From 72acd64df4561593d2ec3227b4aca9b0d7ded50e Mon Sep 17 00:00:00 2001 From: Colin Ian King Date: Sun, 27 May 2018 23:55:10 +0100 Subject: EVM: Fix null dereference on xattr when xattr fails to allocate In the case where the allocation of xattr fails and xattr is NULL, the error exit return path via label 'out' will dereference xattr when kfree'ing xattr-name. Fix this by only kfree'ing xattr->name and xattr when xattr is non-null. Detected by CoverityScan, CID#1469366 ("Dereference after null check") Fixes: fa516b66a1bf ("EVM: Allow runtime modification of the set of verified xattrs") Signed-off-by: Colin Ian King Signed-off-by: Mimi Zohar --- security/integrity/evm/evm_secfs.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'security') diff --git a/security/integrity/evm/evm_secfs.c b/security/integrity/evm/evm_secfs.c index fb8bc950aceb4..cf5cd303d7c07 100644 --- a/security/integrity/evm/evm_secfs.c +++ b/security/integrity/evm/evm_secfs.c @@ -253,8 +253,10 @@ static ssize_t evm_write_xattrs(struct file *file, const char __user *buf, out: audit_log_format(ab, " res=%d", err); audit_log_end(ab); - kfree(xattr->name); - kfree(xattr); + if (xattr) { + kfree(xattr->name); + kfree(xattr); + } return err; } -- cgit v1.2.3