- Linux-stable-mirror - lists.linaro.org

Patch "net: ethernet: ti: cpsw: fix net watchdog timeout" has been added to the 4.15-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled net: ethernet: ti: cpsw: fix net watchdog timeout to the 4.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: net-ethernet-ti-cpsw-fix-net-watchdog-timeout.patch and it can be found in the queue-4.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From foo@baz Tue Mar 6 19:02:56 PST 2018 From: Grygorii Strashko <grygorii.strashko(a)ti.com> Date: Tue, 6 Feb 2018 19:17:06 -0600 Subject: net: ethernet: ti: cpsw: fix net watchdog timeout From: Grygorii Strashko <grygorii.strashko(a)ti.com> [ Upstream commit 62f94c2101f35cd45775df00ba09bde77580e26a ] It was discovered that simple program which indefinitely sends 200b UDP packets and runs on TI AM574x SoC (SMP) under RT Kernel triggers network watchdog timeout in TI CPSW driver (<6 hours run). The network watchdog timeout is triggered due to race between cpsw_ndo_start_xmit() and cpsw_tx_handler() [NAPI] cpsw_ndo_start_xmit() if (unlikely(!cpdma_check_free_tx_desc(txch))) { txq = netdev_get_tx_queue(ndev, q_idx); netif_tx_stop_queue(txq); ^^ as per [1] barier has to be used after set_bit() otherwise new value might not be visible to other cpus } cpsw_tx_handler() if (unlikely(netif_tx_queue_stopped(txq))) netif_tx_wake_queue(txq); and when it happens ndev TX queue became disabled forever while driver's HW TX queue is empty. Fix this, by adding smp_mb__after_atomic() after netif_tx_stop_queue() calls and double check for free TX descriptors after stopping ndev TX queue - if there are free TX descriptors wake up ndev TX queue. [1] https://www.kernel.org/doc/html/latest/core-api/atomic_ops.html Signed-off-by: Grygorii Strashko <grygorii.strashko(a)ti.com> Reviewed-by: Ivan Khoronzhuk <ivan.khoronzhuk(a)linaro.org> Signed-off-by: David S. Miller <davem(a)davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- drivers/net/ethernet/ti/cpsw.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) --- a/drivers/net/ethernet/ti/cpsw.c +++ b/drivers/net/ethernet/ti/cpsw.c @@ -1618,6 +1618,7 @@ static netdev_tx_t cpsw_ndo_start_xmit(s q_idx = q_idx % cpsw->tx_ch_num; txch = cpsw->txv[q_idx].ch; + txq = netdev_get_tx_queue(ndev, q_idx); ret = cpsw_tx_packet_submit(priv, skb, txch); if (unlikely(ret != 0)) { cpsw_err(priv, tx_err, "desc submit failed\n"); @@ -1628,15 +1629,26 @@ static netdev_tx_t cpsw_ndo_start_xmit(s * tell the kernel to stop sending us tx frames. */ if (unlikely(!cpdma_check_free_tx_desc(txch))) { - txq = netdev_get_tx_queue(ndev, q_idx); netif_tx_stop_queue(txq); + + /* Barrier, so that stop_queue visible to other cpus */ + smp_mb__after_atomic(); + + if (cpdma_check_free_tx_desc(txch)) + netif_tx_wake_queue(txq); } return NETDEV_TX_OK; fail: ndev->stats.tx_dropped++; - txq = netdev_get_tx_queue(ndev, skb_get_queue_mapping(skb)); netif_tx_stop_queue(txq); + + /* Barrier, so that stop_queue visible to other cpus */ + smp_mb__after_atomic(); + + if (cpdma_check_free_tx_desc(txch)) + netif_tx_wake_queue(txq); + return NETDEV_TX_BUSY; } Patches currently in stable-queue which might be from grygorii.strashko(a)ti.com are queue-4.15/net-ethernet-ti-cpsw-fix-net-watchdog-timeout.patch

7 years, 4 months

1
0
0 0

Patch "net: fix race on decreasing number of TX queues" has been added to the 4.15-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled net: fix race on decreasing number of TX queues to the 4.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: net-fix-race-on-decreasing-number-of-tx-queues.patch and it can be found in the queue-4.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From foo@baz Tue Mar 6 19:02:56 PST 2018 From: Jakub Kicinski <jakub.kicinski(a)netronome.com> Date: Mon, 12 Feb 2018 21:35:31 -0800 Subject: net: fix race on decreasing number of TX queues From: Jakub Kicinski <jakub.kicinski(a)netronome.com> [ Upstream commit ac5b70198adc25c73fba28de4f78adcee8f6be0b ] netif_set_real_num_tx_queues() can be called when netdev is up. That usually happens when user requests change of number of channels/rings with ethtool -L. The procedure for changing the number of queues involves resetting the qdiscs and setting dev->num_tx_queues to the new value. When the new value is lower than the old one, extra care has to be taken to ensure ordering of accesses to the number of queues vs qdisc reset. Currently the queues are reset before new dev->num_tx_queues is assigned, leaving a window of time where packets can be enqueued onto the queues going down, leading to a likely crash in the drivers, since most drivers don't check if TX skbs are assigned to an active queue. Fixes: e6484930d7c7 ("net: allocate tx queues in register_netdevice") Signed-off-by: Jakub Kicinski <jakub.kicinski(a)netronome.com> Signed-off-by: David S. Miller <davem(a)davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- net/core/dev.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) --- a/net/core/dev.c +++ b/net/core/dev.c @@ -2366,8 +2366,11 @@ EXPORT_SYMBOL(netdev_set_num_tc); */ int netif_set_real_num_tx_queues(struct net_device *dev, unsigned int txq) { + bool disabling; int rc; + disabling = txq < dev->real_num_tx_queues; + if (txq < 1 || txq > dev->num_tx_queues) return -EINVAL; @@ -2383,15 +2386,19 @@ int netif_set_real_num_tx_queues(struct if (dev->num_tc) netif_setup_tc(dev, txq); - if (txq < dev->real_num_tx_queues) { + dev->real_num_tx_queues = txq; + + if (disabling) { + synchronize_net(); qdisc_reset_all_tx_gt(dev, txq); #ifdef CONFIG_XPS netif_reset_xps_queues_gt(dev, txq); #endif } + } else { + dev->real_num_tx_queues = txq; } - dev->real_num_tx_queues = txq; return 0; } EXPORT_SYMBOL(netif_set_real_num_tx_queues); Patches currently in stable-queue which might be from jakub.kicinski(a)netronome.com are queue-4.15/net-fix-race-on-decreasing-number-of-tx-queues.patch

