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authorLi Guifu <bluce.liguifu@huawei.com>2020-07-24 04:38:11 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-09-03 12:22:26 +0300
commitde43394549bfbd0ed90b6295e5fbef27042ab718 (patch)
tree84c584924afc8475a822d4cd92649b004cbd61f8
parente6a62b5c4f7a05afec7ea4cfb040fb8512376259 (diff)
downloadlinux-de43394549bfbd0ed90b6295e5fbef27042ab718.tar.xz
f2fs: fix use-after-free issue
[ Upstream commit 99c787cfd2bd04926f1f553b30bd7dcea2caaba1 ] During umount, f2fs_put_super() unregisters procfs entries after f2fs_destroy_segment_manager(), it may cause use-after-free issue when umount races with procfs accessing, fix it by relocating f2fs_unregister_sysfs(). [Chao Yu: change commit title/message a bit] Signed-off-by: Li Guifu <bluce.liguifu@huawei.com> Reviewed-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
-rw-r--r--fs/f2fs/super.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 89319c352406..990339c538b0 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -782,6 +782,9 @@ static void f2fs_put_super(struct super_block *sb)
struct f2fs_sb_info *sbi = F2FS_SB(sb);
int i;
+ /* unregister procfs/sysfs entries in advance to avoid race case */
+ f2fs_unregister_sysfs(sbi);
+
f2fs_quota_off_umount(sb);
/* prevent remaining shrinker jobs */
@@ -834,8 +837,6 @@ static void f2fs_put_super(struct super_block *sb)
kfree(sbi->ckpt);
- f2fs_unregister_sysfs(sbi);
-
sb->s_fs_info = NULL;
if (sbi->s_chksum_driver)
crypto_free_shash(sbi->s_chksum_driver);