This patch adds a test to ensure bpf_setsockopt(TCP_CONGESTION, "not_exist")
will not trigger the kernel module autoload.
Before the fix:
[ 40.535829] BUG: sleeping function called from invalid context at include/linux/sched/mm.h:274
[...]
[ 40.552134] tcp_ca_find_autoload.constprop.0+0xcb/0x200
[ 40.552689] tcp_set_congestion_control+0x99/0x7b0
[ 40.553203] do_tcp_setsockopt+0x3ed/0x2240
[...]
[ 40.556041] __bpf_setsockopt+0x124/0x640
Signed-off-by: Martin KaFai Lau <martin.lau@linux.dev>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20220830231953.792412-1-martin.lau@linux.dev
unsigned int flip:1;
};
+static const char not_exist_cc[] = "not_exist";
static const char cubic_cc[] = "cubic";
static const char reno_cc[] = "reno";
const char *new_cc;
int new_cc_len;
+ if (!bpf_setsockopt(ctx, IPPROTO_TCP, TCP_CONGESTION,
+ (void *)not_exist_cc, sizeof(not_exist_cc)))
+ return 1;
if (bpf_getsockopt(ctx, IPPROTO_TCP, TCP_CONGESTION, old_cc, sizeof(old_cc)))
return 1;
if (!bpf_strncmp(old_cc, sizeof(old_cc), cubic_cc)) {