Re: [PATCH 2/4] evm: reset status in evm_inode_post_setattr()
From: Mimi Zohar <zohar@linux.ibm.com>
Date: 2019-05-20 21:20:14
Also in:
linux-doc, linux-integrity, lkml, stable
On Thu, 2019-05-16 at 18:12 +0200, Roberto Sassu wrote:
This patch adds a call to evm_reset_status() in evm_inode_post_setattr(),
before security.evm is updated. The same is done in the other
evm_inode_post_* functions.
Fixes: 523b74b16bcbb ("evm: reset EVM status when file attributes change")
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Cc: stable@vger.kernel.orgWhy all of a sudden do we also need to clear the EVM cached status when modifying the file attributes? The HMAC is being recalculated. If the reason is because of EVM portable and immutable signatures, then the "Fixes" tag is incorrect. Mimi
quoted hunk ↗ jump to hunk
--- security/integrity/evm/evm_main.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c index b6d9f14bc234..b41c2d8a8834 100644 --- a/security/integrity/evm/evm_main.c +++ b/security/integrity/evm/evm_main.c@@ -512,8 +512,11 @@ void evm_inode_post_setattr(struct dentry *dentry, int ia_valid) if (!evm_key_loaded()) return; - if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID)) + if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID)) { + evm_reset_status(dentry->d_inode); + evm_update_evmxattr(dentry, NULL, NULL, 0); + } } /*