[PATCH net 03/19] can: raw: add locking for raw flags bitfield
From: Marc Kleine-Budde <mkl@pengutronix.de>
Date: 2026-07-16 15:56:43
Also in:
linux-can
Subsystem:
can network layer, the rest · Maintainers:
Oliver Hartkopp, Marc Kleine-Budde, Linus Torvalds
From: Oliver Hartkopp <socketcan@hartkopp.net>
With commit 890e5198a6e5 ("can: raw: use bitfields to store flags in
struct raw_sock") the formerly separate integer values have been integrated
into a single bitfield. This led to a read-modify-write operation when
changing a flag in raw_setsockopt() which now needs a locking to prevent
concurrent access.
Instead of adding a lock/unlock hell in each of the flag manipulations this
patch introduces a wrapper for a new raw_setsockopt_locked() function
analogue to the isotp_setsockopt[_locked]() approach in net/can/isotp.c
Fixes: 890e5198a6e5 ("can: raw: use bitfields to store flags in struct raw_sock")
Reported-by: Eulgyu Kim <redacted>
Closes: https://lore.kernel.org/linux-can/20260503112200.22727-1-eulgyukim@snu.ac.kr/ (local)
Tested-by: Eulgyu Kim <redacted>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Reviewed-by: Vincent Mailhol <mailhol@kernel.org>
Tested-by: Vincent Mailhol <mailhol@kernel.org>
Link: https://patch.msgid.link/20260504111928.41856-1-socketcan@hartkopp.net
[mkl: use Closes tag instead of Link]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
net/can/raw.c | 66 +++++++++++++++++++++++----------------------------
1 file changed, 30 insertions(+), 36 deletions(-)
diff --git a/net/can/raw.c b/net/can/raw.c
index a26942e78e68..82d9c0499c95 100644
--- a/net/can/raw.c
+++ b/net/can/raw.c@@ -562,8 +562,8 @@ static int raw_getname(struct socket *sock, struct sockaddr *uaddr, return RAW_MIN_NAMELEN; } -static int raw_setsockopt(struct socket *sock, int level, int optname, - sockptr_t optval, unsigned int optlen) +static int raw_setsockopt_locked(struct socket *sock, int optname, + sockptr_t optval, unsigned int optlen) { struct sock *sk = sock->sk; struct raw_sock *ro = raw_sk(sk);
@@ -575,9 +575,6 @@ static int raw_setsockopt(struct socket *sock, int level, int optname, int flag; int err = 0; - if (level != SOL_CAN_RAW) - return -EINVAL; - switch (optname) { case CAN_RAW_FILTER: if (optlen % sizeof(struct can_filter) != 0)
@@ -598,17 +595,11 @@ static int raw_setsockopt(struct socket *sock, int level, int optname, return -EFAULT; } - rtnl_lock(); - lock_sock(sk); - dev = ro->dev; - if (ro->bound && dev) { - if (dev->reg_state != NETREG_REGISTERED) { - if (count > 1) - kfree(filter); - err = -ENODEV; - goto out_fil; - } + if (ro->bound && dev && dev->reg_state != NETREG_REGISTERED) { + if (count > 1) + kfree(filter); + return -ENODEV; } if (ro->bound) {
@@ -622,7 +613,7 @@ static int raw_setsockopt(struct socket *sock, int level, int optname, if (err) { if (count > 1) kfree(filter); - goto out_fil; + return err; } /* remove old filter registrations */
@@ -642,11 +633,6 @@ static int raw_setsockopt(struct socket *sock, int level, int optname, } ro->filter = filter; ro->count = count; - - out_fil: - release_sock(sk); - rtnl_unlock(); - break; case CAN_RAW_ERR_FILTER:
@@ -658,16 +644,9 @@ static int raw_setsockopt(struct socket *sock, int level, int optname, err_mask &= CAN_ERR_MASK; - rtnl_lock(); - lock_sock(sk); - dev = ro->dev; - if (ro->bound && dev) { - if (dev->reg_state != NETREG_REGISTERED) { - err = -ENODEV; - goto out_err; - } - } + if (ro->bound && dev && dev->reg_state != NETREG_REGISTERED) + return -ENODEV; /* remove current error mask */ if (ro->bound) {
@@ -676,7 +655,7 @@ static int raw_setsockopt(struct socket *sock, int level, int optname, err_mask); if (err) - goto out_err; + return err; /* remove old err_mask registration */ raw_disable_errfilter(sock_net(sk), dev, sk,
@@ -685,11 +664,6 @@ static int raw_setsockopt(struct socket *sock, int level, int optname, /* link new err_mask to the socket */ ro->err_mask = err_mask; - - out_err: - release_sock(sk); - rtnl_unlock(); - break; case CAN_RAW_LOOPBACK:
@@ -769,6 +743,26 @@ static int raw_setsockopt(struct socket *sock, int level, int optname, return err; } +static int raw_setsockopt(struct socket *sock, int level, int optname, + sockptr_t optval, unsigned int optlen) +{ + struct sock *sk = sock->sk; + int err; + + if (level != SOL_CAN_RAW) + return -EINVAL; + + rtnl_lock(); + lock_sock(sk); + + err = raw_setsockopt_locked(sock, optname, optval, optlen); + + release_sock(sk); + rtnl_unlock(); + + return err; +} + static int raw_getsockopt(struct socket *sock, int level, int optname, sockopt_t *opt) {
--
2.53.0