[PATCH][next] ima: ima_modsig: Fix use-after-free bug in ima_read_modsig
flat view
STALE2597d
From: Gustavo A. R. Silva <hidden>
Date: 2019-08-11 23:55:12
Also in:
linux-integrity, lkml
Subsystem:
extended verification module (evm), integrity measurement architecture (ima), security subsystem, the rest · Maintainers:
Mimi Zohar, Roberto Sassu, Dmitry Kasatkin, Paul Moore, James Morris, "Serge E. Hallyn", Linus Torvalds
hdr is being freed and then dereferenced by accessing hdr->pkcs7_msg
Fix this by copying the value returned by PTR_ERR(hdr->pkcs7_msg) into
automatic variable err for its safe use after freeing hdr.
Addresses-Coverity-ID: 1485813 ("Read from pointer after free")
Fixes: 39b07096364a ("ima: Implement support for module-style appended signatures")
Signed-off-by: Gustavo A. R. Silva <redacted>
---
security/integrity/ima/ima_modsig.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/security/integrity/ima/ima_modsig.c b/security/integrity/ima/ima_modsig.c
index c412e31d1714..e681d4326145 100644
--- a/security/integrity/ima/ima_modsig.c
+++ b/security/integrity/ima/ima_modsig.c@@ -91,8 +91,9 @@ int ima_read_modsig(enum ima_hooks func, const void *buf, loff_t buf_len, hdr->pkcs7_msg = pkcs7_parse_message(buf + buf_len, sig_len); if (IS_ERR(hdr->pkcs7_msg)) { + int err = PTR_ERR(hdr->pkcs7_msg); kfree(hdr); - return PTR_ERR(hdr->pkcs7_msg); + return err; } memcpy(hdr->raw_pkcs7, buf + buf_len, sig_len);
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2.22.0