Re: memory leak in tipc_group_create_member

Ying Xue
2019-08-02T12:32:29Z

On 8/2/19 3:44 PM, Hillf Danton wrote:
>
> On Thu, 01 Aug 2019 19:38:06 -0700
>> Hello,
>>
>> syzbot found the following crash on:
>>
>> HEAD commit: a9815a4f Merge branch 'x86-urgent-for-linus' of git://git...
>> git tree: upstream
>> console output: https://syzkaller.appspot.com/x/log.txt?x=12a6dbf0600000
>> kernel config: https://syzkaller.appspot.com/x/.config?x=37c48fb52e3789e6
>> dashboard link: https://syzkaller.appspot.com/bug?extid=f95d90c454864b3b5bc9
>> compiler: gcc (GCC) 9.0.0 20181231 (experimental)
>> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=13be3ecc600000
>> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11c992b4600000
>>
>> IMPORTANT: if you fix the bug, please add the following tag to the commit:
>> Reported-by: syzbot+f95d90c454864b3b5bc9@syzkaller.appspotmail.com
>>
>> executing program
>> BUG: memory leak
>> unreferenced object 0xffff888122bca200 (size 128):
>> comm "syz-executor232", pid 7065, jiffies 4294943817 (age 8.880s)
>> 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 18 a2 bc 22 81 88 ff ff ..........."....
>> backtrace:
>> [<000000005bada299>] kmemleak_alloc_recursive include/linux/kmemleak.h:43 [inline]
>> [<000000005bada299>] slab_post_alloc_hook mm/slab.h:522 [inline]
>> [<000000005bada299>] slab_alloc mm/slab.c:3319 [inline]
>> [<000000005bada299>] kmem_cache_alloc_trace+0x145/0x2c0 mm/slab.c:3548
>> [<00000000e7bcdc9f>] kmalloc include/linux/slab.h:552 [inline]
>> [<00000000e7bcdc9f>] kzalloc include/linux/slab.h:748 [inline]
>> [<00000000e7bcdc9f>] tipc_group_create_member+0x3c/0x190 net/tipc/group.c:306
>> [<0000000005f56f40>] tipc_group_add_member+0x34/0x40 net/tipc/group.c:327
>> [<0000000044406683>] tipc_nametbl_build_group+0x9b/0xf0 net/tipc/name_table.c:600
>> [<000000009f71e803>] tipc_sk_join net/tipc/socket.c:2901 [inline]
>> [<000000009f71e803>] tipc_setsockopt+0x170/0x490 net/tipc/socket.c:3006
>> [<000000007f61cbc2>] __sys_setsockopt+0x10f/0x220 net/socket.c:2084
>> [<00000000cc630372>] __do_sys_setsockopt net/socket.c:2100 [inline]
>> [<00000000cc630372>] __se_sys_setsockopt net/socket.c:2097 [inline]
>> [<00000000cc630372>] __x64_sys_setsockopt+0x26/0x30 net/socket.c:2097
>> [<00000000ec30be33>] do_syscall_64+0x76/0x1a0 arch/x86/entry/common.c:296
>> [<00000000271be3e6>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
>>

Acked-by: Ying Xue <ying.xue@windriver.com>

>
> --- a/net/tipc/group.c
> +++ b/net/tipc/group.c
> @@ -273,7 +273,7 @@ static struct tipc_member *tipc_group_fi
> return NULL;
> }
>
> -static void tipc_group_add_to_tree(struct tipc_group *grp,
> +static struct tipc_member *tipc_group_add_to_tree(struct tipc_group *grp,
> struct tipc_member *m)
> {
> u64 nkey, key = (u64)m->node << 32 | m->port;
> @@ -282,7 +282,6 @@ static void tipc_group_add_to_tree(struc
>
> n = &grp->members.rb_node;
> while (*n) {
> - tmp = container_of(*n, struct tipc_member, tree_node);
> parent = *n;
> tmp = container_of(parent, struct tipc_member, tree_node);
> nkey = (u64)tmp->node << 32 | tmp->port;
> @@ -291,17 +290,18 @@ static void tipc_group_add_to_tree(struc
> else if (key > nkey)
> n = &(*n)->rb_right;
> else
> - return;
> + return tmp;
> }
> rb_link_node(&m->tree_node, parent, n);
> rb_insert_color(&m->tree_node, &grp->members);
> + return m;
> }
>
> static struct tipc_member *tipc_group_create_member(struct tipc_group *grp,
> u32 node, u32 port,
> u32 instance, int state)
> {
> - struct tipc_member *m;
> + struct tipc_member *m, *n;
>
> m = kzalloc(sizeof(*m), GFP_ATOMIC);
> if (!m)
> @@ -315,10 +315,14 @@ static struct tipc_member *tipc_group_cr
> m->instance = instance;
> m->bc_acked = grp->bc_snd_nxt - 1;
> grp->member_cnt++;
> - tipc_group_add_to_tree(grp, m);
> - tipc_nlist_add(&grp->dests, m->node);
> - m->state = state;
> - return m;
> + n = tipc_group_add_to_tree(grp, m);
> + if (n == m) {
> + tipc_nlist_add(&grp->dests, m->node);
> + m->state = state;
> + } else {
> + kfree(m);
> + }
> + return n;
> }
>
> void tipc_group_add_member(struct tipc_group *grp, u32 node,
> --
>
>