From: Colin Ian King <[email protected]>

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 <[email protected]>
---
 security/integrity/evm/evm_secfs.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/security/integrity/evm/evm_secfs.c 
b/security/integrity/evm/evm_secfs.c
index fb8bc950aceb..cf5cd303d7c0 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;
 }
 
-- 
2.17.0

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