Commit 6352a293 authored Jul 28, 2009 by Tyler Hicks Committed by Linus Torvalds Jul 28, 2009

eCryptfs: Check Tag 11 literal data buffer size

Tag 11 packets are stored in the metadata section of an eCryptfs file to
store the key signature(s) used to encrypt the file encryption key.
After extracting the packet length field to determine the key signature
length, a check is not performed to see if the length would exceed the
key signature buffer size that was passed into parse_tag_11_packet().

Thanks to Ramon de Carvalho Valle for finding this bug using fsfuzzer.

Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Cc: stable@kernel.org (2.6.27 and 30)
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 4733fd32

fs/ecryptfs/keystore.c

+6 −0

Original line number	Diff line number	Diff line
		@@ -1449,6 +1449,12 @@ parse_tag_11_packet(unsigned char data, unsigned char contents,
		rc = -EINVAL;
		goto out;
		}
		if (unlikely((*tag_11_contents_size) > max_contents_bytes)) {
		printk(KERN_ERR "Literal data section in tag 11 packet exceeds "
		"expected size\n");
		rc = -EINVAL;
		goto out;
		}
		if (data[(*packet_size)++] != 0x62) {
		printk(KERN_WARNING "Unrecognizable packet\n");
		rc = -EINVAL;

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