===================================================== BUG: KMSAN: uninit-value in __arch_swab32 arch/x86/include/uapi/asm/swab.h:10 [inline] BUG: KMSAN: uninit-value in __fswab32 include/uapi/linux/swab.h:60 [inline] BUG: KMSAN: uninit-value in sctp_ootb_pkt_new+0x57e/0x5a0 net/sctp/sm_statefuns.c:6257 CPU: 0 PID: 27828 Comm: syz-executor.5 Not tainted 5.8.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x21c/0x280 lib/dump_stack.c:118 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:121 __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:215 __arch_swab32 arch/x86/include/uapi/asm/swab.h:10 [inline] __fswab32 include/uapi/linux/swab.h:60 [inline] sctp_ootb_pkt_new+0x57e/0x5a0 net/sctp/sm_statefuns.c:6257 sctp_sf_tabort_8_4_8+0xee/0x830 net/sctp/sm_statefuns.c:3373 sctp_sf_do_5_1B_init+0x6e7/0x1c70 net/sctp/sm_statefuns.c:337 sctp_do_sm+0x29c/0xa260 net/sctp/sm_sideeffect.c:1153 sctp_endpoint_bh_rcv+0xe00/0x10d0 net/sctp/endpointola.c:395 sctp_inq_push+0x31c/0x440 net/sctp/inqueue.c:80 sctp_rcv+0x568c/0x6120 net/sctp/input.c:256 ip_protocol_deliver_rcu+0x572/0xc50 net/ipv4/ip_input.c:204 ip_local_deliver_finish net/ipv4/ip_input.c:231 [inline] NF_HOOK include/linux/netfilter.h:307 [inline] ip_local_deliver+0x727/0x8d0 net/ipv4/ip_input.c:252 dst_input include/net/dst.h:449 [inline] ip_rcv_finish net/ipv4/ip_input.c:428 [inline] NF_HOOK include/linux/netfilter.h:307 [inline] ip_rcv+0x795/0x810 net/ipv4/ip_input.c:539 __netif_receive_skb_one_core net/core/dev.c:5281 [inline] __netif_receive_skb+0x265/0x670 net/core/dev.c:5395 netif_receive_skb_internal+0x33c/0x3b0 net/core/dev.c:5497 netif_receive_skb+0x1c1/0x360 net/core/dev.c:5556 tun_rx_batched include/linux/skbuff.h:4327 [inline] tun_get_user+0x63f6/0x66e0 drivers/net/tun.c:1972 tun_chr_write_iter+0x1f2/0x360 drivers/net/tun.c:2001 call_write_iter include/linux/fs.h:1908 [inline] new_sync_write fs/read_write.c:503 [inline] vfs_write+0xf9a/0x17c0 fs/read_write.c:578 ksys_write+0x275/0x500 fs/read_write.c:631 __do_sys_write fs/read_write.c:643 [inline] __se_sys_write+0x92/0xb0 fs/read_write.c:640 __ia32_sys_write+0x4a/0x70 fs/read_write.c:640 do_syscall_32_irqs_on arch/x86/entry/common.c:430 [inline] __do_fast_syscall_32+0x2af/0x480 arch/x86/entry/common.c:477 do_fast_syscall_32+0x6b/0xd0 arch/x86/entry/common.c:505 do_SYSENTER_32+0x73/0x90 arch/x86/entry/common.c:554 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c RIP: 0023:0xf7fac549 Code: Bad RIP value. RSP: 002b:00000000f55a60cc EFLAGS: 00000296 ORIG_RAX: 0000000000000004 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000020000000 RDX: 000000000000002e RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Uninit was created at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:144 [inline] kmsan_internal_poison_shadow+0x66/0xd0 mm/kmsan/kmsan.c:127 kmsan_slab_alloc+0x8a/0xe0 mm/kmsan/kmsan_hooks.c:80 slab_alloc_node mm/slub.c:2839 [inline] __kmalloc_node_track_caller+0xeab/0x12e0 mm/slub.c:4478 __kmalloc_reserve net/core/skbuff.c:142 [inline] __alloc_skb+0x35f/0xb30 net/core/skbuff.c:210 alloc_skb include/linux/skbuff.h:1083 [inline] alloc_skb_with_frags+0x1f2/0xc10 net/core/skbuff.c:5770 sock_alloc_send_pskb+0xc83/0xe50 net/core/sock.c:2356 tun_alloc_skb drivers/net/tun.c:1494 [inline] tun_get_user+0x1a32/0x66e0 drivers/net/tun.c:1811 tun_chr_write_iter+0x1f2/0x360 drivers/net/tun.c:2001 call_write_iter include/linux/fs.h:1908 [inline] new_sync_write fs/read_write.c:503 [inline] vfs_write+0xf9a/0x17c0 fs/read_write.c:578 ksys_write+0x275/0x500 fs/read_write.c:631 __do_sys_write fs/read_write.c:643 [inline] __se_sys_write+0x92/0xb0 fs/read_write.c:640 __ia32_sys_write+0x4a/0x70 fs/read_write.c:640 do_syscall_32_irqs_on arch/x86/entry/common.c:430 [inline] __do_fast_syscall_32+0x2af/0x480 arch/x86/entry/common.c:477 do_fast_syscall_32+0x6b/0xd0 arch/x86/entry/common.c:505 do_SYSENTER_32+0x73/0x90 arch/x86/entry/common.c:554 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c =====================================================