* [PATCH v1] mm: slub: fix the leak of alloc/free traces debugfs interface
@ 2021-06-18 12:37 Faiyaz Mohammed
2021-06-18 13:15 ` Andy Shevchenko
0 siblings, 1 reply; 3+ messages in thread
From: Faiyaz Mohammed @ 2021-06-18 12:37 UTC (permalink / raw)
To: cl, penberg, rientjes, iamjoonsoo.kim, akpm, vbabka, linux-mm,
linux-kernel, greg, glittao, andy.shevchenko
Cc: vinmenon, catalin.marinas, viro, linux-fsdevel, Faiyaz Mohammed
fix the leak of alloc/free traces debugfs interface, reported
by kmemleak like below,
unreferenced object 0xffff00091ae1b540 (size 64):
comm "lsbug", pid 1607, jiffies 4294958291 (age 1476.340s)
hex dump (first 32 bytes):
02 00 00 00 00 00 00 00 6b 6b 6b 6b 6b 6b 6b 6b ........kkkkkkkk
6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
backtrace:
[<ffff8000106b06b8>] slab_post_alloc_hook+0xa0/0x418
[<ffff8000106b5c7c>] kmem_cache_alloc_trace+0x1e4/0x378
[<ffff8000106b5e40>] slab_debugfs_start+0x30/0x50
slab_debugfs_start at mm/slub.c:5831
[<ffff8000107b3dbc>] seq_read_iter+0x214/0xd50
[<ffff8000107b4b84>] seq_read+0x28c/0x418
[<ffff8000109560b4>] full_proxy_read+0xdc/0x148
[<ffff800010738f24>] vfs_read+0x104/0x340
[<ffff800010739ee0>] ksys_read+0xf8/0x1e0
[<ffff80001073a03c>] __arm64_sys_read+0x74/0xa8
[<ffff8000100358d4>] invoke_syscall.constprop.0+0xdc/0x1d8
[<ffff800010035ab4>] do_el0_svc+0xe4/0x298
[<ffff800011138528>] el0_svc+0x20/0x30
[<ffff800011138b08>] el0t_64_sync_handler+0xb0/0xb8
[<ffff80001001259c>] el0t_64_sync+0x178/0x17c
Fixes: 84a2bdb1b458fc968d6d9e07dab388dc679bd747 ("mm: slub: move sysfs slab alloc/free interfaces to debugfs")
Link: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/mm/slub.c?h=next-20210617&id=84a2bdb1b458fc968d6d9e07dab388dc679bd747
Signed-off-by: Faiyaz Mohammed <faiyazm@codeaurora.org>
---
mm/slub.c | 17 +++++------------
1 file changed, 5 insertions(+), 12 deletions(-)
diff --git a/mm/slub.c b/mm/slub.c
index fcb0c50..f006766 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -5785,31 +5785,24 @@ static int slab_debugfs_show(struct seq_file *seq, void *v)
static void slab_debugfs_stop(struct seq_file *seq, void *v)
{
- kfree(v);
}
static void *slab_debugfs_next(struct seq_file *seq, void *v, loff_t *ppos)
{
- loff_t *spos = v;
struct loc_track *t = seq->private;
+ v = ppos;
if (*ppos < t->count) {
- *ppos = ++*spos;
- return spos;
+ ++*ppos;
+ return v;
}
- *ppos = ++*spos;
+ ++*ppos;
return NULL;
}
static void *slab_debugfs_start(struct seq_file *seq, loff_t *ppos)
{
- loff_t *spos = kmalloc(sizeof(loff_t), GFP_KERNEL);
-
- if (!spos)
- return NULL;
-
- *spos = *ppos;
- return spos;
+ return ppos;
}
static const struct seq_operations slab_debugfs_sops = {
--
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a
member of the Code Aurora Forum, hosted by The Linux Foundation
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH v1] mm: slub: fix the leak of alloc/free traces debugfs interface
2021-06-18 12:37 [PATCH v1] mm: slub: fix the leak of alloc/free traces debugfs interface Faiyaz Mohammed
@ 2021-06-18 13:15 ` Andy Shevchenko
2021-06-20 16:01 ` Faiyaz Mohammed
0 siblings, 1 reply; 3+ messages in thread
