diff mbox series

blk-mq: fix possible memleak when register 'hctx' failed

Message ID 20221117022940.873959-1-yebin@huaweicloud.com
State New
Headers
Series blk-mq: fix possible memleak when register 'hctx' failed |

Commit Message

Ye Bin Nov. 17, 2022, 2:29 a.m. UTC 
  From: Ye Bin <yebin10@huawei.com>

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>
---
 block/blk-mq-sysfs.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

Comments

Ming Lei Nov. 17, 2022, 2:19 a.m. UTC | #1 
On Thu, Nov 17, 2022 at 10:29:40AM +0800, Ye Bin wrote:
> From: Ye Bin <yebin10@huawei.com>
> 
> 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>


Thanks,
Ming
Ye Bin Nov. 24, 2022, 1:44 p.m. UTC | #2 
ping...

On 2022/11/17 10:29, Ye Bin wrote:
> From: Ye Bin <yebin10@huawei.com>
>
> 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>
> ---
>   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 93997d297d42..4515288fbe35 100644
> --- a/block/blk-mq-sysfs.c
> +++ b/block/blk-mq-sysfs.c
> @@ -185,7 +185,7 @@ 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;
> @@ -197,9 +197,16 @@ 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;
>   }
>
Jens Axboe Nov. 25, 2022, 1:34 p.m. UTC | #3 
On Thu, 17 Nov 2022 10:29:40 +0800, Ye Bin wrote:
> From: Ye Bin <yebin10@huawei.com>
> 
> 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
> 
> [...]

Applied, thanks!

[1/1] blk-mq: fix possible memleak when register 'hctx' failed
      commit: 4b7a21c57b14fbcd0e1729150189e5933f5088e9

Best regards,
diff mbox series

Patch

diff --git a/block/blk-mq-sysfs.c b/block/blk-mq-sysfs.c
index 93997d297d42..4515288fbe35 100644
--- a/block/blk-mq-sysfs.c
+++ b/block/blk-mq-sysfs.c
@@ -185,7 +185,7 @@  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;
@@ -197,9 +197,16 @@  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;
 }