This is a note to let you know that I've just added the patch titled evm: Check size of security.evm before using it to the 5.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: evm-check-size-of-security.evm-before-using-it.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 455b6c9112eff8d249e32ba165742085678a80a4 Mon Sep 17 00:00:00 2001 From: Roberto Sassu <roberto.sassu@xxxxxxxxxx> Date: Fri, 4 Sep 2020 11:23:30 +0200 Subject: evm: Check size of security.evm before using it From: Roberto Sassu <roberto.sassu@xxxxxxxxxx> commit 455b6c9112eff8d249e32ba165742085678a80a4 upstream. This patch checks the size for the EVM_IMA_XATTR_DIGSIG and EVM_XATTR_PORTABLE_DIGSIG types to ensure that the algorithm is read from the buffer returned by vfs_getxattr_alloc(). Cc: stable@xxxxxxxxxxxxxxx # 4.19.x Fixes: 5feeb61183dde ("evm: Allow non-SHA1 digital signatures") Signed-off-by: Roberto Sassu <roberto.sassu@xxxxxxxxxx> Signed-off-by: Mimi Zohar <zohar@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- security/integrity/evm/evm_main.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/security/integrity/evm/evm_main.c +++ b/security/integrity/evm/evm_main.c @@ -183,6 +183,12 @@ static enum integrity_status evm_verify_ break; case EVM_IMA_XATTR_DIGSIG: case EVM_XATTR_PORTABLE_DIGSIG: + /* accept xattr with non-empty signature field */ + if (xattr_len <= sizeof(struct signature_v2_hdr)) { + evm_status = INTEGRITY_FAIL; + goto out; + } + hdr = (struct signature_v2_hdr *)xattr_data; digest.hdr.algo = hdr->hash_algo; rc = evm_calc_hash(dentry, xattr_name, xattr_value, Patches currently in stable-queue which might be from roberto.sassu@xxxxxxxxxx are queue-5.4/evm-check-size-of-security.evm-before-using-it.patch