From: Andy Shevchenko @ 2021-06-18 13:15 UTC (permalink / raw)
To: Faiyaz Mohammed
Cc: Christoph Lameter, Pekka Enberg, David Rientjes, Joonsoo Kim,
Andrew Morton, Vlastimil Babka, linux-mm,
Linux Kernel Mailing List, Greg KH, glittao, vinmenon,
Catalin Marinas, Alexander Viro, Linux FS Devel
On Fri, Jun 18, 2021 at 3:38 PM Faiyaz Mohammed <faiyazm@codeaurora.org> wrote:
>
> fix the leak of alloc/free traces debugfs interface, reported
Fix
> by kmemleak like below,
>
> unreferenced object 0xffff00091ae1b540 (size 64):
> comm "lsbug", pid 1607, jiffies 4294958291 (age 1476.340s)
> hex dump (first 32 bytes):
> 02 00 00 00 00 00 00 00 6b 6b 6b 6b 6b 6b 6b 6b ........kkkkkkkk
> 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
> backtrace:
> [<ffff8000106b06b8>] slab_post_alloc_hook+0xa0/0x418
> [<ffff8000106b5c7c>] kmem_cache_alloc_trace+0x1e4/0x378
> [<ffff8000106b5e40>] slab_debugfs_start+0x30/0x50
> slab_debugfs_start at mm/slub.c:5831
> [<ffff8000107b3dbc>] seq_read_iter+0x214/0xd50
> [<ffff8000107b4b84>] seq_read+0x28c/0x418
> [<ffff8000109560b4>] full_proxy_read+0xdc/0x148
> [<ffff800010738f24>] vfs_read+0x104/0x340
> [<ffff800010739ee0>] ksys_read+0xf8/0x1e0
> [<ffff80001073a03c>] __arm64_sys_read+0x74/0xa8
> [<ffff8000100358d4>] invoke_syscall.constprop.0+0xdc/0x1d8
> [<ffff800010035ab4>] do_el0_svc+0xe4/0x298
> [<ffff800011138528>] el0_svc+0x20/0x30
> [<ffff800011138b08>] el0t_64_sync_handler+0xb0/0xb8
> [<ffff80001001259c>] el0t_64_sync+0x178/0x17c
Can you shrink this a bit?
> Fixes: 84a2bdb1b458fc968d6d9e07dab388dc679bd747 ("mm: slub: move sysfs slab alloc/free interfaces to debugfs")
We use 12, which is shorter.
> Link: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/mm/slub.c?h=next-20210617&id=84a2bdb1b458fc968d6d9e07dab388dc679bd747
>
Must be no blank lines in the tag block.
> Signed-off-by: Faiyaz Mohammed <faiyazm@codeaurora.org>
...
> static void *slab_debugfs_next(struct seq_file *seq, void *v, loff_t *ppos)
> {
> - loff_t *spos = v;
> struct loc_track *t = seq->private;
>
> + v = ppos;
> if (*ppos < t->count) {
> - *ppos = ++*spos;
> - return spos;
> + ++*ppos;
> + return v;
> }
> - *ppos = ++*spos;
> + ++*ppos;
> return NULL;
Can it be
v = ppos;
++*ppos;
if (*ppos <= t->count)
return v;
return NULL;
? (basically the question is, is the comparison equivalent in this case or not)
> }
--
With Best Regards,
Andy Shevchenko
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH v1] mm: slub: fix the leak of alloc/free traces debugfs interface
2021-06-18 13:15 ` Andy Shevchenko
@ 2021-06-20 16:01 ` Faiyaz Mohammed
0 siblings, 0 replies; 3+ messages in thread
From: Faiyaz Mohammed @ 2021-06-20 16:01 UTC (permalink / raw)
To: Andy Shevchenko
Cc: Christoph Lameter, Pekka Enberg, David Rientjes, Joonsoo Kim,
Andrew Morton, Vlastimil Babka, linux-mm,
Linux Kernel Mailing List, Greg KH, glittao, vinmenon,
Catalin Marinas, Alexander Viro, Linux FS Devel
On 6/18/2021 6:45 PM, Andy Shevchenko wrote:
> On Fri, Jun 18, 2021 at 3:38 PM Faiyaz Mohammed <faiyazm@codeaurora.org> wrote:
>>
>> fix the leak of alloc/free traces debugfs interface, reported
>
> Fix
>
Okay, I will update in next patch version.
