===================================================== 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+0x202/0x540 net/sctp/sm_statefuns.c:6256 CPU: 1 PID: 11557 Comm: syz-executor.2 Not tainted 5.7.0-rc4-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+0x1c9/0x220 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+0x202/0x540 net/sctp/sm_statefuns.c:6256 sctp_sf_tabort_8_4_8+0xe6/0x7e0 net/sctp/sm_statefuns.c:3372 sctp_sf_do_5_1B_init+0x6be/0x1b60 net/sctp/sm_statefuns.c:338 sctp_do_sm+0x2b4/0x9a30 net/sctp/sm_sideeffect.c:1153 sctp_endpoint_bh_rcv+0xd54/0xfe0 net/sctp/endpointola.c:395 sctp_inq_push+0x300/0x420 net/sctp/inqueue.c:80 sctp_rcv+0x48b9/0x5410 net/sctp/input.c:256 ip_protocol_deliver_rcu+0x700/0xbc0 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+0x62a/0x7c0 net/ipv4/ip_input.c:252 dst_input include/net/dst.h:441 [inline] ip_rcv_finish net/ipv4/ip_input.c:428 [inline] NF_HOOK include/linux/netfilter.h:307 [inline] ip_rcv+0x6cf/0x750 net/ipv4/ip_input.c:539 __netif_receive_skb_one_core net/core/dev.c:5188 [inline] __netif_receive_skb net/core/dev.c:5302 [inline] netif_receive_skb_internal net/core/dev.c:5392 [inline] netif_receive_skb+0xbb5/0xf20 net/core/dev.c:5451 tun_rx_batched drivers/net/tun.c:1516 [inline] tun_get_user+0x6d60/0x71e0 drivers/net/tun.c:1963 tun_chr_write_iter+0x1f2/0x360 drivers/net/tun.c:1992 call_write_iter include/linux/fs.h:1907 [inline] new_sync_write fs/read_write.c:484 [inline] __vfs_write+0xa5a/0xca0 fs/read_write.c:497 vfs_write+0x444/0x8e0 fs/read_write.c:559 ksys_write+0x267/0x450 fs/read_write.c:612 __do_sys_write fs/read_write.c:624 [inline] __se_sys_write+0x92/0xb0 fs/read_write.c:621 __ia32_sys_write+0x4a/0x70 fs/read_write.c:621 do_syscall_32_irqs_on arch/x86/entry/common.c:339 [inline] do_fast_syscall_32+0x3bf/0x6d0 arch/x86/entry/common.c:398 entry_SYSENTER_compat+0x68/0x77 arch/x86/entry/entry_64_compat.S:139 RIP: 0023:0xf7f86dd9 Code: 90 e8 0b 00 00 00 f3 90 0f ae e8 eb f9 8d 74 26 00 89 3c 24 c3 90 90 90 90 90 90 90 90 90 90 90 90 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 002b:00000000f5d810cc 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:2802 [inline] __kmalloc_node_track_caller+0xb40/0x1200 mm/slub.c:4436 __kmalloc_reserve net/core/skbuff.c:142 [inline] __alloc_skb+0x2fd/0xac0 net/core/skbuff.c:210 alloc_skb include/linux/skbuff.h:1083 [inline] alloc_skb_with_frags+0x18c/0xa70 net/core/skbuff.c:5772 sock_alloc_send_pskb+0xada/0xc60 net/core/sock.c:2265 tun_alloc_skb drivers/net/tun.c:1492 [inline] tun_get_user+0x1260/0x71e0 drivers/net/tun.c:1808 tun_chr_write_iter+0x1f2/0x360 drivers/net/tun.c:1992 call_write_iter include/linux/fs.h:1907 [inline] new_sync_write fs/read_write.c:484 [inline] __vfs_write+0xa5a/0xca0 fs/read_write.c:497 vfs_write+0x444/0x8e0 fs/read_write.c:559 ksys_write+0x267/0x450 fs/read_write.c:612 __do_sys_write fs/read_write.c:624 [inline] __se_sys_write+0x92/0xb0 fs/read_write.c:621 __ia32_sys_write+0x4a/0x70 fs/read_write.c:621 do_syscall_32_irqs_on arch/x86/entry/common.c:339 [inline] do_fast_syscall_32+0x3bf/0x6d0 arch/x86/entry/common.c:398 entry_SYSENTER_compat+0x68/0x77 arch/x86/entry/entry_64_compat.S:139 =====================================================