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* [PATCH] net: ipv4: Potential null pointer dereference in cipso_v4_parsetag_enum
@ 2025-09-08  8:03 Chen Yufeng
  2025-09-08 10:09 ` Vadim Fedorenko
                   ` (3 more replies)
  0 siblings, 4 replies; 5+ messages in thread
From: Chen Yufeng @ 2025-09-08  8:03 UTC (permalink / raw)
  To: paul; +Cc: davem, dsahern, netdev, Chen Yufeng

While parsing CIPSO enumerated tags, secattr->flags is set to 
NETLBL_SECATTR_MLS_CAT even if secattr->attr.mls.cat is NULL.
If subsequent code attempts to access secattr->attr.mls.cat, 
it may lead to a null pointer dereference, causing a system crash.

To address this issue, we add a check to ensure that before setting
the NETLBL_SECATTR_MLS_CAT flag, secattr->attr.mls.cat is not NULL.

fixed code:
```
if (secattr->attr.mls.cat)
    secattr->flags |= NETLBL_SECATTR_MLS_CAT;
```

This patch is similar to eead1c2ea250("netlabel: cope with NULL catmap").

Signed-off-by: Chen Yufeng <chenyufeng@iie.ac.cn>
---
 net/ipv4/cipso_ipv4.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c
index 740af8541d2f..2190333d78cb 100644
--- a/net/ipv4/cipso_ipv4.c
+++ b/net/ipv4/cipso_ipv4.c
@@ -1339,8 +1339,8 @@ static int cipso_v4_parsetag_enum(const struct cipso_v4_doi *doi_def,
 			netlbl_catmap_free(secattr->attr.mls.cat);
 			return ret_val;
 		}
-
-		secattr->flags |= NETLBL_SECATTR_MLS_CAT;
+		if (secattr->attr.mls.cat)
+			secattr->flags |= NETLBL_SECATTR_MLS_CAT;
 	}
 
 	return 0;
-- 
2.34.1


^ permalink raw reply related	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2025-09-10  0:09 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2025-09-08  8:03 [PATCH] net: ipv4: Potential null pointer dereference in cipso_v4_parsetag_enum Chen Yufeng
2025-09-08 10:09 ` Vadim Fedorenko
2025-09-08 14:56 ` Paul Moore
2025-09-09 12:47 ` Simon Horman
2025-09-10  0:09 ` Jakub Kicinski

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