netlink: Fix off-by-one error in netlink_proto_init()

Commit Message

Markus Elfring Nov. 3, 2024, 1:15 p.m. UTC

From: Markus Elfring <[e-mail]>
Date: Sun, 3 Nov 2024 14:01:26 +0100

Hash tables should be properly destroyed after a rhashtable_init() call
failed in this function implementation.
The corresponding exception handling was incomplete because of
a questionable condition check.
Thus use the comparison operator “>=” instead for the affected while loop.

This issue was transformed by using the Coccinelle software.

Fixes: e341694e3eb5 ("netlink: Convert netlink_lookup() to use RCU protected hash table")
Cc: [e-mail]
Signed-off-by: Markus Elfring <[e-mail]>
---
 net/netlink/af_netlink.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--
2.47.0

Comments

Kuniyuki Iwashima Nov. 3, 2024, 5:31 p.m. UTC | #1

From: Markus Elfring <[e-mail]>
Date: Sun, 3 Nov 2024 14:15:18 +0100
> From: Markus Elfring <[e-mail]>
> Date: Sun, 3 Nov 2024 14:01:26 +0100
> 
> Hash tables should be properly destroyed after a rhashtable_init() call
> failed in this function implementation.
> The corresponding exception handling was incomplete because of
> a questionable condition check.
> Thus use the comparison operator “>=” instead for the affected while loop.

This patch is already applied to net-next.
https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git/commit/?id=bc74d329ceba

Markus Elfring Nov. 4, 2024, 7:38 a.m. UTC | #2

…
>> Thus use the comparison operator “>=” instead for the affected while loop.
>
> This patch is already applied to net-next.
> https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git/commit/?id=bc74d329ceba

Thanks for your reminder on the commit bc74d329ceba23f998ead4f716266da5afe319f7
("netlink: Remove the dead code in netlink_proto_init()") from 2024-10-31
for another contribution by Jinjie Ruan (also according to your suggestion).

See also:
https://lore.kernel.org/linux-kernel/[e-mail]/
https://lore.kernel.org/linux-kernel/[e-mail]/

Regards,
Markus

Patch

diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 0a9287fadb47..9601b85dda95 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -2936,7 +2936,7 @@  static int __init netlink_proto_init(void)
 	for (i = 0; i < MAX_LINKS; i++) {
 		if (rhashtable_init(&nl_table[i].hash,
 				    &netlink_rhashtable_params) < 0) {
-			while (--i > 0)
+			while (--i >= 0)
 				rhashtable_destroy(&nl_table[i].hash);
 			kfree(nl_table);
 			goto panic;