From ffd9e8e871d65a6fb87433fe0811289e5dadcd5d Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Tue, 24 May 2016 22:47:00 +0200 Subject: hpfs: fix remount failure when there are no options changed [ Upstream commit 44d51706b4685f965cd32acde3fe0fcc1e6198e8 ] Commit ce657611baf9 ("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: ce657611baf9 ("hpfs: kstrdup() out of memory handling") Signed-off-by: Mikulas Patocka Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- 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 8685c655737f..03b2c9ca2d71 100644 --- a/fs/hpfs/super.c +++ b/fs/hpfs/super.c @@ -428,7 +428,7 @@ 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); @@ -466,7 +466,8 @@ 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; -- cgit v1.2.3