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KCSAN: data-race in __bpf_lru_list_shrink / __htab_lru_percpu_map_update_elem

Status: closed as invalid on 2020/06/18 14:24
Subsystems: bpf
[Documentation on labels]
First crash: 1493d, last: 1426d
Similar bugs (6)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in __bpf_lru_list_shrink / __htab_lru_percpu_map_update_elem (6) bpf 25 594d 657d 0/26 auto-obsoleted due to no activity on 2022/10/14 12:43
upstream KCSAN: data-race in __bpf_lru_list_shrink / __htab_lru_percpu_map_update_elem (5) bpf 39 695d 779d 0/26 auto-closed as invalid on 2022/07/05 10:02
upstream KCSAN: data-race in __bpf_lru_list_shrink / __htab_lru_percpu_map_update_elem (3) bpf 1 1223d 1223d 0/26 auto-closed as invalid on 2021/01/23 10:19
upstream KCSAN: data-race in __bpf_lru_list_shrink / __htab_lru_percpu_map_update_elem (4) bpf 3 856d 865d 0/26 auto-closed as invalid on 2022/01/25 13:08
upstream KCSAN: data-race in __bpf_lru_list_shrink / __htab_lru_percpu_map_update_elem (2) bpf 11 1296d 1405d 0/26 auto-closed as invalid on 2020/11/11 15:25
upstream KCSAN: data-race in __bpf_lru_list_shrink / __htab_lru_percpu_map_update_elem (7) bpf 5 309d 360d 0/26 auto-obsoleted due to no activity on 2023/07/26 07:54

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

write to 0xffff888065abca23 of 1 bytes by task 16815 on cpu 1:
 bpf_lru_node_set_ref kernel/bpf/bpf_lru_list.h:70 [inline]
 __htab_lru_percpu_map_update_elem+0x40d/0x630 kernel/bpf/hashtab.c:1174
 bpf_percpu_hash_update+0x9e/0xb0 kernel/bpf/hashtab.c:1707
 bpf_map_update_value.isra.0+0x25b/0x420 kernel/bpf/syscall.c:178
 generic_map_update_batch+0x273/0x3c0 kernel/bpf/syscall.c:1326
 bpf_map_do_batch+0x194/0x3a0 kernel/bpf/syscall.c:3556
 __do_sys_bpf+0x1cca/0x3100 kernel/bpf/syscall.c:3767
 __se_sys_bpf kernel/bpf/syscall.c:3661 [inline]
 __x64_sys_bpf+0x47/0x60 kernel/bpf/syscall.c:3661
 do_syscall_64+0xc7/0x3b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff888065abca23 of 1 bytes by task 16809 on cpu 0:
 __bpf_lru_list_shrink_inactive kernel/bpf/bpf_lru_list.c:218 [inline]
 __bpf_lru_list_shrink+0x136/0x2f0 kernel/bpf/bpf_lru_list.c:266
 bpf_lru_list_pop_free_to_local kernel/bpf/bpf_lru_list.c:340 [inline]
 bpf_common_lru_pop_free kernel/bpf/bpf_lru_list.c:447 [inline]
 bpf_lru_pop_free+0x51b/0xa30 kernel/bpf/bpf_lru_list.c:499
 prealloc_lru_pop+0x30/0x70 kernel/bpf/hashtab.c:237
 __htab_lru_percpu_map_update_elem+0x37a/0x630 kernel/bpf/hashtab.c:1160
 bpf_percpu_hash_update+0x9e/0xb0 kernel/bpf/hashtab.c:1707
 bpf_map_update_value.isra.0+0x25b/0x420 kernel/bpf/syscall.c:178
 generic_map_update_batch+0x273/0x3c0 kernel/bpf/syscall.c:1326
 bpf_map_do_batch+0x194/0x3a0 kernel/bpf/syscall.c:3556
 __do_sys_bpf+0x1cca/0x3100 kernel/bpf/syscall.c:3767
 __se_sys_bpf kernel/bpf/syscall.c:3661 [inline]
 __x64_sys_bpf+0x47/0x60 kernel/bpf/syscall.c:3661
 do_syscall_64+0xc7/0x3b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 16809 Comm: syz-executor.3 Not tainted 5.7.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/05/29 17:20 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 bed08304 .config console log report ci2-upstream-kcsan-gce
2020/04/23 10:47 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 2e44d63e .config console log report ci2-upstream-kcsan-gce
2020/03/24 12:43 https://github.com/google/ktsan.git kcsan 40959e34d670 33e14df3 .config console log report ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.