From 6352a29305373ae6196491e6d4669f301e26492e Mon Sep 17 00:00:00 2001 From: Tyler Hicks Date: Tue, 28 Jul 2009 13:57:01 -0500 Subject: [PATCH] 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 Cc: stable@kernel.org (2.6.27 and 30) Signed-off-by: Linus Torvalds --- fs/ecryptfs/keystore.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/fs/ecryptfs/keystore.c b/fs/ecryptfs/keystore.c index af737bb56cb7..5414253d4c97 100644 --- a/fs/ecryptfs/keystore.c +++ b/fs/ecryptfs/keystore.c @@ -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; -- 2.20.1