* [PATCH] block/genhd: Fix memory leak in error path of __alloc_disk_node()
@ 2019-11-27 2:40 Keita Suzuki
2019-12-04 9:56 ` Naohiro Aota
2019-12-11 9:10 ` [PATCH RESEND] " Keita Suzuki
0 siblings, 2 replies; 3+ messages in thread
From: Keita Suzuki @ 2019-11-27 2:40 UTC (permalink / raw)
To: Jens Axboe
Cc: linux-block, linux-kernel, keitasuzuki.park, takafumi.kubota1012
'disk->part_tbl' is malloced in disk_expand_part_tbl() and should be
freed before leaving from the error handling cases. However, current code
does not free this, causing a memory leak. Add disk_replace_part_tbl()
before freeing 'disk'.
I have tested this by randomly causing failures to the target code,
and verified on kmemleak that this memory leak does occur.
unreferenced object 0xffff888006dad500 (size 64):
comm "systemd-udevd", pid 116, jiffies 4294895558 (age 121.716s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<00000000eec79bf3>] disk_expand_part_tbl+0xab/0x170
[<00000000624e7d03>] __alloc_disk_node+0xb1/0x1c0
[<00000000ca3f4185>] 0xffffffffc01b8584
[<000000006f88a6ee>] do_one_initcall+0x8b/0x2a4
[<0000000016058199>] do_init_module+0xfd/0x380
[<00000000b6fde336>] load_module+0x3fae/0x4240
[<00000000c523d013>] __do_sys_finit_module+0x11a/0x1b0
[<00000000f07bba26>] do_syscall_64+0x6d/0x1e0
[<00000000979467fd>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
Signed-off-by: Keita Suzuki <keitasuzuki.park@sslab.ics.keio.ac.jp>
---
block/genhd.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/block/genhd.c b/block/genhd.c
index ff6268970ddc..8c4b63d7f507 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -1504,6 +1504,7 @@ struct gendisk *__alloc_disk_node(int minors, int node_id)
*/
seqcount_init(&disk->part0.nr_sects_seq);
if (hd_ref_init(&disk->part0)) {
+ disk_replace_part_tbl(disk, NULL);
hd_free_part(&disk->part0);
kfree(disk);
return NULL;
--
2.17.1
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH] block/genhd: Fix memory leak in error path of __alloc_disk_node()
2019-11-27 2:40 [PATCH] block/genhd: Fix memory leak in error path of __alloc_disk_node() Keita Suzuki
@ 2019-12-04 9:56 ` Naohiro Aota
2019-12-11 9:10 ` [PATCH RESEND] " Keita Suzuki
1 sibling, 0 replies; 3+ messages in thread
From: Naohiro Aota @ 2019-12-04 9:56 UTC (permalink / raw)
To: Keita Suzuki; +Cc: Jens Axboe, linux-block, linux-kernel, takafumi.kubota1012
Looks good,
Reviewed-by: Naohiro Aota <naohiro.aota@wdc.com>
I think you can also add:
Fixes: 6c71013ecb7e ("block: partition: convert percpu ref")
On Wed, Nov 27, 2019 at 02:40:57AM +0000, Keita Suzuki wrote:
>'disk->part_tbl' is malloced in disk_expand_part_tbl() and should be
>freed before leaving from the error handling cases. However, current code
>does not free this, causing a memory leak. Add disk_replace_part_tbl()
>before freeing 'disk'.
>
>I have tested this by randomly causing failures to the target code,
>and verified on kmemleak that this memory leak does occur.
