syzbot


KCSAN: data-race in __htab_lru_percpu_map_update_elem / bpf_lru_pop_free (3)

Status: auto-closed as invalid on 2022/01/17 12:35
Subsystems: bpf
[Documentation on labels]
First crash: 862d, last: 862d
Similar bugs (7)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in __htab_lru_percpu_map_update_elem / bpf_lru_pop_free bpf 1 1491d 1491d 0/26 auto-closed as invalid on 2020/06/02 14:31
upstream KCSAN: data-race in __htab_lru_percpu_map_update_elem / bpf_lru_pop_free (6) bpf 1 708d 708d 0/26 auto-closed as invalid on 2022/06/21 01:00
upstream KCSAN: data-race in __htab_lru_percpu_map_update_elem / bpf_lru_pop_free (4) bpf 1 819d 819d 0/26 auto-closed as invalid on 2022/03/02 08:29
upstream KCSAN: data-race in __htab_lru_percpu_map_update_elem / bpf_lru_pop_free (8) bpf 5 304d 365d 0/26 auto-obsoleted due to no activity on 2023/07/30 11:13
upstream KCSAN: data-race in __htab_lru_percpu_map_update_elem / bpf_lru_pop_free (5) bpf 2 778d 782d 0/26 auto-closed as invalid on 2022/04/12 08:01
upstream KCSAN: data-race in __htab_lru_percpu_map_update_elem / bpf_lru_pop_free (7) bpf 14 592d 609d 0/26 auto-obsoleted due to no activity on 2022/10/14 23:50
upstream KCSAN: data-race in __htab_lru_percpu_map_update_elem / bpf_lru_pop_free (2) bpf 1 1327d 1327d 0/26 auto-closed as invalid on 2020/10/10 03:00

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

read to 0xffff88812cf08e23 of 1 bytes by task 6527 on cpu 0:
 bpf_lru_node_set_ref kernel/bpf/bpf_lru_list.h:69 [inline]
 __htab_lru_percpu_map_update_elem+0x41d/0x7e0 kernel/bpf/hashtab.c:1291
 bpf_percpu_hash_update+0x5a/0x90 kernel/bpf/hashtab.c:2216
 bpf_map_update_value+0x1dd/0x2f0 kernel/bpf/syscall.c:196
 generic_map_update_batch+0x364/0x4c0 kernel/bpf/syscall.c:1409
 bpf_map_do_batch+0x33e/0x3a0
 __sys_bpf+0x9ae/0xa3c0
 __do_sys_bpf kernel/bpf/syscall.c:4737 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:4735 [inline]
 __x64_sys_bpf+0x3f/0x50 kernel/bpf/syscall.c:4735
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

write to 0xffff88812cf08e23 of 1 bytes by task 6515 on cpu 1:
 __bpf_lru_node_move_in kernel/bpf/bpf_lru_list.c:92 [inline]
 __local_list_flush kernel/bpf/bpf_lru_list.c:300 [inline]
 bpf_lru_list_pop_free_to_local kernel/bpf/bpf_lru_list.c:327 [inline]
 bpf_common_lru_pop_free kernel/bpf/bpf_lru_list.c:447 [inline]
 bpf_lru_pop_free+0x3aa/0xef0 kernel/bpf/bpf_lru_list.c:499
 prealloc_lru_pop kernel/bpf/hashtab.c:290 [inline]
 __htab_lru_percpu_map_update_elem+0xd8/0x7e0 kernel/bpf/hashtab.c:1275
 bpf_percpu_hash_update+0x5a/0x90 kernel/bpf/hashtab.c:2216
 bpf_map_update_value+0x1dd/0x2f0 kernel/bpf/syscall.c:196
 generic_map_update_batch+0x364/0x4c0 kernel/bpf/syscall.c:1409
 bpf_map_do_batch+0x33e/0x3a0
 __sys_bpf+0x9ae/0xa3c0
 __do_sys_bpf kernel/bpf/syscall.c:4737 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:4735 [inline]
 __x64_sys_bpf+0x3f/0x50 kernel/bpf/syscall.c:4735
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x00 -> 0x01

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 6515 Comm: syz-executor.3 Not tainted 5.16.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2021/12/13 12:30 upstream 2585cf9dfaad 0304899b .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in __htab_lru_percpu_map_update_elem / bpf_lru_pop_free
* Struck through repros no longer work on HEAD.