read_write.c:643
 __do_sys_write fs/read_write.c:655 [inline]
 __se_sys_write fs/read_write.c:652 [inline]
 __x64_sys_write+0x93/0xe0 fs/read_write.c:652
 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: 13990 Comm: syz.3.1326 Not tainted 6.11.0-rc4-syzkaller-00255-gd2bafcf224f3 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
=====================================================


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