We pass in a pointer in our send arg struct, this means the struct size doesn't
match with 32bit user space and 64bit kernel space. Fix this by adding a compat
mode and doing the appropriate conversion.
Signed-off-by: Josef Bacik <jba...@fb.com>
---
fs/btrfs/ioctl.c | 53 ++++++++++++++++++++++++++++++++++++++++++++++++++++-
fs/btrfs/send.c | 12 ++----------
fs/btrfs/send.h | 2 +-
3 files changed, 55 insertions(+), 12 deletions(-)
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 398495f79c83..6a07d4e12fd2 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -5464,6 +5464,53 @@ static int btrfs_ioctl_set_features(struct file *file,
void __user *arg)
return ret;
}
+#if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
+struct btrfs_ioctl_send_args_32 {
+ __s64 send_fd; /* in */
+ __u64 clone_sources_count; /* in */
+ compat_uptr_t clone_sources; /* in */
+ __u64 parent_root; /* in */
+ __u64 flags; /* in */
+ __u64 reserved[4]; /* in */
+} __attribute__ ((__packed__));
+#define BTRFS_IOC_SEND_32 _IOW(BTRFS_IOCTL_MAGIC, 38, \
+ struct btrfs_ioctl_send_args_32)
+#endif
+
+static int _btrfs_ioctl_send(struct file *file, void __user *argp, bool compat)
+{
+ struct btrfs_ioctl_send_args *arg;
+ int ret;
+
+ if (compat) {
+#if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
+ struct btrfs_ioctl_send_args_32 args32;
+ ret = copy_from_user(&args32, argp, sizeof(args32));
+ if (ret)
+ return -EFAULT;
+ arg = kzalloc(sizeof(*arg), GFP_KERNEL);
+ if (!arg)
+ return -ENOMEM;
+ arg->send_fd = args32.send_fd;
+ arg->clone_sources_count = args32.clone_sources_count;
+ arg->clone_sources = compat_ptr(args32.clone_sources);
+ arg->parent_root = args32.parent_root;
+ arg->flags = args32.flags;
+ memcpy(arg->reserved, args32.reserved,
+ sizeof(args32.reserved));
+#else
+ return -ENOTTY;
+#endif
+ } else {
+ arg = memdup_user(argp, sizeof(*arg));
+ if (IS_ERR(arg))
+ return PTR_ERR(arg);
+ }
+ ret = btrfs_ioctl_send(file, arg);
+ kfree(arg);
+ return ret;
+}
+
long btrfs_ioctl(struct file *file, unsigned int
cmd, unsigned long arg)
{
@@ -5569,7 +5616,11 @@ long btrfs_ioctl(struct file *file, unsigned int
return btrfs_ioctl_set_received_subvol_32(file, argp);
#endif
case BTRFS_IOC_SEND:
- return btrfs_ioctl_send(file, argp);
+ return _btrfs_ioctl_send(file, argp, false);
+#if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
+ case BTRFS_IOC_SEND_32:
+ return _btrfs_ioctl_send(file, argp, true);
+#endif
case BTRFS_IOC_GET_DEV_STATS:
return btrfs_ioctl_get_dev_stats(fs_info, argp);
case BTRFS_IOC_QUOTA_CTL:
diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c
index 0746eda7231d..d9ddcdbdd2e7 100644
--- a/fs/btrfs/send.c
+++ b/fs/btrfs/send.c
@@ -26,6 +26,7 @@
#include <linux/radix-tree.h>
#include <linux/vmalloc.h>
#include <linux/string.h>
+#include <linux/compat.h>
#include "send.h"
#include "backref.h"
@@ -6371,13 +6372,12 @@ static void btrfs_root_dec_send_in_progress(struct
btrfs_root* root)
spin_unlock(&root->root_item_lock);
}
-long btrfs_ioctl_send(struct file *mnt_file, void __user *arg_)
+long btrfs_ioctl_send(struct file *mnt_file, struct btrfs_ioctl_send_args *arg)
{
int ret = 0;
struct btrfs_root *send_root = BTRFS_I(file_inode(mnt_file))->root;
struct btrfs_fs_info *fs_info = send_root->fs_info;
struct btrfs_root *clone_root;
- struct btrfs_ioctl_send_args *arg = NULL;
struct btrfs_key key;
struct send_ctx *sctx = NULL;
u32 i;
@@ -6413,13 +6413,6 @@ long btrfs_ioctl_send(struct file *mnt_file, void __user
*arg_)
goto out;
}
- arg = memdup_user(arg_, sizeof(*arg));
- if (IS_ERR(arg)) {
- ret = PTR_ERR(arg);
- arg = NULL;
- goto out;
- }
-
/*
* Check that we don't overflow at later allocations, we request
* clone_sources_count + 1 items, and compare to unsigned long inside
@@ -6660,7 +6653,6 @@ long btrfs_ioctl_send(struct file *mnt_file, void __user
*arg_)
if (sctx && !IS_ERR_OR_NULL(sctx->parent_root))
btrfs_root_dec_send_in_progress(sctx->parent_root);
- kfree(arg);
kvfree(clone_sources_tmp);
if (sctx) {
diff --git a/fs/btrfs/send.h b/fs/btrfs/send.h
index 02e00166c4da..3aa4bc55754f 100644
--- a/fs/btrfs/send.h
+++ b/fs/btrfs/send.h
@@ -130,5 +130,5 @@ enum {
#define BTRFS_SEND_A_MAX (__BTRFS_SEND_A_MAX - 1)
#ifdef __KERNEL__
-long btrfs_ioctl_send(struct file *mnt_file, void __user *arg);
+long btrfs_ioctl_send(struct file *mnt_file, struct btrfs_ioctl_send_args
*arg);
#endif
--
2.7.4
--
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