diff mbox series

[v2,7/8] net: inet: do not leave a dangling sk pointer in inet_create()

Message ID 20241007213502.28183-8-ignat@cloudflare.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series do not leave dangling sk pointers in pf->create functions | expand

Checks

Context Check Description
netdev/series_format warning Target tree name not specified in the subject
netdev/tree_selection success Guessed tree name to be net-next
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 6 this patch: 6
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers success CCed 5 of 5 maintainers
netdev/build_clang success Errors and warnings before: 6 this patch: 6
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 5 this patch: 5
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 42 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Ignat Korchagin Oct. 7, 2024, 9:35 p.m. UTC 
sock_init_data() attaches the allocated sk object to the provided sock
object. If inet_create() fails later, the sk object is freed, but the
sock object retains the dangling pointer, which may create use-after-free
later.

Clear the sk pointer in the sock object on error.

Signed-off-by: Ignat Korchagin <ignat@cloudflare.com>
---
 net/ipv4/af_inet.c | 22 ++++++++++------------
 1 file changed, 10 insertions(+), 12 deletions(-)
diff mbox series

Patch

diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index b24d74616637..8095e82de808 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -376,32 +376,30 @@  static int inet_create(struct net *net, struct socket *sock, int protocol,
 		inet->inet_sport = htons(inet->inet_num);
 		/* Add to protocol hash chains. */
 		err = sk->sk_prot->hash(sk);
-		if (err) {
-			sk_common_release(sk);
-			goto out;
-		}
+		if (err)
+			goto out_sk_release;
 	}
 
 	if (sk->sk_prot->init) {
 		err = sk->sk_prot->init(sk);
-		if (err) {
-			sk_common_release(sk);
-			goto out;
-		}
+		if (err)
+			goto out_sk_release;
 	}
 
 	if (!kern) {
 		err = BPF_CGROUP_RUN_PROG_INET_SOCK(sk);
-		if (err) {
-			sk_common_release(sk);
-			goto out;
-		}
+		if (err)
+			goto out_sk_release;
 	}
 out:
 	return err;
 out_rcu_unlock:
 	rcu_read_unlock();
 	goto out;
+out_sk_release:
+	sk_common_release(sk);
+	sock->sk = NULL;
+	goto out;
 }