From ee5675ecdf7a4e713ed21d98a70c2871d6ebed01 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 16 Mar 2023 01:10:07 +0000 Subject: net/packet: convert po->origdev to an atomic flag syzbot/KCAN reported that po->origdev can be read while another thread is changing its value. We can avoid this splat by converting this field to an actual bit. Following patches will convert remaining 1bit fields. Fixes: 80feaacb8a64 ("[AF_PACKET]: Add option to return orig_dev to userspace.") Signed-off-by: Eric Dumazet Reported-by: syzbot Signed-off-by: David S. Miller --- net/packet/internal.h | 22 +++++++++++++++++++++- 1 file changed, 21 insertions(+), 1 deletion(-) (limited to 'net/packet/internal.h') diff --git a/net/packet/internal.h b/net/packet/internal.h index 48af35b1aed2..178cd1852238 100644 --- a/net/packet/internal.h +++ b/net/packet/internal.h @@ -116,9 +116,9 @@ struct packet_sock { int copy_thresh; spinlock_t bind_lock; struct mutex pg_vec_lock; + unsigned long flags; unsigned int running; /* bind_lock must be held */ unsigned int auxdata:1, /* writer must hold sock lock */ - origdev:1, has_vnet_hdr:1, tp_loss:1, tp_tx_has_off:1; @@ -144,4 +144,24 @@ static inline struct packet_sock *pkt_sk(struct sock *sk) return (struct packet_sock *)sk; } +enum packet_sock_flags { + PACKET_SOCK_ORIGDEV, +}; + +static inline void packet_sock_flag_set(struct packet_sock *po, + enum packet_sock_flags flag, + bool val) +{ + if (val) + set_bit(flag, &po->flags); + else + clear_bit(flag, &po->flags); +} + +static inline bool packet_sock_flag(const struct packet_sock *po, + enum packet_sock_flags flag) +{ + return test_bit(flag, &po->flags); +} + #endif -- cgit v1.2.3