KMSAN: uninit-value in bpf_skb_load_helper_16

Status: closed as invalid on 2020/05/28 10:23
Subsystems: net bpf
[Documentation on labels]
First crash: 2270d, last: 2269d
▶ ▼ Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KMSAN: uninit-value in bpf_skb_load_helper_16 (2) bpf net 7 syz, C 27 2215d 2218d 0/29 closed as invalid on 2020/07/22 14:22

Sample crash report:
=====================================================
BUG: KMSAN: uninit-value in ____bpf_skb_load_helper_16 net/core/filter.c:211 [inline]
BUG: KMSAN: uninit-value in bpf_skb_load_helper_16+0xd9/0x2b0 net/core/filter.c:205
CPU: 1 PID: 8809 Comm: syz-executor988 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
 ____bpf_skb_load_helper_16 net/core/filter.c:211 [inline]
 bpf_skb_load_helper_16+0xd9/0x2b0 net/core/filter.c:205
 ___bpf_prog_run+0x214d/0x97a0 kernel/bpf/core.c:1516
 __bpf_prog_run32+0x101/0x170 kernel/bpf/core.c:1681
 bpf_dispatcher_nop_func include/linux/bpf.h:545 [inline]
 __bpf_prog_run_save_cb include/linux/filter.h:693 [inline]
 bpf_prog_run_save_cb include/linux/filter.h:707 [inline]
 sk_filter_trim_cap+0x42a/0xcc0 net/core/filter.c:119
 sk_filter include/linux/filter.h:833 [inline]
 unix_dgram_sendmsg+0x1987/0x3c30 net/unix/af_unix.c:1710
 unix_seqpacket_sendmsg+0x26c/0x2e0 net/unix/af_unix.c:2063
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg net/socket.c:672 [inline]
 kernel_sendmsg+0x433/0x440 net/socket.c:692
 sock_no_sendpage+0x235/0x300 net/core/sock.c:2763
 kernel_sendpage net/socket.c:3808 [inline]
 sock_sendpage+0x1e1/0x2c0 net/socket.c:950
 pipe_to_sendpage+0x38c/0x4c0 fs/splice.c:458
 splice_from_pipe_feed fs/splice.c:512 [inline]
 __splice_from_pipe+0x539/0xed0 fs/splice.c:636
 splice_from_pipe fs/splice.c:671 [inline]
 generic_splice_sendpage+0x1d5/0x2d0 fs/splice.c:844
 do_splice_from fs/splice.c:863 [inline]
 do_splice+0x1eae/0x2ec0 fs/splice.c:1170
 __do_sys_splice fs/splice.c:1447 [inline]
 __se_sys_splice+0x426/0x520 fs/splice.c:1427
 __x64_sys_splice+0x6e/0x90 fs/splice.c:1427
 do_syscall_64+0xb8/0x160 arch/x86/entry/common.c:297
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x4402b9
Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 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 fb 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fff817199e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000113
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 00000000004402b9
RDX: 0000000000000005 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00000000006ca018 R08: 000000000004ffe0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401b40
R13: 0000000000401bd0 R14: 0000000000000000 R15: 0000000000000000

Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:144 [inline]
 kmsan_internal_chain_origin+0xad/0x130 mm/kmsan/kmsan.c:310
 __msan_chain_origin+0x50/0x90 mm/kmsan/kmsan_instr.c:165
 ___bpf_prog_run+0x6cbe/0x97a0 kernel/bpf/core.c:1391
 __bpf_prog_run32+0x101/0x170 kernel/bpf/core.c:1681
 bpf_dispatcher_nop_func include/linux/bpf.h:545 [inline]
 __bpf_prog_run_save_cb include/linux/filter.h:693 [inline]
 bpf_prog_run_save_cb include/linux/filter.h:707 [inline]
 sk_filter_trim_cap+0x42a/0xcc0 net/core/filter.c:119
 sk_filter include/linux/filter.h:833 [inline]
 unix_dgram_sendmsg+0x1987/0x3c30 net/unix/af_unix.c:1710
 unix_seqpacket_sendmsg+0x26c/0x2e0 net/unix/af_unix.c:2063
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg net/socket.c:672 [inline]
 kernel_sendmsg+0x433/0x440 net/socket.c:692
 sock_no_sendpage+0x235/0x300 net/core/sock.c:2763
 kernel_sendpage net/socket.c:3808 [inline]
 sock_sendpage+0x1e1/0x2c0 net/socket.c:950
 pipe_to_sendpage+0x38c/0x4c0 fs/splice.c:458
 splice_from_pipe_feed fs/splice.c:512 [inline]
 __splice_from_pipe+0x539/0xed0 fs/splice.c:636
 splice_from_pipe fs/splice.c:671 [inline]
 generic_splice_sendpage+0x1d5/0x2d0 fs/splice.c:844
 do_splice_from fs/splice.c:863 [inline]
 do_splice+0x1eae/0x2ec0 fs/splice.c:1170
 __do_sys_splice fs/splice.c:1447 [inline]
 __se_sys_splice+0x426/0x520 fs/splice.c:1427
 __x64_sys_splice+0x6e/0x90 fs/splice.c:1427
 do_syscall_64+0xb8/0x160 arch/x86/entry/common.c:297
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:144 [inline]
 kmsan_internal_chain_origin+0xad/0x130 mm/kmsan/kmsan.c:310
 __msan_chain_origin+0x50/0x90 mm/kmsan/kmsan_instr.c:165
 ___bpf_prog_run+0x6c64/0x97a0 kernel/bpf/core.c:1391
 __bpf_prog_run32+0x101/0x170 kernel/bpf/core.c:1681
 bpf_dispatcher_nop_func include/linux/bpf.h:545 [inline]
 __bpf_prog_run_save_cb include/linux/filter.h:693 [inline]
 bpf_prog_run_save_cb include/linux/filter.h:707 [inline]
 sk_filter_trim_cap+0x42a/0xcc0 net/core/filter.c:119
 sk_filter include/linux/filter.h:833 [inline]
 unix_dgram_sendmsg+0x1987/0x3c30 net/unix/af_unix.c:1710
 unix_seqpacket_sendmsg+0x26c/0x2e0 net/unix/af_unix.c:2063
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg net/socket.c:672 [inline]
 kernel_sendmsg+0x433/0x440 net/socket.c:692
 sock_no_sendpage+0x235/0x300 net/core/sock.c:2763
 kernel_sendpage net/socket.c:3808 [inline]
 sock_sendpage+0x1e1/0x2c0 net/socket.c:950
 pipe_to_sendpage+0x38c/0x4c0 fs/splice.c:458
 splice_from_pipe_feed fs/splice.c:512 [inline]
 __splice_from_pipe+0x539/0xed0 fs/splice.c:636
 splice_from_pipe fs/splice.c:671 [inline]
 generic_splice_sendpage+0x1d5/0x2d0 fs/splice.c:844
 do_splice_from fs/splice.c:863 [inline]
 do_splice+0x1eae/0x2ec0 fs/splice.c:1170
 __do_sys_splice fs/splice.c:1447 [inline]
 __se_sys_splice+0x426/0x520 fs/splice.c:1427
 __x64_sys_splice+0x6e/0x90 fs/splice.c:1427
 do_syscall_64+0xb8/0x160 arch/x86/entry/common.c:297
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Local variable ----regs@__bpf_prog_run32 created at:
 __bpf_prog_run32+0x87/0x170 kernel/bpf/core.c:1681
 __bpf_prog_run32+0x87/0x170 kernel/bpf/core.c:1681
=====================================================

