Description

In the Linux kernel, the following vulnerability has been resolved: locking/spinlock/debug: Fix data-race in do_raw_write_lock KCSAN reports: BUG: KCSAN: data-race in do_raw_write_lock / do_raw_write_lock write (marked) to 0xffff800009cf504c of 4 bytes by task 1102 on cpu 1: do_raw_write_lock+0x120/0x204 _raw_write_lock_irq do_exit call_usermodehelper_exec_async ret_from_fork read to 0xffff800009cf504c of 4 bytes by task 1103 on cpu 0: do_raw_write_lock+0x88/0x204 _raw_write_lock_irq do_exit call_usermodehelper_exec_async ret_from_fork value changed: 0xffffffff -> 0x00000001 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 1103 Comm: kworker/u4:1 6.1.111 Commit 1a365e822372 ("locking/spinlock/debug: Fix various data races") has adressed most of these races, but seems to be not consistent/not complete. >From do_raw_write_lock() only debug_write_lock_after() part has been converted to WRITE_ONCE(), but not debug_write_lock_before() part. Do it now.

References 8

• git.kernel.org https://git.kernel.org/stable/c/16b3590c0e1e615757dade098c8fbc0d4f040c76
• git.kernel.org https://git.kernel.org/stable/c/396a9270a7b90886be501611b13aa636f2e8c703
• git.kernel.org https://git.kernel.org/stable/c/39d2ef113416f1a4205b03fb0aa2e428d1412c77
• git.kernel.org https://git.kernel.org/stable/c/8e5b2cf10844402054b52b489b525dc30cc16908
• git.kernel.org https://git.kernel.org/stable/c/93bd23524d63deb80fb85beb2e43fafeb1043d0f
• git.kernel.org https://git.kernel.org/stable/c/b163a5e8c703201c905d6ec7920ed79d167e8442
• git.kernel.org https://git.kernel.org/stable/c/c14ecb555c3ee80eeb030a4e46d00e679537f03a
• git.kernel.org https://git.kernel.org/stable/c/c228cb699a07a5f2d596d186bc5c314c99bb8bbf

Remediation