Commits
Jakub Kicinski committed 9188d5ca454
net/tls: fix refcount adjustment in fallback
Unlike atomic_add(), refcount_add() does not deal well
with a negative argument. TLS fallback code reallocates
the skb and is very likely to shrink the truesize, leading to:
[ 189.513254] WARNING: CPU: 5 PID: 0 at lib/refcount.c:81 refcount_add_not_zero_checked+0x15c/0x180
Call Trace:
refcount_add_checked+0x6/0x40
tls_enc_skb+0xb93/0x13e0 [tls]
Once wmem_allocated count saturates the application can no longer
send data on the socket. This is similar to Eric's fixes for GSO,
TCP:
commit 7ec318feeed1 ("tcp: gso: avoid refcount_t warning from tcp_gso_segment()")
and UDP:
commit 575b65bc5bff ("udp: avoid refcount_t saturation in __udp_gso_segment()").
Unlike the GSO case, for TLS fallback it's likely that the skb has
shrunk, so the "likely" annotation is the other way around (likely
branch being "sub").
Fixes: e8f69799810c ("net/tls: Add generic NIC offload infrastructure")
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: John Hurley <john.hurley@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>