lkml.org 
[lkml]   [2022]   [Dec]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH AUTOSEL 4.9 17/20] blk-mq: fix possible memleak when register 'hctx' failed
Date
From: Ye Bin <yebin10@huawei.com>

[ Upstream commit 4b7a21c57b14fbcd0e1729150189e5933f5088e9 ]

There's issue as follows when do fault injection test:
unreferenced object 0xffff888132a9f400 (size 512):
comm "insmod", pid 308021, jiffies 4324277909 (age 509.733s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 08 f4 a9 32 81 88 ff ff ...........2....
08 f4 a9 32 81 88 ff ff 00 00 00 00 00 00 00 00 ...2............
backtrace:
[<00000000e8952bb4>] kmalloc_node_trace+0x22/0xa0
[<00000000f9980e0f>] blk_mq_alloc_and_init_hctx+0x3f1/0x7e0
[<000000002e719efa>] blk_mq_realloc_hw_ctxs+0x1e6/0x230
[<000000004f1fda40>] blk_mq_init_allocated_queue+0x27e/0x910
[<00000000287123ec>] __blk_mq_alloc_disk+0x67/0xf0
[<00000000a2a34657>] 0xffffffffa2ad310f
[<00000000b173f718>] 0xffffffffa2af824a
[<0000000095a1dabb>] do_one_initcall+0x87/0x2a0
[<00000000f32fdf93>] do_init_module+0xdf/0x320
[<00000000cbe8541e>] load_module+0x3006/0x3390
[<0000000069ed1bdb>] __do_sys_finit_module+0x113/0x1b0
[<00000000a1a29ae8>] do_syscall_64+0x35/0x80
[<000000009cd878b0>] entry_SYSCALL_64_after_hwframe+0x46/0xb0

Fault injection context as follows:
kobject_add
blk_mq_register_hctx
blk_mq_sysfs_register
blk_register_queue
device_add_disk
null_add_dev.part.0 [null_blk]

As 'blk_mq_register_hctx' may already add some objects when failed halfway,
but there isn't do fallback, caller don't know which objects add failed.
To solve above issue just do fallback when add objects failed halfway in
'blk_mq_register_hctx'.

Signed-off-by: Ye Bin <yebin10@huawei.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20221117022940.873959-1-yebin@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
block/blk-mq-sysfs.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/block/blk-mq-sysfs.c b/block/blk-mq-sysfs.c
index 5b64d9d7d147..fc9362e0a118 100644
--- a/block/blk-mq-sysfs.c
+++ b/block/blk-mq-sysfs.c
@@ -380,7 +380,7 @@ static int blk_mq_register_hctx(struct blk_mq_hw_ctx *hctx)
{
struct request_queue *q = hctx->queue;
struct blk_mq_ctx *ctx;
- int i, ret;
+ int i, j, ret;

if (!hctx->nr_ctx)
return 0;
@@ -392,9 +392,16 @@ static int blk_mq_register_hctx(struct blk_mq_hw_ctx *hctx)
hctx_for_each_ctx(hctx, ctx, i) {
ret = kobject_add(&ctx->kobj, &hctx->kobj, "cpu%u", ctx->cpu);
if (ret)
- break;
+ goto out;
}

+ return 0;
+out:
+ hctx_for_each_ctx(hctx, ctx, j) {
+ if (j < i)
+ kobject_del(&ctx->kobj);
+ }
+ kobject_del(&hctx->kobj);
return ret;
}

--
2.35.1
\
 
 \ /
  Last update: 2022-12-18 18:14    [W:2.719 / U:0.160 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site