diff options
| author | Scott Bauer <sbauer@plzdonthack.me> | 2016-07-27 19:11:29 -0600 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-08-10 12:54:50 +0200 |
| commit | 04678f5598322beecf6f06ddf73b2eb6a8b0ef9a (patch) | |
| tree | 820fc7e27b1bd392aab25da2c3db459ae5db5bfe | |
| parent | 900ac92c5514dd8c63a8f3c91942dcb4cc6bd0f3 (diff) | |
vfs: ioctl: prevent double-fetch in dedupe ioctl
commit 10eec60ce79187686e052092e5383c99b4420a20 upstream.
This prevents a double-fetch from user space that can lead to to an
undersized allocation and heap overflow.
Fixes: 54dbc1517237 ("vfs: hoist the btrfs deduplication ioctl to the vfs")
Signed-off-by: Scott Bauer <sbauer@plzdonthack.me>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/ioctl.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/fs/ioctl.c b/fs/ioctl.c index 116a333e9c77..0f56deb24ce6 100644 --- a/fs/ioctl.c +++ b/fs/ioctl.c @@ -590,6 +590,7 @@ static long ioctl_file_dedupe_range(struct file *file, void __user *arg) goto out; } + same->dest_count = count; ret = vfs_dedupe_file_range(file, same); if (ret) goto out; |