Messages in this thread Patch in this message | | | From | Kuniyuki Iwashima <> | Subject | [PATCH v1 net 16/16] ipv4: Fix a data-race around sysctl_fib_sync_mem. | Date | Tue, 5 Jul 2022 22:21:30 -0700 |
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While reading sysctl_fib_sync_mem, it can be changed concurrently. So, we need to add READ_ONCE(). Then we can set proc_douintvec_minmax_lockless() as the handler to mark it safe.
Fixes: 9ab948a91b2c ("ipv4: Allow amount of dirty memory from fib resizing to be controllable") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> --- CC: David Ahern <dsahern@gmail.com> --- net/ipv4/fib_trie.c | 2 +- net/ipv4/sysctl_net_ipv4.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c index 2734c3af7e24..46e8a5125853 100644 --- a/net/ipv4/fib_trie.c +++ b/net/ipv4/fib_trie.c @@ -498,7 +498,7 @@ static void tnode_free(struct key_vector *tn) tn = container_of(head, struct tnode, rcu)->kv; } - if (tnode_free_size >= sysctl_fib_sync_mem) { + if (tnode_free_size >= READ_ONCE(sysctl_fib_sync_mem)) { tnode_free_size = 0; synchronize_rcu(); } diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c index 3b1d18be0857..7ea681df37c4 100644 --- a/net/ipv4/sysctl_net_ipv4.c +++ b/net/ipv4/sysctl_net_ipv4.c @@ -578,7 +578,7 @@ static struct ctl_table ipv4_table[] = { .data = &sysctl_fib_sync_mem, .maxlen = sizeof(sysctl_fib_sync_mem), .mode = 0644, - .proc_handler = proc_douintvec_minmax, + .proc_handler = proc_douintvec_minmax_lockless, .extra1 = &sysctl_fib_sync_mem_min, .extra2 = &sysctl_fib_sync_mem_max, }, -- 2.30.2
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