From: Li Guifu <bluce.liguifu@xxxxxxxxxx> [ 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@xxxxxxxxxx> Reviewed-by: Chao Yu <yuchao0@xxxxxxxxxx> Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- fs/f2fs/super.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c index 9782250c98156..161ce0eb8891a 100644 --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -1004,6 +1004,9 @@ static void f2fs_put_super(struct super_block *sb) int i; bool dropped; + /* unregister procfs/sysfs entries in advance to avoid race case */ + f2fs_unregister_sysfs(sbi); + f2fs_quota_off_umount(sb); /* prevent remaining shrinker jobs */ @@ -1067,8 +1070,6 @@ 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); -- 2.25.1
