syzbot


KCSAN: data-race in ip6_tnl_start_xmit / ip6_tnl_start_xmit (8)

Status: auto-closed as invalid on 2022/09/02 16:35
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 135d, last: 126d
similar bugs (7):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in ip6_tnl_start_xmit / ip6_tnl_start_xmit (6) 1 266d 266d 0/24 auto-closed as invalid on 2022/04/15 20:54
upstream KCSAN: data-race in ip6_tnl_start_xmit / ip6_tnl_start_xmit (5) 9 320d 384d 0/24 auto-closed as invalid on 2022/02/20 15:36
upstream KCSAN: data-race in ip6_tnl_start_xmit / ip6_tnl_start_xmit 10 994d 1129d 0/24 auto-closed as invalid on 2020/05/22 23:22
upstream KCSAN: data-race in ip6_tnl_start_xmit / ip6_tnl_start_xmit (2) 2 865d 866d 0/24 auto-closed as invalid on 2020/08/24 20:07
upstream KCSAN: data-race in ip6_tnl_start_xmit / ip6_tnl_start_xmit (4) 1 606d 606d 0/24 auto-closed as invalid on 2021/05/17 09:21
upstream KCSAN: data-race in ip6_tnl_start_xmit / ip6_tnl_start_xmit (3) 2 765d 771d 0/24 auto-closed as invalid on 2020/12/03 02:00
upstream KCSAN: data-race in ip6_tnl_start_xmit / ip6_tnl_start_xmit (7) 1 206d 206d 0/24 auto-closed as invalid on 2022/06/14 13:17

Sample crash report:
==================================================================
BUG: KCSAN: data-race in ip6_tnl_start_xmit / ip6_tnl_start_xmit

read-write to 0xffff888135d28168 of 8 bytes by task 22103 on cpu 1:
 ip6_tnl_start_xmit+0x883/0xa90 net/ipv6/ip6_tunnel.c:1444
 __netdev_start_xmit include/linux/netdevice.h:4805 [inline]
 netdev_start_xmit include/linux/netdevice.h:4819 [inline]
 xmit_one+0xc0/0x2a0 net/core/dev.c:3590
 dev_hard_start_xmit+0x72/0x120 net/core/dev.c:3606
 __dev_queue_xmit+0x84c/0xfe0 net/core/dev.c:4255
 dev_queue_xmit include/linux/netdevice.h:2994 [inline]
 __bpf_tx_skb net/core/filter.c:2114 [inline]
 __bpf_redirect_no_mac net/core/filter.c:2139 [inline]
 __bpf_redirect+0x556/0x840 net/core/filter.c:2162
 ____bpf_clone_redirect net/core/filter.c:2429 [inline]
 bpf_clone_redirect+0x168/0x1c0 net/core/filter.c:2401
 ___bpf_prog_run+0x278/0x2da0 kernel/bpf/core.c:1852
 __bpf_prog_run512+0x70/0xa0 kernel/bpf/core.c:2077
 bpf_dispatcher_nop_func include/linux/bpf.h:869 [inline]
 __bpf_prog_run include/linux/filter.h:628 [inline]
 bpf_prog_run include/linux/filter.h:635 [inline]
 bpf_test_run+0x1eb/0x410 net/bpf/test_run.c:402
 bpf_prog_test_run_skb+0x76b/0x9f0 net/bpf/test_run.c:1155
 bpf_prog_test_run+0x22a/0x250 kernel/bpf/syscall.c:3591
 __sys_bpf+0x3c4/0x630 kernel/bpf/syscall.c:4935
 __do_sys_bpf kernel/bpf/syscall.c:5021 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5019 [inline]
 __x64_sys_bpf+0x3f/0x50 kernel/bpf/syscall.c:5019
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

read-write to 0xffff888135d28168 of 8 bytes by task 22104 on cpu 0:
 ip6_tnl_start_xmit+0x883/0xa90 net/ipv6/ip6_tunnel.c:1444
 __netdev_start_xmit include/linux/netdevice.h:4805 [inline]
 netdev_start_xmit include/linux/netdevice.h:4819 [inline]
 xmit_one+0xc0/0x2a0 net/core/dev.c:3590
 dev_hard_start_xmit+0x72/0x120 net/core/dev.c:3606
 __dev_queue_xmit+0x84c/0xfe0 net/core/dev.c:4255
 dev_queue_xmit include/linux/netdevice.h:2994 [inline]
 __bpf_tx_skb net/core/filter.c:2114 [inline]
 __bpf_redirect_no_mac net/core/filter.c:2139 [inline]
 __bpf_redirect+0x556/0x840 net/core/filter.c:2162
 ____bpf_clone_redirect net/core/filter.c:2429 [inline]
 bpf_clone_redirect+0x168/0x1c0 net/core/filter.c:2401
 ___bpf_prog_run+0x278/0x2da0 kernel/bpf/core.c:1852
 __bpf_prog_run512+0x70/0xa0 kernel/bpf/core.c:2077
 bpf_dispatcher_nop_func include/linux/bpf.h:869 [inline]
 __bpf_prog_run include/linux/filter.h:628 [inline]
 bpf_prog_run include/linux/filter.h:635 [inline]
 bpf_test_run+0x1eb/0x410 net/bpf/test_run.c:402
 bpf_prog_test_run_skb+0x76b/0x9f0 net/bpf/test_run.c:1155
 bpf_prog_test_run+0x22a/0x250 kernel/bpf/syscall.c:3591
 __sys_bpf+0x3c4/0x630 kernel/bpf/syscall.c:4935
 __do_sys_bpf kernel/bpf/syscall.c:5021 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5019 [inline]
 __x64_sys_bpf+0x3f/0x50 kernel/bpf/syscall.c:5019
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x000000000000c08a -> 0x000000000000c08c

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 22104 Comm: syz-executor.3 Not tainted 5.19.0-rc8-syzkaller-00105-g6e2c0490769e-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022
==================================================================

Crashes (2):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2022/07/29 16:27 upstream 6e2c0490769e fef302b1 .config log report info KCSAN: data-race in ip6_tnl_start_xmit / ip6_tnl_start_xmit
ci2-upstream-kcsan-gce 2022/07/21 01:04 upstream 353f7988dd84 88cb1383 .config log report info KCSAN: data-race in ip6_tnl_start_xmit / ip6_tnl_start_xmit
* Struck through repros no longer work on HEAD.