From 0040e606e35a0db80fc3fac04ccc7c7176a8e2b1 Mon Sep 17 00:00:00 2001 From: Christoph Jaeger Date: Sat, 12 Apr 2014 13:33:13 +0200 Subject: [PATCH] btrfs: fix use-after-free in mount_subvol() Pointer 'newargs' is used after the memory that it points to has already been freed. Picked up by Coverity - CID 1201425. Fixes: 0723a0473f ("btrfs: allow mounting btrfs subvolumes with different ro/rw options") Signed-off-by: Christoph Jaeger Signed-off-by: Chris Mason --- fs/btrfs/super.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index 994c40955315..53bc3733d483 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -1186,7 +1186,6 @@ static struct dentry *mount_subvol(const char *subvol_name, int flags, return ERR_PTR(-ENOMEM); mnt = vfs_kern_mount(&btrfs_fs_type, flags, device_name, newargs); - kfree(newargs); if (PTR_RET(mnt) == -EBUSY) { if (flags & MS_RDONLY) { @@ -1196,17 +1195,22 @@ static struct dentry *mount_subvol(const char *subvol_name, int flags, int r; mnt = vfs_kern_mount(&btrfs_fs_type, flags | MS_RDONLY, device_name, newargs); - if (IS_ERR(mnt)) + if (IS_ERR(mnt)) { + kfree(newargs); return ERR_CAST(mnt); + } r = btrfs_remount(mnt->mnt_sb, &flags, NULL); if (r < 0) { /* FIXME: release vfsmount mnt ??*/ + kfree(newargs); return ERR_PTR(r); } } } + kfree(newargs); + if (IS_ERR(mnt)) return ERR_CAST(mnt); -- GitLab