>
>unreferenced object 0xffff888006dad500 (size 64):
> comm "systemd-udevd", pid 116, jiffies 4294895558 (age 121.716s)
> hex dump (first 32 bytes):
> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
> 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
> backtrace:
> [<00000000eec79bf3>] disk_expand_part_tbl+0xab/0x170
> [<00000000624e7d03>] __alloc_disk_node+0xb1/0x1c0
> [<00000000ca3f4185>] 0xffffffffc01b8584
> [<000000006f88a6ee>] do_one_initcall+0x8b/0x2a4
> [<0000000016058199>] do_init_module+0xfd/0x380
> [<00000000b6fde336>] load_module+0x3fae/0x4240
> [<00000000c523d013>] __do_sys_finit_module+0x11a/0x1b0
> [<00000000f07bba26>] do_syscall_64+0x6d/0x1e0
> [<00000000979467fd>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
>
>Signed-off-by: Keita Suzuki <keitasuzuki.park@sslab.ics.keio.ac.jp>
>---
> block/genhd.c | 1 +
> 1 file changed, 1 insertion(+)
>
>diff --git a/block/genhd.c b/block/genhd.c
>index ff6268970ddc..8c4b63d7f507 100644
>--- a/block/genhd.c
>+++ b/block/genhd.c
>@@ -1504,6 +1504,7 @@ struct gendisk *__alloc_disk_node(int minors, int node_id)
> */
> seqcount_init(&disk->part0.nr_sects_seq);
> if (hd_ref_init(&disk->part0)) {
>+ disk_replace_part_tbl(disk, NULL);
> hd_free_part(&disk->part0);
> kfree(disk);
> return NULL;
>--
>2.17.1
>
^ permalink raw reply [flat|nested] 3+ messages in thread* [PATCH RESEND] block/genhd: Fix memory leak in error path of __alloc_disk_node()
2019-11-27 2:40 [PATCH] block/genhd: Fix memory leak in error path of __alloc_disk_node() Keita Suzuki
2019-12-04 9:56 ` Naohiro Aota
@ 2019-12-11 9:10 ` Keita Suzuki
1 sibling, 0 replies; 3+ messages in thread
From: Keita Suzuki @ 2019-12-11 9:10 UTC (permalink / raw)
Cc: keitasuzuki.park, takafumi.kubota1012, naohiro.aota, Jens Axboe,
linux-block, linux-kernel
'disk->part_tbl' is malloced in disk_expand_part_tbl() and should be
freed before leaving from the error handling cases. However, current code
does not free this, causing a memory leak. Add disk_replace_part_tbl()
before freeing 'disk'.
I have tested this by randomly causing failures to the target code,
and verified on kmemleak that this memory leak does occur.
unreferenced object 0xffff888006dad500 (size 64):
comm "systemd-udevd", pid 116, jiffies 4294895558 (age 121.716s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<00000000eec79bf3>] disk_expand_part_tbl+0xab/0x170
[<00000000624e7d03>] __alloc_disk_node+0xb1/0x1c0
[<00000000ca3f4185>] 0xffffffffc01b8584
[<000000006f88a6ee>] do_one_initcall+0x8b/0x2a4
[<0000000016058199>] do_init_module+0xfd/0x380
[<00000000b6fde336>] load_module+0x3fae/0x4240
[<00000000c523d013>] __do_sys_finit_module+0x11a/0x1b0
[<00000000f07bba26>] do_syscall_64+0x6d/0x1e0
[<00000000979467fd>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
Fixes: 6c71013ecb7e ("block: partition: convert percpu ref")
Signed-off-by: Keita Suzuki <keitasuzuki.park@sslab.ics.keio.ac.jp>
Reviewed-by: Naohiro Aota <naohiro.aota@wdc.com>
---
block/genhd.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/block/genhd.c b/block/genhd.c
index ff6268970ddc..8c4b63d7f507 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -1504,6 +1504,7 @@ struct gendisk *__alloc_disk_node(int minors, int node_id)
*/
seqcount_init(&disk->part0.nr_sects_seq);
if (hd_ref_init(&disk->part0)) {
+ disk_replace_part_tbl(disk, NULL);
hd_free_part(&disk->part0);
kfree(disk);
return NULL;
--
2.17.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
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2019-11-27 2:40 [PATCH] block/genhd: Fix memory leak in error path of __alloc_disk_node() Keita Suzuki
2019-12-04 9:56 ` Naohiro Aota
2019-12-11 9:10 ` [PATCH RESEND] " Keita Suzuki
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