syzbot


KCSAN: data-race in get_task_exe_file / ns_capable

Status: auto-closed as invalid on 2020/10/29 14:32
Subsystems: lsm
[Documentation on labels]
First crash: 1309d, last: 1309d

Sample crash report:
==================================================================
BUG: KCSAN: data-race in get_task_exe_file / ns_capable

write to 0xffff88811e63f064 of 4 bytes by task 29114 on cpu 0:
 ns_capable_common kernel/capability.c:377 [inline]
 ns_capable+0x86/0xb0 kernel/capability.c:396
 netlink_allowed net/netlink/af_netlink.c:913 [inline]
 netlink_sendmsg+0x3b3/0x7a0 net/netlink/af_netlink.c:1873
 sock_sendmsg_nosec net/socket.c:651 [inline]
 sock_sendmsg net/socket.c:671 [inline]
 ____sys_sendmsg+0x360/0x4d0 net/socket.c:2353
 ___sys_sendmsg net/socket.c:2407 [inline]
 __sys_sendmsg+0x1df/0x260 net/socket.c:2440
 __do_sys_sendmsg net/socket.c:2449 [inline]
 __se_sys_sendmsg net/socket.c:2447 [inline]
 __x64_sys_sendmsg+0x42/0x50 net/socket.c:2447
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88811e63f064 of 4 bytes by task 5070 on cpu 1:
 get_task_exe_file+0x44/0x120 kernel/fork.c:1182
 proc_exe_link+0x44/0x100 fs/proc/base.c:1721
 proc_pid_readlink+0xaf/0x230 fs/proc/base.c:1789
 vfs_readlink+0x248/0x260 fs/namei.c:4539
 do_readlinkat+0x170/0x200 fs/stat.c:431
 __do_sys_readlinkat fs/stat.c:446 [inline]
 __se_sys_readlinkat fs/stat.c:443 [inline]
 __x64_sys_readlinkat+0x4f/0x60 fs/stat.c:443
 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: 5070 Comm: systemd-journal Not tainted 5.9.0-rc6-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
2020/09/24 14:26 upstream c9c9e6a49f89 54289b08 .config console log report info ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.