From: Shakeel Butt <shakeelb@xxxxxxxxxx>
Subject: mm/list_lru.c: fix memory leak in __memcg_init_list_lru_node
Syzbot reported following memory leak:
ffffffffda RBX: 0000000000000003 RCX: 0000000000441f79
BUG: memory leak
unreferenced object 0xffff888114f26040 (size 32):
comm "syz-executor626", pid 7056, jiffies 4294948701 (age 39.410s)
hex dump (first 32 bytes):
40 60 f2 14 81 88 ff ff 40 60 f2 14 81 88 ff ff @`......@`......
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<0000000018f36b56>] kmemleak_alloc_recursive include/linux/kmemleak.h:55 [inline]
[<0000000018f36b56>] slab_post_alloc_hook mm/slab.h:439 [inline]
[<0000000018f36b56>] slab_alloc mm/slab.c:3326 [inline]
[<0000000018f36b56>] kmem_cache_alloc_trace+0x13d/0x280 mm/slab.c:3553
[<0000000055b9a1a5>] kmalloc include/linux/slab.h:547 [inline]
[<0000000055b9a1a5>] __memcg_init_list_lru_node+0x58/0xf0 mm/list_lru.c:352
[<000000001356631d>] memcg_init_list_lru_node mm/list_lru.c:375 [inline]
[<000000001356631d>] memcg_init_list_lru mm/list_lru.c:459 [inline]
[<000000001356631d>] __list_lru_init+0x193/0x2a0 mm/list_lru.c:626
[<00000000ce062da3>] alloc_super+0x2e0/0x310 fs/super.c:269
[<000000009023adcf>] sget_userns+0x94/0x2a0 fs/super.c:609
[<0000000052182cd8>] sget+0x8d/0xb0 fs/super.c:660
[<0000000006c24238>] mount_nodev+0x31/0xb0 fs/super.c:1387
[<0000000006016a76>] fuse_mount+0x2d/0x40 fs/fuse/inode.c:1236
[<000000009a61ec1d>] legacy_get_tree+0x27/0x80 fs/fs_context.c:661
[<0000000096cd9ef8>] vfs_get_tree+0x2e/0x120 fs/super.c:1476
[<000000005b8f472d>] do_new_mount fs/namespace.c:2790 [inline]
[<000000005b8f472d>] do_mount+0x932/0xc50 fs/namespace.c:3110
[<00000000afb009b4>] ksys_mount+0xab/0x120 fs/namespace.c:3319
[<0000000018f8c8ee>] __do_sys_mount fs/namespace.c:3333 [inline]
[<0000000018f8c8ee>] __se_sys_mount fs/namespace.c:3330 [inline]
[<0000000018f8c8ee>] __x64_sys_mount+0x26/0x30 fs/namespace.c:3330
[<00000000f42066da>] do_syscall_64+0x76/0x1a0 arch/x86/entry/common.c:301
[<0000000043d74ca0>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
This is a simple off by one bug on the error path.
Link: http://lkml.kernel.org/r/20190528043202.99980-1-shakeelb@xxxxxxxxxx
Fixes: 60d3fd32a7a9 ("list_lru: introduce per-memcg lists")
Reported-by: syzbot+f90a420dfe2b1b03cb2c@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Shakeel Butt <shakeelb@xxxxxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
Reviewed-by: Kirill Tkhai <ktkhai@xxxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx> [4.0+]
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/list_lru.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/mm/list_lru.c~list_lru-fix-memory-leak-in-__memcg_init_list_lru_node
+++ a/mm/list_lru.c
@@ -354,7 +354,7 @@ static int __memcg_init_list_lru_node(st
}
return 0;
fail:
- __memcg_destroy_list_lru_node(memcg_lrus, begin, i - 1);
+ __memcg_destroy_list_lru_node(memcg_lrus, begin, i);
return -ENOMEM;
}
_
