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| author | Scott Bauer <sbauer@plzdonthack.me> | 2016-07-27 19:11:29 -0600 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-07-28 15:23:12 -0700 |
| commit | 10eec60ce79187686e052092e5383c99b4420a20 (patch) | |
| tree | 27093bca5e5208aa8e8e04e28b3cc5df4ecbf0af /fs/ioctl.c | |
| parent | 884316deb4c9fdf9becfa31831a9e40717e3026c (diff) | |
| download | linux-0-day-10eec60ce79187686e052092e5383c99b4420a20.tar.gz linux-0-day-10eec60ce79187686e052092e5383c99b4420a20.tar.xz | |
vfs: ioctl: prevent double-fetch in dedupe ioctl
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>
Diffstat (limited to 'fs/ioctl.c')
| -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 116a333e9c773..0f56deb24ce65 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; |