From: Chao Yu <chao@kernel.org>
To: Christophe JAILLET <christophe.jaillet@wanadoo.fr>,
"Vlastimil Babka (SUSE)" <vbabka@kernel.org>,
linux-mm@kvack.org
Cc: akpm@linux-foundation.org, linux-kernel@vger.kernel.org,
Chao Yu <chao.yu@oppo.com>,
muchun.song@linux.dev
Subject: Re: [PATCH] mm/slub: fix to return errno if kmalloc() fails
Date: Tue, 13 Sep 2022 11:42:04 +0800 [thread overview]
Message-ID: <e14a916c-a597-5328-2d79-39274fbdad35@kernel.org> (raw)
In-Reply-To: <2025305d-16db-abdf-6cd3-1fb93371c2b4@wanadoo.fr>
On 2022/9/10 0:47, Christophe JAILLET wrote:
> Le 30/08/2022 à 16:10, Chao Yu a écrit :
>> From: Chao Yu <chao.yu@oppo.com>
>>
>> In create_unique_id(), kmalloc(, GFP_KERNEL) can fail due to
>> out-of-memory, if it fails, return errno correctly rather than
>> triggering panic via BUG_ON();
>>
>> kernel BUG at mm/slub.c:5893!
>> Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
>>
>> Call trace:
>> sysfs_slab_add+0x258/0x260 mm/slub.c:5973
>> __kmem_cache_create+0x60/0x118 mm/slub.c:4899
>> create_cache mm/slab_common.c:229 [inline]
>> kmem_cache_create_usercopy+0x19c/0x31c mm/slab_common.c:335
>> kmem_cache_create+0x1c/0x28 mm/slab_common.c:390
>> f2fs_kmem_cache_create fs/f2fs/f2fs.h:2766 [inline]
>> f2fs_init_xattr_caches+0x78/0xb4 fs/f2fs/xattr.c:808
>> f2fs_fill_super+0x1050/0x1e0c fs/f2fs/super.c:4149
>> mount_bdev+0x1b8/0x210 fs/super.c:1400
>> f2fs_mount+0x44/0x58 fs/f2fs/super.c:4512
>> legacy_get_tree+0x30/0x74 fs/fs_context.c:610
>> vfs_get_tree+0x40/0x140 fs/super.c:1530
>> do_new_mount+0x1dc/0x4e4 fs/namespace.c:3040
>> path_mount+0x358/0x914 fs/namespace.c:3370
>> do_mount fs/namespace.c:3383 [inline]
>> __do_sys_mount fs/namespace.c:3591 [inline]
>> __se_sys_mount fs/namespace.c:3568 [inline]
>> __arm64_sys_mount+0x2f8/0x408 fs/namespace.c:3568
>>
>> Cc: <stable@kernel.org>
>> Reported-by: syzbot+81684812ea68216e08c5@syzkaller.appspotmail.com
>> Signed-off-by: Chao Yu <chao.yu@oppo.com>
>> ---
>> mm/slub.c | 5 ++++-
>> 1 file changed, 4 insertions(+), 1 deletion(-)
>>
>> diff --git a/mm/slub.c b/mm/slub.c
>> index 862dbd9af4f5..e6f3727b9ad2 100644
>> --- a/mm/slub.c
>> +++ b/mm/slub.c
>> @@ -5890,7 +5890,8 @@ static char *create_unique_id(struct kmem_cache *s)
>> char *name = kmalloc(ID_STR_LENGTH, GFP_KERNEL);
>
> Hi,
>
> looks that ID_STR_LENGTH could even be reduced to 32 or 16.
>
> The 2nd BUG_ON at the end of the function could certainly be just removed as well or remplaced by a:
> if (p > name + ID_STR_LENGTH - 1) {
> kfree(name);
> return -E<something>;
> }
Hi Christophe, Vlastimil,
Should I include this in v3? or may be in another patch?
Thanks,
>
> Just my 2c,
>
> CJ
>
>> char *p = name;
>> - BUG_ON(!name);
>> + if (!name)
>> + return ERR_PTR(-ENOMEM);
>> *p++ = ':';
>> /*
>> @@ -5948,6 +5949,8 @@ static int sysfs_slab_add(struct kmem_cache *s)
>> * for the symlinks.
>> */
>> name = create_unique_id(s);
>> + if (IS_ERR(name))
>> + return PTR_ERR(name);
>> }
>> s->kobj.kset = kset;
>
next prev parent reply other threads:[~2022-09-13 3:42 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-30 14:10 [PATCH] mm/slub: fix to return errno if kmalloc() fails Chao Yu
2022-08-31 3:09 ` Muchun Song
2022-09-08 21:25 ` Vlastimil Babka (SUSE)
2022-09-09 20:06 ` Matthew Wilcox
2022-09-09 20:21 ` Vlastimil Babka (SUSE)
2022-09-13 3:27 ` Chao Yu
2022-08-31 13:33 ` Hyeonggon Yoo
2022-09-06 21:33 ` David Rientjes
2022-09-09 16:47 ` Christophe JAILLET
2022-09-13 3:42 ` Chao Yu [this message]
2022-09-13 5:26 ` Marion & Christophe JAILLET
2022-09-16 22:58 ` Vlastimil Babka (SUSE)
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