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KCSAN: data-race in _extract_crng / crng_reseed (2)

Status: auto-closed as invalid on 2021/02/24 01:37
Subsystems: kernel
[Documentation on labels]
First crash: 1192d, last: 1192d
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in _extract_crng / crng_reseed kernel 2 1339d 1354d 0/26 auto-closed as invalid on 2020/09/29 18:37
upstream KCSAN: data-race in _extract_crng / crng_reseed (3) kernel 1 1015d 1015d 0/26 auto-closed as invalid on 2021/09/03 03:07

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

write to 0xffffffff88bef888 of 8 bytes by task 9569 on cpu 0:
 crng_reseed+0x399/0x630 drivers/char/random.c:975
 _extract_crng+0xca/0x2b0 drivers/char/random.c:1006
 crng_reseed+0x69/0x630 drivers/char/random.c:962
 _extract_crng+0xca/0x2b0 drivers/char/random.c:1006
 extract_crng drivers/char/random.c:1026 [inline]
 _get_random_bytes+0x141/0x240 drivers/char/random.c:1562
 get_random_bytes+0x65/0x110 drivers/char/random.c:1575
 eth_random_addr include/linux/etherdevice.h:225 [inline]
 nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:520 [inline]
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:570 [inline]
 nsim_dev_trap_report_work+0x217/0x5b0 drivers/net/netdevsim/dev.c:611
 process_one_work+0x3e1/0x950 kernel/workqueue.c:2275
 worker_thread+0x635/0xb90 kernel/workqueue.c:2421
 kthread+0x1fd/0x220 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

read to 0xffffffff88bef888 of 8 bytes by task 19 on cpu 1:
 _extract_crng+0x45/0x2b0 drivers/char/random.c:1004
 crng_reseed+0x69/0x630 drivers/char/random.c:962
 _extract_crng+0xca/0x2b0 drivers/char/random.c:1006
 extract_crng drivers/char/random.c:1026 [inline]
 _get_random_bytes+0x141/0x240 drivers/char/random.c:1562
 get_random_bytes+0x65/0x110 drivers/char/random.c:1575
 eth_random_addr include/linux/etherdevice.h:225 [inline]
 nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:520 [inline]
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:570 [inline]
 nsim_dev_trap_report_work+0x217/0x5b0 drivers/net/netdevsim/dev.c:611
 process_one_work+0x3e1/0x950 kernel/workqueue.c:2275
 worker_thread+0x635/0xb90 kernel/workqueue.c:2421
 kthread+0x1fd/0x220 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 19 Comm: kworker/1:0 Not tainted 5.11.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events nsim_dev_trap_report_work
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2021/01/20 01:34 upstream 1e2a199f6ccd 63631df1 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in _extract_crng / crng_reseed
* Struck through repros no longer work on HEAD.