Hello, syzbot found the following crash on: HEAD commit: c95d0c95 kmsan: block: skip bio block merging logic for KM.. git tree: https://github.com/google/kmsan.git master console output: https://syzkaller.appspot.com/x/log.txt?x=153677bbe00000 kernel config: https://syzkaller.appspot.com/x/.config?x=7811db4cc444a7f6 dashboard link: https://syzkaller.appspot.com/bug?extid=de5579bd3a5d86b1e863 compiler: clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81) Unfortunately, I don't have any reproducer for this crash yet. IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+de5579bd3a5d86b1e863@xxxxxxxxxxxxxxxxxxxxxxxxx ===================================================== BUG: KMSAN: uninit-value in ccid_hc_rx_getsockopt net/dccp/ccids/../ccid.h:246 [inline] BUG: KMSAN: uninit-value in do_dccp_getsockopt+0x1851/0x1e10 net/dccp/proto.c:671 CPU: 1 PID: 28577 Comm: syz-executor.1 Not tainted 5.6.0-rc7-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 ccid_hc_rx_getsockopt net/dccp/ccids/../ccid.h:246 [inline] do_dccp_getsockopt+0x1851/0x1e10 net/dccp/proto.c:671 dccp_getsockopt+0xfd/0x200 net/dccp/proto.c:694 sock_common_getsockopt+0x13f/0x180 net/core/sock.c:3111 __sys_getsockopt+0x533/0x7b0 net/socket.c:2177 __do_sys_getsockopt net/socket.c:2192 [inline] __se_sys_getsockopt+0xe1/0x100 net/socket.c:2189 __x64_sys_getsockopt+0x62/0x80 net/socket.c:2189 do_syscall_64+0xb8/0x160 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45c849 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:00007f60866cdc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000037 RAX: ffffffffffffffda RBX: 00007f60866ce6d4 RCX: 000000000045c849 RDX: 00000000000000a9 RSI: 000000000000010d RDI: 0000000000000004 RBP: 000000000076bf00 R08: 00000000200000c0 R09: 0000000000000000 R10: 0000000020000140 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000174 R14: 00000000004c3f3e R15: 000000000076bf0c 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:2801 [inline] slab_alloc mm/slub.c:2810 [inline] kmem_cache_alloc+0x711/0xd70 mm/slub.c:2815 ccid_new+0x1da/0x680 net/dccp/ccid.c:148 dccp_hdlr_ccid+0x9f/0x260 net/dccp/feat.c:39 __dccp_feat_activate net/dccp/feat.c:339 [inline] dccp_feat_activate_values+0x5e9/0x1660 net/dccp/feat.c:1537 dccp_rcv_request_sent_state_process net/dccp/input.c:468 [inline] dccp_rcv_state_process+0x1a6d/0x2320 net/dccp/input.c:676 dccp_v4_do_rcv+0x221/0x330 net/dccp/ipv4.c:684 sk_backlog_rcv include/net/sock.h:963 [inline] __release_sock+0x2a3/0x5c0 net/core/sock.c:2440 release_sock+0x99/0x2a0 net/core/sock.c:2956 inet_wait_for_connect net/ipv4/af_inet.c:588 [inline] __inet_stream_connect+0xb05/0x1340 net/ipv4/af_inet.c:680 inet_stream_connect+0x101/0x180 net/ipv4/af_inet.c:719 __sys_connect_file net/socket.c:1859 [inline] __sys_connect+0x6f7/0x770 net/socket.c:1876 __do_sys_connect net/socket.c:1887 [inline] __se_sys_connect+0x8d/0xb0 net/socket.c:1884 __x64_sys_connect+0x4a/0x70 net/socket.c:1884 do_syscall_64+0xb8/0x160 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x44/0xa9 ===================================================== --- This bug is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this bug report. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
