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KCSAN: data-race in __bpf_lru_list_rotate / bpf_lru_push_free

Status: auto-closed as invalid on 2020/10/03 23:58
Subsystems: bpf
[Documentation on labels]
First crash: 1404d, last: 1332d
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in __bpf_lru_list_rotate / bpf_lru_push_free (2) bpf 32 1164d 1233d 20/26 fixed on 2021/04/09 19:46

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

write to 0xffff88809ed27cca of 1 bytes by task 17237 on cpu 0:
 __bpf_lru_node_move kernel/bpf/bpf_lru_list.c:111 [inline]
 __bpf_lru_list_rotate_active kernel/bpf/bpf_lru_list.c:151 [inline]
 __bpf_lru_list_rotate+0x328/0x7b0 kernel/bpf/bpf_lru_list.c:240
 bpf_lru_list_pop_free_to_local kernel/bpf/bpf_lru_list.c:329 [inline]
 bpf_common_lru_pop_free kernel/bpf/bpf_lru_list.c:447 [inline]
 bpf_lru_pop_free+0x7b7/0xeb0 kernel/bpf/bpf_lru_list.c:499
 prealloc_lru_pop kernel/bpf/hashtab.c:237 [inline]
 htab_lru_map_update_elem+0xb1/0x410 kernel/bpf/hashtab.c:1049
 bpf_map_update_value+0x1b4/0x320 kernel/bpf/syscall.c:197
 generic_map_update_batch+0x336/0x450 kernel/bpf/syscall.c:1342
 bpf_map_do_batch+0x286/0x2f0 kernel/bpf/syscall.c:3870
 __do_sys_bpf+0xb2a/0x9a60 kernel/bpf/syscall.c:4242
 __se_sys_bpf kernel/bpf/syscall.c:4136 [inline]
 __x64_sys_bpf+0x3d/0x50 kernel/bpf/syscall.c:4136
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88809ed27cca of 1 bytes by task 17242 on cpu 1:
 bpf_common_lru_push_free kernel/bpf/bpf_lru_list.c:507 [inline]
 bpf_lru_push_free+0xd7/0x590 kernel/bpf/bpf_lru_list.c:555
 htab_lru_map_update_elem+0x3e6/0x410 kernel/bpf/hashtab.c:1078
 bpf_map_update_value+0x1b4/0x320 kernel/bpf/syscall.c:197
 generic_map_update_batch+0x336/0x450 kernel/bpf/syscall.c:1342
 bpf_map_do_batch+0x286/0x2f0 kernel/bpf/syscall.c:3870
 __do_sys_bpf+0xb2a/0x9a60 kernel/bpf/syscall.c:4242
 __se_sys_bpf kernel/bpf/syscall.c:4136 [inline]
 __x64_sys_bpf+0x3d/0x50 kernel/bpf/syscall.c:4136
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 17242 Comm: syz-executor.2 Not tainted 5.9.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (10):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/08/29 23:50 upstream 4d41ead6ead9 d5a3ae1f .config console log report ci2-upstream-kcsan-gce
2020/08/28 07:06 upstream 15bc20c6af4c 816e0689 .config console log report ci2-upstream-kcsan-gce
2020/08/17 19:33 upstream 9123e3a74ec7 5ce13532 .config console log report ci2-upstream-kcsan-gce
2020/08/10 14:57 upstream fc80c51fd4b2 7adc7b65 .config console log report ci2-upstream-kcsan-gce
2020/08/09 07:04 upstream 06a81c1c7db9 f721e4a0 .config console log report ci2-upstream-kcsan-gce
2020/07/30 15:53 upstream 83bdc7275e62 b0947553 .config console log report ci2-upstream-kcsan-gce
2020/07/27 17:41 upstream 92ed30191993 cb93dc6a .config console log report ci2-upstream-kcsan-gce
2020/07/25 22:09 upstream 23ee3e4e5bd2 1f7cc1ca .config console log report ci2-upstream-kcsan-gce
2020/07/01 07:35 upstream 7c30b859a947 c0383ebe .config console log report ci2-upstream-kcsan-gce
2020/06/19 10:40 upstream 5e857ce6eae7 bc258b50 .config console log report ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.