From: Mikulas Patocka Date: Tue, 24 May 2016 20:47:00 +0000 (+0200) Subject: hpfs: fix remount failure when there are no options changed X-Git-Tag: Ubuntu-5.10.0-12.13~12493 X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;h=44d51706b4685f965cd32acde3fe0fcc1e6198e8;p=mirror_ubuntu-hirsute-kernel.git hpfs: fix remount failure when there are no options changed 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 --- diff --git a/fs/hpfs/super.c b/fs/hpfs/super.c index 458cf463047b..46ad0ef8b4cc 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;