memory leak in llc_ui_sendmsg

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: f49aa1de Merge tag 'for-5.2-rc1-tag' of git://git.kernel.o..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=117ba18aa00000
kernel config: https://syzkaller.appspot.com/x/.config?x=61dd9e15a761691d
dashboard link: https://syzkaller.appspot.com/bug?extid=31c16aa4202dace3812e
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=137f3d9ca00000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=156389f8a00000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+31c16a...@syzkaller.appspotmail.com

udit(1558395599.193:36): avc: denied { map } for pid=7045
comm="syz-executor641" path="/root/syz-executor641959542" dev="sda1"
ino=1426 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023
tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1
executing program
executing program
executing program
BUG: memory leak
unreferenced object 0xffff888116270800 (size 224):
comm "syz-executor641", pid 7047, jiffies 4294947360 (age 13.860s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 20 e1 2a 81 88 ff ff 00 40 3d 2a 81 88 ff ff . .*.....@=*....
backtrace:
[<000000004d41b4cc>] kmemleak_alloc_recursive
include/linux/kmemleak.h:55 [inline]
[<000000004d41b4cc>] slab_post_alloc_hook mm/slab.h:439 [inline]
[<000000004d41b4cc>] slab_alloc_node mm/slab.c:3269 [inline]
[<000000004d41b4cc>] kmem_cache_alloc_node+0x153/0x2a0 mm/slab.c:3579
[<00000000506a5965>] __alloc_skb+0x6e/0x210 net/core/skbuff.c:198
[<000000001ba5a161>] alloc_skb include/linux/skbuff.h:1058 [inline]
[<000000001ba5a161>] alloc_skb_with_frags+0x5f/0x250
net/core/skbuff.c:5327
[<0000000047d9c78b>] sock_alloc_send_pskb+0x269/0x2a0
net/core/sock.c:2225
[<000000003828fe54>] sock_alloc_send_skb+0x32/0x40 net/core/sock.c:2242
[<00000000e34d94f9>] llc_ui_sendmsg+0x10a/0x540 net/llc/af_llc.c:933
[<00000000de2de3fb>] sock_sendmsg_nosec net/socket.c:652 [inline]
[<00000000de2de3fb>] sock_sendmsg+0x54/0x70 net/socket.c:671
[<000000008fe16e7a>] __sys_sendto+0x148/0x1f0 net/socket.c:1964
[<000000005b17a3ac>] __do_sys_sendto net/socket.c:1976 [inline]
[<000000005b17a3ac>] __se_sys_sendto net/socket.c:1972 [inline]
[<000000005b17a3ac>] __x64_sys_sendto+0x2a/0x30 net/socket.c:1972
[<0000000094b2fa53>] do_syscall_64+0x76/0x1a0
arch/x86/entry/common.c:301
[<00000000ea5a7233>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

BUG: memory leak
unreferenced object 0xffff88812274ac00 (size 512):
comm "syz-executor641", pid 7047, jiffies 4294947360 (age 13.860s)
hex dump (first 32 bytes):
08 c2 03 00 00 00 00 00 69 63 65 73 2f 76 69 72 ........ices/vir
74 75 61 6c 2f 74 74 79 2f 74 74 79 71 37 00 41 tual/tty/ttyq7.A
backtrace:
[<000000009abfb07f>] kmemleak_alloc_recursive
include/linux/kmemleak.h:55 [inline]
[<000000009abfb07f>] slab_post_alloc_hook mm/slab.h:439 [inline]
[<000000009abfb07f>] slab_alloc_node mm/slab.c:3269 [inline]
[<000000009abfb07f>] kmem_cache_alloc_node_trace+0x15b/0x2a0
mm/slab.c:3597
[<000000001e6bdec9>] __do_kmalloc_node mm/slab.c:3619 [inline]
[<000000001e6bdec9>] __kmalloc_node_track_caller+0x38/0x50
mm/slab.c:3634
[<00000000dcf4f208>] __kmalloc_reserve.isra.0+0x40/0xb0
net/core/skbuff.c:142
[<0000000081158459>] __alloc_skb+0xa0/0x210 net/core/skbuff.c:210
[<000000001ba5a161>] alloc_skb include/linux/skbuff.h:1058 [inline]
[<000000001ba5a161>] alloc_skb_with_frags+0x5f/0x250
net/core/skbuff.c:5327
[<0000000047d9c78b>] sock_alloc_send_pskb+0x269/0x2a0
net/core/sock.c:2225
[<000000003828fe54>] sock_alloc_send_skb+0x32/0x40 net/core/sock.c:2242
[<00000000e34d94f9>] llc_ui_sendmsg+0x10a/0x540 net/llc/af_llc.c:933
[<00000000de2de3fb>] sock_sendmsg_nosec net/socket.c:652 [inline]
[<00000000de2de3fb>] sock_sendmsg+0x54/0x70 net/socket.c:671
[<000000008fe16e7a>] __sys_sendto+0x148/0x1f0 net/socket.c:1964
[<000000005b17a3ac>] __do_sys_sendto net/socket.c:1976 [inline]
[<000000005b17a3ac>] __se_sys_sendto net/socket.c:1972 [inline]
[<000000005b17a3ac>] __x64_sys_sendto+0x2a/0x30 net/socket.c:1972
[<0000000094b2fa53>] do_syscall_64+0x76/0x1a0
arch/x86/entry/common.c:301
[<00000000ea5a7233>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

executing program
executing program


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