Crashes (24):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/05/27 04:58 https://github.com/google/kmsan.git master 94bc4cd0c2f0 9072c126 .config console log report syz C ci-upstream-kmsan-gce
2020/05/27 08:50 https://github.com/google/kmsan.git master 94bc4cd0c2f0 9072c126 .config console log report ci-upstream-kmsan-gce
2020/05/26 23:03 https://github.com/google/kmsan.git master 94bc4cd0c2f0 9072c126 .config console log report ci-upstream-kmsan-gce
2020/05/26 22:17 https://github.com/google/kmsan.git master 94bc4cd0c2f0 9072c126 .config console log report ci-upstream-kmsan-gce
2020/05/26 22:13 https://github.com/google/kmsan.git master 94bc4cd0c2f0 9072c126 .config console log report ci-upstream-kmsan-gce
2020/05/26 22:10 https://github.com/google/kmsan.git master 94bc4cd0c2f0 9072c126 .config console log report ci-upstream-kmsan-gce
2020/05/26 21:48 https://github.com/google/kmsan.git master 94bc4cd0c2f0 9072c126 .config console log report ci-upstream-kmsan-gce
2020/05/26 21:25 https://github.com/google/kmsan.git master 94bc4cd0c2f0 9072c126 .config console log report ci-upstream-kmsan-gce
2020/05/26 21:17 https://github.com/google/kmsan.git master 94bc4cd0c2f0 9072c126 .config console log report ci-upstream-kmsan-gce
2020/05/26 21:08 https://github.com/google/kmsan.git master 94bc4cd0c2f0 9072c126 .config console log report ci-upstream-kmsan-gce
2020/05/26 20:33 https://github.com/google/kmsan.git master 94bc4cd0c2f0 9072c126 .config console log report ci-upstream-kmsan-gce
2020/05/26 20:24 https://github.com/google/kmsan.git master 94bc4cd0c2f0 9072c126 .config console log report ci-upstream-kmsan-gce
2020/05/26 20:13 https://github.com/google/kmsan.git master 94bc4cd0c2f0 9072c126 .config console log report ci-upstream-kmsan-gce
2020/05/26 19:41 https://github.com/google/kmsan.git master 94bc4cd0c2f0 9072c126 .config console log report ci-upstream-kmsan-gce
2020/05/27 22:10 https://github.com/google/kmsan.git master 8b611d82b66b ec153193 .config console log report ci-upstream-kmsan-gce-386
2020/05/27 14:59 https://github.com/google/kmsan.git master 8b611d82b66b ec153193 .config console log report ci-upstream-kmsan-gce-386
2020/05/27 13:18 https://github.com/google/kmsan.git master 8b611d82b66b ec153193 .config console log report ci-upstream-kmsan-gce-386
2020/05/27 09:02 https://github.com/google/kmsan.git master 94bc4cd0c2f0 9072c126 .config console log report ci-upstream-kmsan-gce-386
2020/05/27 04:13 https://github.com/google/kmsan.git master 94bc4cd0c2f0 9072c126 .config console log report ci-upstream-kmsan-gce-386
2020/05/26 23:01 https://github.com/google/kmsan.git master 94bc4cd0c2f0 9072c126 .config console log report ci-upstream-kmsan-gce-386
2020/05/26 21:04 https://github.com/google/kmsan.git master 94bc4cd0c2f0 9072c126 .config console log report ci-upstream-kmsan-gce-386
2020/05/26 20:40 https://github.com/google/kmsan.git master 94bc4cd0c2f0 9072c126 .config console log report ci-upstream-kmsan-gce-386
2020/05/26 20:05 https://github.com/google/kmsan.git master 94bc4cd0c2f0 9072c126 .config console log report ci-upstream-kmsan-gce-386
2020/05/26 19:26 https://github.com/google/kmsan.git master 94bc4cd0c2f0 9072c126 .config console log report ci-upstream-kmsan-gce-386
* Struck through repros no longer work on HEAD.