4.14-stable review patch. If anyone has any objections, please let me know.
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From: Jiri Pirko jiri@mellanox.com
[ Upstream commit 0f2d2b2736b08dafa3bde31d048750fbc8df3a31 ]
Since mlxsw_sp_fib_create() and mlxsw_sp_mr_table_create() use ERR_PTR macro to propagate int err through return of a pointer, the return value is not NULL in case of failure. So if one of the calls fails, one of vr->fib4, vr->fib6 or vr->mr4_table is not NULL and mlxsw_sp_vr_is_used wrongly assumes that vr is in use which leads to crash like following one:
[ 1293.949291] BUG: unable to handle kernel NULL pointer dereference at 00000000000006c9 [ 1293.952729] IP: mlxsw_sp_mr_table_flush+0x15/0x70 [mlxsw_spectrum]
Fix this by using local variables to hold the pointers and set vr->* only in case everything went fine.
Fixes: 76610ebbde18 ("mlxsw: spectrum_router: Refactor virtual router handling") Fixes: a3d9bc506d64 ("mlxsw: spectrum_router: Extend virtual routers with IPv6 support") Fixes: d42b0965b1d4 ("mlxsw: spectrum_router: Add multicast routes notification handling functionality") Signed-off-by: Jiri Pirko jiri@mellanox.com Reviewed-by: Ido Schimmel idosch@mellanox.com Signed-off-by: Jiri Pirko jiri@mellanox.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c | 19 ++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-)
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c +++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c @@ -729,26 +729,29 @@ static struct mlxsw_sp_fib *mlxsw_sp_vr_ static struct mlxsw_sp_vr *mlxsw_sp_vr_create(struct mlxsw_sp *mlxsw_sp, u32 tb_id) { + struct mlxsw_sp_fib *fib4; + struct mlxsw_sp_fib *fib6; struct mlxsw_sp_vr *vr; int err;
vr = mlxsw_sp_vr_find_unused(mlxsw_sp); if (!vr) return ERR_PTR(-EBUSY); - vr->fib4 = mlxsw_sp_fib_create(vr, MLXSW_SP_L3_PROTO_IPV4); - if (IS_ERR(vr->fib4)) - return ERR_CAST(vr->fib4); - vr->fib6 = mlxsw_sp_fib_create(vr, MLXSW_SP_L3_PROTO_IPV6); - if (IS_ERR(vr->fib6)) { - err = PTR_ERR(vr->fib6); + fib4 = mlxsw_sp_fib_create(vr, MLXSW_SP_L3_PROTO_IPV4); + if (IS_ERR(fib4)) + return ERR_CAST(fib4); + fib6 = mlxsw_sp_fib_create(vr, MLXSW_SP_L3_PROTO_IPV6); + if (IS_ERR(fib6)) { + err = PTR_ERR(fib6); goto err_fib6_create; } + vr->fib4 = fib4; + vr->fib6 = fib6; vr->tb_id = tb_id; return vr;
err_fib6_create: - mlxsw_sp_fib_destroy(vr->fib4); - vr->fib4 = NULL; + mlxsw_sp_fib_destroy(fib4); return ERR_PTR(err); }