Description: tcp: fix possible socket leaks in internal pacing mode
References:
 https://bugzilla.openanolis.cn/show_bug.cgi?id=61
 https://lore.kernel.org/all/20200602080425.93712-1-kerneljasonxing@gmail.com/
Notes:
 carnil> Introduced with 73a6bab5aa2a ("tcp: switch pacing timer to
 carnil> softirq based hrtimer") in 4.18-rc1. The issue only affects 4.18-
 carnil> 4.19 as 4.20-rc1 when TCP stack adopted EDT model, the issue
 carnil> was fixed along.
Bugs:
upstream: released (4.20-rc1) [864e5c090749448e879e86bec06ee396aa2c19c5]
5.10-upstream-stable: N/A "Fixed before branching point"
4.19-upstream-stable: released (4.19.228) [0a70f118475e037732557796accd0878a00fc25a]
4.9-upstream-stable: N/A "Vulnerable code introduced later"
sid: released (5.2.6-1)
5.10-bullseye-security: N/A "Fixed before branching point"
4.19-buster-security: released (4.19.232-1)
4.9-stretch-security: N/A "Vulnerable code introduced later"