Re: memory leak in create_ctx

From: Jakub Kicinski
Date: Sat Jun 08 2019 - 19:51:38 EST


On Sat, 08 Jun 2019 12:13:06 -0700, syzbot wrote:
> Hello,
>
> syzbot found the following crash on:
>
> HEAD commit: 79c3ba32 Merge tag 'drm-fixes-2019-06-07-1' of git://anong..
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=170e0bfea00000
> kernel config: https://syzkaller.appspot.com/x/.config?x=d5c73825cbdc7326
> dashboard link: https://syzkaller.appspot.com/bug?extid=06537213db7ba2745c4a
> compiler: gcc (GCC) 9.0.0 20181231 (experimental)
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10aa806aa00000
>
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+06537213db7ba2745c4a@xxxxxxxxxxxxxxxxxxxxxxxxx

This one creates a TCPv6 socket, puts it in repair mode, connects and
then adds a tls ULP. Apparently that leaks the entire TLS context but
I can't repro..

> IPv6: ADDRCONF(NETDEV_CHANGE): team0: link becomes ready
> 2019/06/08 14:55:51 executed programs: 15
> 2019/06/08 14:55:56 executed programs: 31
> 2019/06/08 14:56:02 executed programs: 51
> BUG: memory leak
> unreferenced object 0xffff888117ceae00 (size 512):
> comm "syz-executor.3", pid 7233, jiffies 4294949016 (age 13.640s)
> 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:
> [<00000000e6550967>] kmemleak_alloc_recursive
> include/linux/kmemleak.h:55 [inline]
> [<00000000e6550967>] slab_post_alloc_hook mm/slab.h:439 [inline]
> [<00000000e6550967>] slab_alloc mm/slab.c:3326 [inline]
> [<00000000e6550967>] kmem_cache_alloc_trace+0x13d/0x280 mm/slab.c:3553
> [<0000000014132182>] kmalloc include/linux/slab.h:547 [inline]
> [<0000000014132182>] kzalloc include/linux/slab.h:742 [inline]
> [<0000000014132182>] create_ctx+0x25/0x70 net/tls/tls_main.c:601
> [<00000000e08e1a44>] tls_init net/tls/tls_main.c:787 [inline]
> [<00000000e08e1a44>] tls_init+0x97/0x1e0 net/tls/tls_main.c:769
> [<0000000037b0c43c>] __tcp_set_ulp net/ipv4/tcp_ulp.c:126 [inline]
> [<0000000037b0c43c>] tcp_set_ulp+0xe2/0x190 net/ipv4/tcp_ulp.c:147
> [<000000007a284277>] do_tcp_setsockopt.isra.0+0x19a/0xd60
> net/ipv4/tcp.c:2784
> [<00000000f35f3415>] tcp_setsockopt+0x71/0x80 net/ipv4/tcp.c:3098
> [<00000000c840962c>] sock_common_setsockopt+0x38/0x50
> net/core/sock.c:3124
> [<0000000006b0801f>] __sys_setsockopt+0x98/0x120 net/socket.c:2072
> [<00000000a6309f52>] __do_sys_setsockopt net/socket.c:2083 [inline]
> [<00000000a6309f52>] __se_sys_setsockopt net/socket.c:2080 [inline]
> [<00000000a6309f52>] __x64_sys_setsockopt+0x26/0x30 net/socket.c:2080
> [<00000000fa555bbc>] do_syscall_64+0x76/0x1a0
> arch/x86/entry/common.c:301
> [<00000000a06d7d1a>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
>
> BUG: memory leak
> unreferenced object 0xffff88810965dc00 (size 512):
> comm "syz-executor.2", pid 7235, jiffies 4294949016 (age 13.640s)
> 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:
> [<00000000e6550967>] kmemleak_alloc_recursive
> include/linux/kmemleak.h:55 [inline]
> [<00000000e6550967>] slab_post_alloc_hook mm/slab.h:439 [inline]
