Thread (7 messages) 7 messages, 4 authors, 2020-09-14

Re: memory leak in tipc_group_create_member

From: Ying Xue <hidden>
Date: 2019-08-02 12:32:29
Also in: lkml

On 8/2/19 3:44 PM, Hillf Danton wrote:
On Thu, 01 Aug 2019 19:38:06 -0700
quoted
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 <redacted>
quoted hunk ↗ jump to hunk
 
--- 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,
--
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help