From: Keita Suzuki <keitasuzuki.park@sslab.ics.keio.ac.jp>
To: unlisted-recipients:; (no To-header on input)
Cc: keitasuzuki.park@sslab.ics.keio.ac.jp,
takafumi.kubota1012@sslab.ics.keio.ac.jp, naohiro.aota@wdc.com,
Jens Axboe <axboe@kernel.dk>,
linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH RESEND] block/genhd: Fix memory leak in error path of __alloc_disk_node()
Date: Wed, 11 Dec 2019 09:10:49 +0000 [thread overview]
Message-ID: <20191211091049.11080-1-keitasuzuki.park@sslab.ics.keio.ac.jp> (raw)
In-Reply-To: <20191127024057.5827-1-keitasuzuki.park@sslab.ics.keio.ac.jp>
'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
prev parent reply other threads:[~2019-12-11 9:11 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
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 [this message]
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