===================================================== BUG: KMSAN: uninit-value in can_receive+0x23c/0x5e0 net/can/af_can.c:650 CPU: 1 PID: 22853 Comm: syz-executor.4 Not tainted 5.5.0-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+0x1c9/0x220 lib/dump_stack.c:118 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:118 __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:215 can_receive+0x23c/0x5e0 net/can/af_can.c:650 canfd_rcv+0x188/0x3a0 net/can/af_can.c:703 __netif_receive_skb_one_core net/core/dev.c:5150 [inline] __netif_receive_skb net/core/dev.c:5264 [inline] process_backlog+0x12e1/0x1410 net/core/dev.c:6095 napi_poll net/core/dev.c:6532 [inline] net_rx_action+0x786/0x1ab0 net/core/dev.c:6600 __do_softirq+0x311/0x83d kernel/softirq.c:293 do_softirq_own_stack+0x49/0x80 arch/x86/entry/entry_64.S:1091 do_softirq kernel/softirq.c:338 [inline] __local_bh_enable_ip+0x184/0x1d0 kernel/softirq.c:190 local_bh_enable+0x36/0x40 include/linux/bottom_half.h:32 rcu_read_unlock_bh include/linux/rcupdate.h:706 [inline] __dev_queue_xmit+0x3c75/0x4220 net/core/dev.c:4040 dev_queue_xmit+0x4b/0x60 net/core/dev.c:4046 packet_snd net/packet/af_packet.c:2966 [inline] packet_sendmsg+0x8436/0x92f0 net/packet/af_packet.c:2991 sock_sendmsg_nosec net/socket.c:639 [inline] sock_sendmsg net/socket.c:659 [inline] sock_write_iter+0x6bc/0x6d0 net/socket.c:991 call_write_iter include/linux/fs.h:1902 [inline] new_sync_write fs/read_write.c:483 [inline] __vfs_write+0xa5a/0xca0 fs/read_write.c:496 vfs_write+0x44a/0x8f0 fs/read_write.c:558 ksys_write+0x267/0x450 fs/read_write.c:611 __do_sys_write fs/read_write.c:623 [inline] __se_sys_write+0x92/0xb0 fs/read_write.c:620 __x64_sys_write+0x4a/0x70 fs/read_write.c:620 do_syscall_64+0xb8/0x160 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45b349 Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f811a443c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f811a4446d4 RCX: 000000000045b349 RDX: 0000000000000048 RSI: 0000000020000440 RDI: 0000000000000005 RBP: 000000000075c070 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000ccd R14: 00000000004cdb2c R15: 000000000075c07c 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:82 slab_alloc_node mm/slub.c:2774 [inline] __kmalloc_node_track_caller+0xb40/0x1200 mm/slub.c:4382 __kmalloc_reserve net/core/skbuff.c:141 [inline] __alloc_skb+0x2fd/0xac0 net/core/skbuff.c:209 alloc_skb include/linux/skbuff.h:1049 [inline] alloc_skb_with_frags+0x18c/0xa70 net/core/skbuff.c:5664 sock_alloc_send_pskb+0xada/0xc60 net/core/sock.c:2242 packet_alloc_skb net/packet/af_packet.c:2814 [inline] packet_snd net/packet/af_packet.c:2909 [inline] packet_sendmsg+0x656e/0x92f0 net/packet/af_packet.c:2991 sock_sendmsg_nosec net/socket.c:639 [inline] sock_sendmsg net/socket.c:659 [inline] sock_write_iter+0x6bc/0x6d0 net/socket.c:991 call_write_iter include/linux/fs.h:1902 [inline] new_sync_write fs/read_write.c:483 [inline] __vfs_write+0xa5a/0xca0 fs/read_write.c:496 vfs_write+0x44a/0x8f0 fs/read_write.c:558 ksys_write+0x267/0x450 fs/read_write.c:611 __do_sys_write fs/read_write.c:623 [inline] __se_sys_write+0x92/0xb0 fs/read_write.c:620 __x64_sys_write+0x4a/0x70 fs/read_write.c:620 do_syscall_64+0xb8/0x160 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x44/0xa9 =====================================================