memory leak in tcp_cdg_init

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 36bbbd0e Merge branch 'rcu/urgent' of git://git.kernel.org..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=16ef4dfb500000
kernel config: https://syzkaller.appspot.com/x/.config?x=b991a69440391446
dashboard link: https://syzkaller.appspot.com/bug?extid=f1e24a0594d4e3a895d3
compiler: gcc (GCC) 10.1.0-syz 20200507
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=13e1bb2b500000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+f1e24a...@syzkaller.appspotmail.com

2021/01/05 17:50:00 executed programs: 127
2021/01/05 17:50:06 executed programs: 146
2021/01/05 17:50:12 executed programs: 157
2021/01/05 17:50:19 executed programs: 175
BUG: memory leak
unreferenced object 0xffff888125940080 (size 64):
comm "syz-executor.1", pid 11113, jiffies 4294986279 (age 14.750s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<00000000bf291225>] kmalloc_array include/linux/slab.h:592 [inline]
[<00000000bf291225>] kcalloc include/linux/slab.h:621 [inline]
[<00000000bf291225>] tcp_cdg_init+0x37/0x60 net/ipv4/tcp_cdg.c:380
[<00000000f991e122>] tcp_init_congestion_control+0x31/0x160 net/ipv4/tcp_cong.c:183
[<000000009761f0eb>] tcp_reinit_congestion_control net/ipv4/tcp_cong.c:207 [inline]
[<000000009761f0eb>] tcp_set_congestion_control+0x35e/0x380 net/ipv4/tcp_cong.c:377
[<00000000825a01e7>] do_tcp_setsockopt net/ipv4/tcp.c:3319 [inline]
[<00000000825a01e7>] tcp_setsockopt+0x3fc/0x13f0 net/ipv4/tcp.c:3599
[<0000000009f41711>] __sys_setsockopt+0x1b0/0x360 net/socket.c:2115
[<000000008873566c>] __do_sys_setsockopt net/socket.c:2126 [inline]
[<000000008873566c>] __se_sys_setsockopt net/socket.c:2123 [inline]
[<000000008873566c>] __x64_sys_setsockopt+0x22/0x30 net/socket.c:2123
[<0000000048fbe902>] do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
[<00000000b377d397>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

BUG: memory leak
unreferenced object 0xffff888125940880 (size 64):
comm "syz-executor.4", pid 11115, jiffies 4294986279 (age 14.750s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<00000000bf291225>] kmalloc_array include/linux/slab.h:592 [inline]
[<00000000bf291225>] kcalloc include/linux/slab.h:621 [inline]
[<00000000bf291225>] tcp_cdg_init+0x37/0x60 net/ipv4/tcp_cdg.c:380
[<00000000f991e122>] tcp_init_congestion_control+0x31/0x160 net/ipv4/tcp_cong.c:183
[<000000009761f0eb>] tcp_reinit_congestion_control net/ipv4/tcp_cong.c:207 [inline]
[<000000009761f0eb>] tcp_set_congestion_control+0x35e/0x380 net/ipv4/tcp_cong.c:377
[<00000000825a01e7>] do_tcp_setsockopt net/ipv4/tcp.c:3319 [inline]
[<00000000825a01e7>] tcp_setsockopt+0x3fc/0x13f0 net/ipv4/tcp.c:3599
[<0000000009f41711>] __sys_setsockopt+0x1b0/0x360 net/socket.c:2115
[<000000008873566c>] __do_sys_setsockopt net/socket.c:2126 [inline]
[<000000008873566c>] __se_sys_setsockopt net/socket.c:2123 [inline]
[<000000008873566c>] __x64_sys_setsockopt+0x22/0x30 net/socket.c:2123
[<0000000048fbe902>] do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
[<00000000b377d397>] entry_SYSCALL_64_after_hwframe+0x44/0xa9



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