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KCSAN: data-race in __dev_change_flags / tun_get_user

Status: auto-obsoleted due to no activity on 2023/02/07 12:27
Subsystems: net
[Documentation on labels]
First crash: 763d, last: 763d
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in __dev_change_flags / tun_get_user (2) net 2 509d 519d 0/28 auto-obsoleted due to no activity on 2023/11/06 14:06

Sample crash report:
==================================================================
BUG: KCSAN: data-race in __dev_change_flags / tun_get_user

read-write to 0xffff8881458340c0 of 4 bytes by task 26863 on cpu 0:
 __dev_change_flags+0x9e/0x3f0 net/core/dev.c:8504
 dev_change_flags+0x55/0xc0 net/core/dev.c:8602
 devinet_ioctl+0x539/0xe40 net/ipv4/devinet.c:1147
 inet_ioctl+0x215/0x2b0 net/ipv4/af_inet.c:979
 packet_ioctl+0x12a/0x180 net/packet/af_packet.c:4230
 sock_do_ioctl+0x7d/0x250 net/socket.c:1169
 sock_ioctl+0x343/0x570 net/socket.c:1286
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0xcb/0x140 fs/ioctl.c:856
 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffff8881458340c0 of 4 bytes by task 26864 on cpu 1:
 tun_get_user+0xf84/0x1400 drivers/net/tun.c:1933
 tun_chr_write_iter+0x18a/0x240 drivers/net/tun.c:2029
 call_write_iter include/linux/fs.h:2186 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x468/0x760 fs/read_write.c:584
 ksys_write+0xe8/0x1a0 fs/read_write.c:637
 __do_sys_write fs/read_write.c:649 [inline]
 __se_sys_write fs/read_write.c:646 [inline]
 __x64_sys_write+0x3e/0x50 fs/read_write.c:646
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x00001002 -> 0x00008002

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 26864 Comm: syz-executor.5 Tainted: G        W          6.2.0-rc1-syzkaller-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2022/12/27 12:09 upstream 1b929c02afd3 9da18ae8 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in __dev_change_flags / tun_get_user
* Struck through repros no longer work on HEAD.