| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.6 95/96] vfs: ioctl: prevent double-fetch in dedupe ioctl | Date | Mon, 8 Aug 2016 21:11:58 +0200 |
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4.6-stable review patch. If anyone has any objections, please let me know.
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From: Scott Bauer <sbauer@plzdonthack.me>
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>
--- fs/ioctl.c | 1 + 1 file changed, 1 insertion(+)
--- a/fs/ioctl.c +++ b/fs/ioctl.c @@ -590,6 +590,7 @@ static long ioctl_file_dedupe_range(stru goto out; } + same->dest_count = count; ret = vfs_dedupe_file_range(file, same); if (ret) goto out;
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