>> by kmemleak like below,
>>
>> unreferenced object 0xffff00091ae1b540 (size 64):
>> comm "lsbug", pid 1607, jiffies 4294958291 (age 1476.340s)
>> hex dump (first 32 bytes):
>> 02 00 00 00 00 00 00 00 6b 6b 6b 6b 6b 6b 6b 6b ........kkkkkkkk
>> 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
>> backtrace:
>> [<ffff8000106b06b8>] slab_post_alloc_hook+0xa0/0x418
>> [<ffff8000106b5c7c>] kmem_cache_alloc_trace+0x1e4/0x378
>> [<ffff8000106b5e40>] slab_debugfs_start+0x30/0x50
>> slab_debugfs_start at mm/slub.c:5831
>> [<ffff8000107b3dbc>] seq_read_iter+0x214/0xd50
>> [<ffff8000107b4b84>] seq_read+0x28c/0x418
>> [<ffff8000109560b4>] full_proxy_read+0xdc/0x148
>> [<ffff800010738f24>] vfs_read+0x104/0x340
>> [<ffff800010739ee0>] ksys_read+0xf8/0x1e0
>> [<ffff80001073a03c>] __arm64_sys_read+0x74/0xa8
>> [<ffff8000100358d4>] invoke_syscall.constprop.0+0xdc/0x1d8
>> [<ffff800010035ab4>] do_el0_svc+0xe4/0x298
>> [<ffff800011138528>] el0_svc+0x20/0x30
>> [<ffff800011138b08>] el0t_64_sync_handler+0xb0/0xb8
>> [<ffff80001001259c>] el0t_64_sync+0x178/0x17c
>
> Can you shrink this a bit?
>
Okay
>> Fixes: 84a2bdb1b458fc968d6d9e07dab388dc679bd747 ("mm: slub: move sysfs slab alloc/free interfaces to debugfs")
>
> We use 12, which is shorter.
>
>> Link: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/mm/slub.c?h=next-20210617&id=84a2bdb1b458fc968d6d9e07dab388dc679bd747
>
>>
>
> Must be no blank lines in the tag block.
> >> Signed-off-by: Faiyaz Mohammed <faiyazm@codeaurora.org>
>
Okay
> ...
>
>> static void *slab_debugfs_next(struct seq_file *seq, void *v, loff_t *ppos)
>> {
>> - loff_t *spos = v;
>> struct loc_track *t = seq->private;
>>
>> + v = ppos;
>> if (*ppos < t->count) {
>> - *ppos = ++*spos;
>> - return spos;
>> + ++*ppos;
>> + return v;
>> }
>> - *ppos = ++*spos;
>> + ++*ppos;
>> return NULL;
>
> Can it be
>
> v = ppos;
> ++*ppos;
> if (*ppos <= t->count> return v;
> return NULL;
>
> ? (basically the question is, is the comparison equivalent in this case or not)
>
>> }
>Yes, we can update it and slab_debugfs_show has the index check as well.
I will update in next patch version.
Thanks and regards,
Mohammed Faiyaz
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2021-06-20 16:01 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-06-18 12:37 [PATCH v1] mm: slub: fix the leak of alloc/free traces debugfs interface Faiyaz Mohammed
2021-06-18 13:15 ` Andy Shevchenko
2021-06-20 16:01 ` Faiyaz Mohammed
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).