> [<00000000e6550967>] slab_alloc mm/slab.c:3326 [inline]
> [<00000000e6550967>] kmem_cache_alloc_trace+0x13d/0x280 mm/slab.c:3553
> [<0000000014132182>] kmalloc include/linux/slab.h:547 [inline]
> [<0000000014132182>] kzalloc include/linux/slab.h:742 [inline]
> [<0000000014132182>] create_ctx+0x25/0x70 net/tls/tls_main.c:601
> [<00000000e08e1a44>] tls_init net/tls/tls_main.c:787 [inline]
> [<00000000e08e1a44>] tls_init+0x97/0x1e0 net/tls/tls_main.c:769
> [<0000000037b0c43c>] __tcp_set_ulp net/ipv4/tcp_ulp.c:126 [inline]
> [<0000000037b0c43c>] tcp_set_ulp+0xe2/0x190 net/ipv4/tcp_ulp.c:147
> [<000000007a284277>] do_tcp_setsockopt.isra.0+0x19a/0xd60
> net/ipv4/tcp.c:2784
> [<00000000f35f3415>] tcp_setsockopt+0x71/0x80 net/ipv4/tcp.c:3098
> [<00000000c840962c>] sock_common_setsockopt+0x38/0x50
> net/core/sock.c:3124
> [<0000000006b0801f>] __sys_setsockopt+0x98/0x120 net/socket.c:2072
> [<00000000a6309f52>] __do_sys_setsockopt net/socket.c:2083 [inline]
> [<00000000a6309f52>] __se_sys_setsockopt net/socket.c:2080 [inline]
> [<00000000a6309f52>] __x64_sys_setsockopt+0x26/0x30 net/socket.c:2080
> [<00000000fa555bbc>] do_syscall_64+0x76/0x1a0
> arch/x86/entry/common.c:301
> [<00000000a06d7d1a>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
>
> BUG: memory leak
> unreferenced object 0xffff8881207d7600 (size 512):
> comm "syz-executor.5", pid 7244, jiffies 4294949019 (age 13.610s)
> 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:
> [<00000000e6550967>] kmemleak_alloc_recursive
> include/linux/kmemleak.h:55 [inline]
> [<00000000e6550967>] slab_post_alloc_hook mm/slab.h:439 [inline]
> [<00000000e6550967>] slab_alloc mm/slab.c:3326 [inline]
> [<00000000e6550967>] kmem_cache_alloc_trace+0x13d/0x280 mm/slab.c:3553
> [<0000000014132182>] kmalloc include/linux/slab.h:547 [inline]
> [<0000000014132182>] kzalloc include/linux/slab.h:742 [inline]
> [<0000000014132182>] create_ctx+0x25/0x70 net/tls/tls_main.c:601
> [<00000000e08e1a44>] tls_init net/tls/tls_main.c:787 [inline]
> [<00000000e08e1a44>] tls_init+0x97/0x1e0 net/tls/tls_main.c:769
> [<0000000037b0c43c>] __tcp_set_ulp net/ipv4/tcp_ulp.c:126 [inline]
> [<0000000037b0c43c>] tcp_set_ulp+0xe2/0x190 net/ipv4/tcp_ulp.c:147
> [<000000007a284277>] do_tcp_setsockopt.isra.0+0x19a/0xd60
> net/ipv4/tcp.c:2784
> [<00000000f35f3415>] tcp_setsockopt+0x71/0x80 net/ipv4/tcp.c:3098
> [<00000000c840962c>] sock_common_setsockopt+0x38/0x50
> net/core/sock.c:3124
> [<0000000006b0801f>] __sys_setsockopt+0x98/0x120 net/socket.c:2072
> [<00000000a6309f52>] __do_sys_setsockopt net/socket.c:2083 [inline]
> [<00000000a6309f52>] __se_sys_setsockopt net/socket.c:2080 [inline]
> [<00000000a6309f52>] __x64_sys_setsockopt+0x26/0x30 net/socket.c:2080
> [<00000000fa555bbc>] do_syscall_64+0x76/0x1a0
> arch/x86/entry/common.c:301
> [<00000000a06d7d1a>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
>
>
>
> ---
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>
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