| From libaokun@huaweicloud.com Tue Jul 16 15:13:28 2024 |
| From: libaokun@huaweicloud.com |
| Date: Tue, 16 Jul 2024 17:29:29 +0800 |
| Subject: ext4: avoid ptr null pointer dereference |
| To: stable@vger.kernel.org, gregkh@linuxfoundation.org |
| Cc: sashal@kernel.org, tytso@mit.edu, jack@suse.cz, patches@lists.linux.dev, yi.zhang@huawei.com, yangerkun@huawei.com, libaokun@huaweicloud.com, Baokun Li <libaokun1@huawei.com> |
| Message-ID: <20240716092929.864207-1-libaokun@huaweicloud.com> |
| |
| From: Baokun Li <libaokun1@huawei.com> |
| |
| When commit 13df4d44a3aa ("ext4: fix slab-out-of-bounds in |
| ext4_mb_find_good_group_avg_frag_lists()") was backported to stable, the |
| commit f536808adcc3 ("ext4: refactor out ext4_generic_attr_store()") that |
| uniformly determines if the ptr is null is not merged in, so it needs to |
| be judged whether ptr is null or not in each case of the switch, otherwise |
| null pointer dereferencing may occur. |
| |
| Fixes: b829687ae122 ("ext4: fix slab-out-of-bounds in ext4_mb_find_good_group_avg_frag_lists()") |
| Signed-off-by: Baokun Li <libaokun1@huawei.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| fs/ext4/sysfs.c | 2 ++ |
| 1 file changed, 2 insertions(+) |
| |
| --- a/fs/ext4/sysfs.c |
| +++ b/fs/ext4/sysfs.c |
| @@ -473,6 +473,8 @@ static ssize_t ext4_attr_store(struct ko |
| *((unsigned int *) ptr) = t; |
| return len; |
| case attr_clusters_in_group: |
| + if (!ptr) |
| + return 0; |
| ret = kstrtouint(skip_spaces(buf), 0, &t); |
| if (ret) |
| return ret; |
