| Message ID | 20220301222822.19241-1-dossche.niels@gmail.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | f1fb205efb0ccca55626fd4ef38570dd16b44719 |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | sfc: extend the locking on mcdi->seqno | expand |
On Tue, Mar 01, 2022 at 11:28:22PM +0100, Niels Dossche wrote: > seqno could be read as a stale value outside of the lock. The lock is > already acquired to protect the modification of seqno against a possible > race condition. Place the reading of this value also inside this locking > to protect it against a possible race condition. > > Signed-off-by: Niels Dossche <dossche.niels@gmail.com> Acked-by: Martin Habets <habetsm.xilinx@gmail.com> > --- > drivers/net/ethernet/sfc/mcdi.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/net/ethernet/sfc/mcdi.c b/drivers/net/ethernet/sfc/mcdi.c > index be6bfd6b7ec7..50baf62b2cbc 100644 > --- a/drivers/net/ethernet/sfc/mcdi.c > +++ b/drivers/net/ethernet/sfc/mcdi.c > @@ -163,9 +163,9 @@ static void efx_mcdi_send_request(struct efx_nic *efx, unsigned cmd, > /* Serialise with efx_mcdi_ev_cpl() and efx_mcdi_ev_death() */ > spin_lock_bh(&mcdi->iface_lock); > ++mcdi->seqno; > + seqno = mcdi->seqno & SEQ_MASK; > spin_unlock_bh(&mcdi->iface_lock); > > - seqno = mcdi->seqno & SEQ_MASK; > xflags = 0; > if (mcdi->mode == MCDI_MODE_EVENTS) > xflags |= MCDI_HEADER_XFLAGS_EVREQ; > -- > 2.35.1
Hello: This patch was applied to netdev/net.git (master) by David S. Miller <davem@davemloft.net>: On Tue, 1 Mar 2022 23:28:22 +0100 you wrote: > seqno could be read as a stale value outside of the lock. The lock is > already acquired to protect the modification of seqno against a possible > race condition. Place the reading of this value also inside this locking > to protect it against a possible race condition. > > Signed-off-by: Niels Dossche <dossche.niels@gmail.com> > > [...] Here is the summary with links: - sfc: extend the locking on mcdi->seqno https://git.kernel.org/netdev/net/c/f1fb205efb0c You are awesome, thank you!
diff --git a/drivers/net/ethernet/sfc/mcdi.c b/drivers/net/ethernet/sfc/mcdi.c index be6bfd6b7ec7..50baf62b2cbc 100644 --- a/drivers/net/ethernet/sfc/mcdi.c +++ b/drivers/net/ethernet/sfc/mcdi.c @@ -163,9 +163,9 @@ static void efx_mcdi_send_request(struct efx_nic *efx, unsigned cmd, /* Serialise with efx_mcdi_ev_cpl() and efx_mcdi_ev_death() */ spin_lock_bh(&mcdi->iface_lock); ++mcdi->seqno; + seqno = mcdi->seqno & SEQ_MASK; spin_unlock_bh(&mcdi->iface_lock); - seqno = mcdi->seqno & SEQ_MASK; xflags = 0; if (mcdi->mode == MCDI_MODE_EVENTS) xflags |= MCDI_HEADER_XFLAGS_EVREQ;
seqno could be read as a stale value outside of the lock. The lock is already acquired to protect the modification of seqno against a possible race condition. Place the reading of this value also inside this locking to protect it against a possible race condition. Signed-off-by: Niels Dossche <dossche.niels@gmail.com> --- drivers/net/ethernet/sfc/mcdi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)