From 8e6139f0bb6304229f935a9a9be5a99922678a95 Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Tue, 24 May 2016 22:47:00 +0200 Subject: [PATCH] hpfs: fix remount failure when there are no options changed Commit 8fe17b071b37 ("hpfs: kstrdup() out of memory handling") checks if the kstrdup function returns NULL due to out-of-memory condition. However, if we are remounting a filesystem with no change to filesystem-specific options, the parameter data is NULL. In this case, kstrdup returns NULL (because it was passed NULL parameter), although no out of memory condition exists. The mount syscall then fails with ENOMEM. This patch fixes the bug. We fail with ENOMEM only if data is non-NULL. The patch also changes the call to replace_mount_options - if we didn't pass any filesystem-specific options, we don't call replace_mount_options (thus we don't erase existing reported options). Fixes: 8fe17b071b37 ("hpfs: kstrdup() out of memory handling") Signed-off-by: Mikulas Patocka Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds --- fs/hpfs/super.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/fs/hpfs/super.c b/fs/hpfs/super.c index 458cf463047b6..46ad0ef8b4cc7 100644 --- a/fs/hpfs/super.c +++ b/fs/hpfs/super.c @@ -455,7 +455,7 @@ static int hpfs_remount_fs(struct super_block *s, int *flags, char *data) struct hpfs_sb_info *sbi = hpfs_sb(s); char *new_opts = kstrdup(data, GFP_KERNEL); - if (!new_opts) + if (data && !new_opts) return -ENOMEM; sync_filesystem(s); @@ -493,7 +493,8 @@ static int hpfs_remount_fs(struct super_block *s, int *flags, char *data) if (!(*flags & MS_RDONLY)) mark_dirty(s, 1); - replace_mount_options(s, new_opts); + if (new_opts) + replace_mount_options(s, new_opts); hpfs_unlock(s); return 0; -- 2.39.5