From: Alexei Starovoitov Date: Wed, 12 Apr 2023 17:12:52 +0000 (-0700) Subject: bpf: Handle NULL in bpf_local_storage_free. X-Git-Tag: v6.4-rc1~77^2~118^2~16 X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=10fd5f70c397782a97f411f25bfb312ea92b55bc;p=tomoyo%2Ftomoyo-test1.git bpf: Handle NULL in bpf_local_storage_free. During OOM bpf_local_storage_alloc() may fail to allocate 'storage' and call to bpf_local_storage_free() with NULL pointer will cause a crash like: [ 271718.917646] BUG: kernel NULL pointer dereference, address: 00000000000000a0 [ 271719.019620] RIP: 0010:call_rcu+0x2d/0x240 [ 271719.216274] bpf_local_storage_alloc+0x19e/0x1e0 [ 271719.250121] bpf_local_storage_update+0x33b/0x740 Fixes: 7e30a8477b0b ("bpf: Add bpf_local_storage_free()") Signed-off-by: Alexei Starovoitov Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20230412171252.15635-1-alexei.starovoitov@gmail.com --- diff --git a/kernel/bpf/bpf_local_storage.c b/kernel/bpf/bpf_local_storage.c index dab2ff4c99d9..47d9948d768f 100644 --- a/kernel/bpf/bpf_local_storage.c +++ b/kernel/bpf/bpf_local_storage.c @@ -157,6 +157,9 @@ static void bpf_local_storage_free(struct bpf_local_storage *local_storage, struct bpf_local_storage_map *smap, bool bpf_ma, bool reuse_now) { + if (!local_storage) + return; + if (!bpf_ma) { __bpf_local_storage_free(local_storage, reuse_now); return;