syzbot has found a reproducer for the following issue on: HEAD commit: ec2df4364666 Merge tag 'spi-fix-v6.16-rc7' of git://git.ke.. git tree: upstream console+strace: https://syzkaller.appspot.com/x/log.txt?x=126d74f0580000 kernel config: https://syzkaller.appspot.com/x/.config?x=7753c32e11ff6a95 dashboard link: https://syzkaller.appspot.com/bug?extid=773e51afe420baaf0e2b compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14e838a2580000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1084a782580000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/3f86f1075111/disk-ec2df436.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/c90594c19d7f/vmlinux-ec2df436.xz kernel image: https://storage.googleapis.com/syzbot-assets/8eac8db13156/bzImage-ec2df436.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+773e51afe420baaf0e2b@xxxxxxxxxxxxxxxxxxxxxxxxx ===================================================== BUG: KMSAN: uninit-value in sctp_assoc_bh_rcv+0x34e/0xbc0 net/sctp/associola.c:987 sctp_assoc_bh_rcv+0x34e/0xbc0 net/sctp/associola.c:987 sctp_inq_push+0x2a3/0x350 net/sctp/inqueue.c:88 sctp_backlog_rcv+0x3c7/0xda0 net/sctp/input.c:331 sk_backlog_rcv+0x142/0x420 include/net/sock.h:1148 __release_sock+0x1d3/0x330 net/core/sock.c:3213 release_sock+0x6b/0x270 net/core/sock.c:3767 sctp_wait_for_connect+0x458/0x820 net/sctp/socket.c:9367 sctp_sendmsg_to_asoc+0x223a/0x2260 net/sctp/socket.c:1886 sctp_sendmsg+0x3910/0x49f0 net/sctp/socket.c:2032 inet_sendmsg+0x269/0x2a0 net/ipv4/af_inet.c:851 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg+0x278/0x3d0 net/socket.c:727 __sys_sendto+0x593/0x720 net/socket.c:2180 __do_sys_sendto net/socket.c:2187 [inline] __se_sys_sendto net/socket.c:2183 [inline] __x64_sys_sendto+0x130/0x200 net/socket.c:2183 x64_sys_call+0x3c0b/0x3db0 arch/x86/include/generated/asm/syscalls_64.h:45 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xd9/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Uninit was created at: slab_post_alloc_hook mm/slub.c:4154 [inline] slab_alloc_node mm/slub.c:4197 [inline] __do_kmalloc_node mm/slub.c:4327 [inline] __kmalloc_node_track_caller_noprof+0x96d/0x12f0 mm/slub.c:4347 kmalloc_reserve+0x22f/0x4b0 net/core/skbuff.c:601 __alloc_skb+0x347/0x7d0 net/core/skbuff.c:670 alloc_skb include/linux/skbuff.h:1336 [inline] sctp_packet_pack net/sctp/output.c:472 [inline] sctp_packet_transmit+0x18a1/0x46d0 net/sctp/output.c:621 sctp_outq_flush_transports net/sctp/outqueue.c:1173 [inline] sctp_outq_flush+0x1c7d/0x67c0 net/sctp/outqueue.c:1221 sctp_outq_uncork+0x9e/0xc0 net/sctp/outqueue.c:764 sctp_cmd_interpreter net/sctp/sm_sideeffect.c:-1 [inline] sctp_side_effects net/sctp/sm_sideeffect.c:1204 [inline] sctp_do_sm+0x8c8e/0x9720 net/sctp/sm_sideeffect.c:1175 sctp_assoc_bh_rcv+0x88b/0xbc0 net/sctp/associola.c:1034 sctp_inq_push+0x2a3/0x350 net/sctp/inqueue.c:88 sctp_backlog_rcv+0x3c7/0xda0 net/sctp/input.c:331 sk_backlog_rcv+0x142/0x420 include/net/sock.h:1148 __release_sock+0x1d3/0x330 net/core/sock.c:3213 release_sock+0x6b/0x270 net/core/sock.c:3767 sctp_wait_for_connect+0x458/0x820 net/sctp/socket.c:9367 sctp_sendmsg_to_asoc+0x223a/0x2260 net/sctp/socket.c:1886 sctp_sendmsg+0x3910/0x49f0 net/sctp/socket.c:2032 inet_sendmsg+0x269/0x2a0 net/ipv4/af_inet.c:851 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg+0x278/0x3d0 net/socket.c:727 __sys_sendto+0x593/0x720 net/socket.c:2180 __do_sys_sendto net/socket.c:2187 [inline] __se_sys_sendto net/socket.c:2183 [inline] __x64_sys_sendto+0x130/0x200 net/socket.c:2183 x64_sys_call+0x3c0b/0x3db0 arch/x86/include/generated/asm/syscalls_64.h:45 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xd9/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f CPU: 0 UID: 0 PID: 5812 Comm: syz-executor343 Not tainted 6.16.0-rc7-syzkaller-00140-gec2df4364666 #0 PREEMPT(none) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 ===================================================== --- 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.
