Description: perf_trace_lock_acquire use-after-free
References:
 https://bugzilla.kernel.org/show_bug.cgi?id=205705
Notes:
 carnil> Introduced in 5.0-rc1 with 16306a61d3b7 ("fs/locks: always
 carnil> delete_block after waiting.")
 carnil> Original commit 6d390e4b5d48 (locks: fix a potential use-after-
 carnil> free problem when wakeup a waiter) caused a performance impact,
 carnil> and needed a followup dcf23ac3e846 ("locks: reinstate
 carnil> locks_delete_block optimization") in 5.6-rc7.
Bugs:
upstream: released (5.6-rc5) [6d390e4b5d48ec03bb87e63cf0a2bff5f4e116da]
4.19-upstream-stable: N/A "Vulnerable code not present"
4.9-upstream-stable: N/A "Vulnerable code not present"
3.16-upstream-stable: N/A "Vulnerable code not present"
sid: released (5.5.13-1)
4.19-buster-security: N/A "Vulnerable code not present"
4.9-stretch-security: N/A "Vulnerable code not present"
3.16-jessie-security: N/A "Vulnerable code not present"