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authorWang Hai <wanghai38@huawei.com>2020-06-04 01:56:21 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-06-20 11:25:05 +0300
commit5f68457ed16831df9aaa4b9156d06250cf863068 (patch)
tree5c96698620359b75bf07e1aabf0fb9e5a65d0cbd
parent61f8b8965c11df8f0eedce895f8eeb6eb7c1538f (diff)
downloadlinux-5f68457ed16831df9aaa4b9156d06250cf863068.tar.xz
mm/slub: fix a memory leak in sysfs_slab_add()
commit dde3c6b72a16c2db826f54b2d49bdea26c3534a2 upstream. syzkaller reports for memory leak when kobject_init_and_add() returns an error in the function sysfs_slab_add() [1] When this happened, the function kobject_put() is not called for the corresponding kobject, which potentially leads to memory leak. This patch fixes the issue by calling kobject_put() even if kobject_init_and_add() fails. [1] BUG: memory leak unreferenced object 0xffff8880a6d4be88 (size 8): comm "syz-executor.3", pid 946, jiffies 4295772514 (age 18.396s) hex dump (first 8 bytes): 70 69 64 5f 33 00 ff ff pid_3... backtrace: kstrdup+0x35/0x70 mm/util.c:60 kstrdup_const+0x3d/0x50 mm/util.c:82 kvasprintf_const+0x112/0x170 lib/kasprintf.c:48 kobject_set_name_vargs+0x55/0x130 lib/kobject.c:289 kobject_add_varg lib/kobject.c:384 [inline] kobject_init_and_add+0xd8/0x170 lib/kobject.c:473 sysfs_slab_add+0x1d8/0x290 mm/slub.c:5811 __kmem_cache_create+0x50a/0x570 mm/slub.c:4384 create_cache+0x113/0x1e0 mm/slab_common.c:407 kmem_cache_create_usercopy+0x1a1/0x260 mm/slab_common.c:505 kmem_cache_create+0xd/0x10 mm/slab_common.c:564 create_pid_cachep kernel/pid_namespace.c:54 [inline] create_pid_namespace kernel/pid_namespace.c:96 [inline] copy_pid_ns+0x77c/0x8f0 kernel/pid_namespace.c:148 create_new_namespaces+0x26b/0xa30 kernel/nsproxy.c:95 unshare_nsproxy_namespaces+0xa7/0x1e0 kernel/nsproxy.c:229 ksys_unshare+0x3d2/0x770 kernel/fork.c:2969 __do_sys_unshare kernel/fork.c:3037 [inline] __se_sys_unshare kernel/fork.c:3035 [inline] __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3035 do_syscall_64+0xa1/0x530 arch/x86/entry/common.c:295 Fixes: 80da026a8e5d ("mm/slub: fix slab double-free in case of duplicate sysfs filename") Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Wang Hai <wanghai38@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Link: http://lkml.kernel.org/r/20200602115033.1054-1-wanghai38@huawei.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--mm/slub.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/mm/slub.c b/mm/slub.c
index 481518c3f61a..8807a0c98a67 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -5727,8 +5727,10 @@ static int sysfs_slab_add(struct kmem_cache *s)
s->kobj.kset = kset;
err = kobject_init_and_add(&s->kobj, &slab_ktype, NULL, "%s", name);
- if (err)
+ if (err) {
+ kobject_put(&s->kobj);
goto out;
+ }
err = sysfs_create_group(&s->kobj, &slab_attr_group);
if (err)