From 5cb3ec3d605ba80d0f33968d54bf85875d427161 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 44d51706b4685f965cd32acde3fe0fcc1e6198e8 upstream. 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 Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- 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 a561591..76c4697 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; -- 2.7.4