Patch "ipv6: sr: fix memleak in seg6_hmac_init_algo" has been added to the 6.6-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    ipv6: sr: fix memleak in seg6_hmac_init_algo

to the 6.6-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     ipv6-sr-fix-memleak-in-seg6_hmac_init_algo.patch
and it can be found in the queue-6.6 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 79fe45d24eee60c54e7900c61457e6b85ae408af
Author: Hangbin Liu <liuhangbin@xxxxxxxxx>
Date:   Fri May 17 08:54:35 2024 +0800

    ipv6: sr: fix memleak in seg6_hmac_init_algo
    
    [ Upstream commit efb9f4f19f8e37fde43dfecebc80292d179f56c6 ]
    
    seg6_hmac_init_algo returns without cleaning up the previous allocations
    if one fails, so it's going to leak all that memory and the crypto tfms.
    
    Update seg6_hmac_exit to only free the memory when allocated, so we can
    reuse the code directly.
    
    Fixes: bf355b8d2c30 ("ipv6: sr: add core files for SR HMAC support")
    Reported-by: Sabrina Dubroca <sd@xxxxxxxxxxxxxxx>
    Closes: https://lore.kernel.org/netdev/Zj3bh-gE7eT6V6aH@hog/
    Signed-off-by: Hangbin Liu <liuhangbin@xxxxxxxxx>
    Reviewed-by: Simon Horman <horms@xxxxxxxxxx>
    Reviewed-by: Sabrina Dubroca <sd@xxxxxxxxxxxxxxx>
    Link: https://lore.kernel.org/r/20240517005435.2600277-1-liuhangbin@xxxxxxxxx
    Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/net/ipv6/seg6_hmac.c b/net/ipv6/seg6_hmac.c
index d43c50a7310d6..3c3800223e0e0 100644
--- a/net/ipv6/seg6_hmac.c
+++ b/net/ipv6/seg6_hmac.c
@@ -354,6 +354,7 @@ static int seg6_hmac_init_algo(void)
 	struct crypto_shash *tfm;
 	struct shash_desc *shash;
 	int i, alg_count, cpu;
+	int ret = -ENOMEM;
 
 	alg_count = ARRAY_SIZE(hmac_algos);
 
@@ -364,12 +365,14 @@ static int seg6_hmac_init_algo(void)
 		algo = &hmac_algos[i];
 		algo->tfms = alloc_percpu(struct crypto_shash *);
 		if (!algo->tfms)
-			return -ENOMEM;
+			goto error_out;
 
 		for_each_possible_cpu(cpu) {
 			tfm = crypto_alloc_shash(algo->name, 0, 0);
-			if (IS_ERR(tfm))
-				return PTR_ERR(tfm);
+			if (IS_ERR(tfm)) {
+				ret = PTR_ERR(tfm);
+				goto error_out;
+			}
 			p_tfm = per_cpu_ptr(algo->tfms, cpu);
 			*p_tfm = tfm;
 		}
@@ -381,18 +384,22 @@ static int seg6_hmac_init_algo(void)
 
 		algo->shashs = alloc_percpu(struct shash_desc *);
 		if (!algo->shashs)
-			return -ENOMEM;
+			goto error_out;
 
 		for_each_possible_cpu(cpu) {
 			shash = kzalloc_node(shsize, GFP_KERNEL,
 					     cpu_to_node(cpu));
 			if (!shash)
-				return -ENOMEM;
+				goto error_out;
 			*per_cpu_ptr(algo->shashs, cpu) = shash;
 		}
 	}
 
 	return 0;
+
+error_out:
+	seg6_hmac_exit();
+	return ret;
 }
 
 int __init seg6_hmac_init(void)
@@ -410,22 +417,29 @@ int __net_init seg6_hmac_net_init(struct net *net)
 void seg6_hmac_exit(void)
 {
 	struct seg6_hmac_algo *algo = NULL;
+	struct crypto_shash *tfm;
+	struct shash_desc *shash;
 	int i, alg_count, cpu;
 
 	alg_count = ARRAY_SIZE(hmac_algos);
 	for (i = 0; i < alg_count; i++) {
 		algo = &hmac_algos[i];
-		for_each_possible_cpu(cpu) {
-			struct crypto_shash *tfm;
-			struct shash_desc *shash;
 
-			shash = *per_cpu_ptr(algo->shashs, cpu);
-			kfree(shash);
-			tfm = *per_cpu_ptr(algo->tfms, cpu);
-			crypto_free_shash(tfm);
+		if (algo->shashs) {
+			for_each_possible_cpu(cpu) {
+				shash = *per_cpu_ptr(algo->shashs, cpu);
+				kfree(shash);
+			}
+			free_percpu(algo->shashs);
+		}
+
+		if (algo->tfms) {
+			for_each_possible_cpu(cpu) {
+				tfm = *per_cpu_ptr(algo->tfms, cpu);
+				crypto_free_shash(tfm);
+			}
+			free_percpu(algo->tfms);
 		}
-		free_percpu(algo->tfms);
-		free_percpu(algo->shashs);
 	}
 }
 EXPORT_SYMBOL(seg6_hmac_exit);