7 years, 4 months

1
0
0 0

Patch "net: amd-xgbe: fix comparison to bitshift when dealing with a mask" has been added to the 4.15-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled net: amd-xgbe: fix comparison to bitshift when dealing with a mask to the 4.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: net-amd-xgbe-fix-comparison-to-bitshift-when-dealing-with-a-mask.patch and it can be found in the queue-4.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From foo@baz Tue Mar 6 19:02:56 PST 2018 From: Wolfram Sang <wsa+renesas(a)sang-engineering.com> Date: Mon, 5 Feb 2018 21:10:01 +0100 Subject: net: amd-xgbe: fix comparison to bitshift when dealing with a mask From: Wolfram Sang <wsa+renesas(a)sang-engineering.com> [ Upstream commit a3276892db7a588bedc33168e502572008f714a9 ] Due to a typo, the mask was destroyed by a comparison instead of a bit shift. Signed-off-by: Wolfram Sang <wsa+renesas(a)sang-engineering.com> Acked-by: Tom Lendacky <thomas.lendacky(a)amd.com> Signed-off-by: David S. Miller <davem(a)davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- drivers/net/ethernet/amd/xgbe/xgbe-drv.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/net/ethernet/amd/xgbe/xgbe-drv.c +++ b/drivers/net/ethernet/amd/xgbe/xgbe-drv.c @@ -595,7 +595,7 @@ isr_done: reissue_mask = 1 << 0; if (!pdata->per_channel_irq) - reissue_mask |= 0xffff < 4; + reissue_mask |= 0xffff << 4; XP_IOWRITE(pdata, XP_INT_REISSUE_EN, reissue_mask); } Patches currently in stable-queue which might be from wsa+renesas(a)sang-engineering.com are queue-4.15/net-amd-xgbe-fix-comparison-to-bitshift-when-dealing-with-a-mask.patch

7 years, 4 months

1
0
0 0

Patch "mlxsw: spectrum_switchdev: Check success of FDB add operation" has been added to the 4.15-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled mlxsw: spectrum_switchdev: Check success of FDB add operation to the 4.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: mlxsw-spectrum_switchdev-check-success-of-fdb-add-operation.patch and it can be found in the queue-4.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From foo@baz Tue Mar 6 19:02:56 PST 2018 From: Shalom Toledo <shalomt(a)mellanox.com> Date: Thu, 1 Mar 2018 11:37:05 +0100 Subject: mlxsw: spectrum_switchdev: Check success of FDB add operation From: Shalom Toledo <shalomt(a)mellanox.com> [ Upstream commit 0a8a1bf17e3af34f1f8d2368916a6327f8b3bfd5 ] Until now, we assumed that in case of error when adding FDB entries, the write operation will fail, but this is not the case. Instead, we need to check that the number of entries reported in the response is equal to the number of entries specified in the request. Fixes: 56ade8fe3fe1 ("mlxsw: spectrum: Add initial support for Spectrum ASIC") Reported-by: Ido Schimmel <idosch(a)mellanox.com> Signed-off-by: Shalom Toledo <shalomt(a)mellanox.com> Reviewed-by: Ido Schimmel <idosch(a)mellanox.com> Signed-off-by: Jiri Pirko <jiri(a)mellanox.com> Signed-off-by: David S. Miller <davem(a)davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c | 29 +++++++++++++-- 1 file changed, 27 insertions(+), 2 deletions(-) --- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c +++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c @@ -1203,6 +1203,7 @@ static int __mlxsw_sp_port_fdb_uc_op(str bool dynamic) { char *sfd_pl; + u8 num_rec; int err; sfd_pl = kmalloc(MLXSW_REG_SFD_LEN, GFP_KERNEL); @@ -1212,9 +1213,16 @@ static int __mlxsw_sp_port_fdb_uc_op(str mlxsw_reg_sfd_pack(sfd_pl, mlxsw_sp_sfd_op(adding), 0); mlxsw_reg_sfd_uc_pack(sfd_pl, 0, mlxsw_sp_sfd_rec_policy(dynamic), mac, fid, action, local_port); + num_rec = mlxsw_reg_sfd_num_rec_get(sfd_pl); err = mlxsw_reg_write(mlxsw_sp->core, MLXSW_REG(sfd), sfd_pl); - kfree(sfd_pl); + if (err) + goto out; + + if (num_rec != mlxsw_reg_sfd_num_rec_get(sfd_pl)) + err = -EBUSY; +out: + kfree(sfd_pl); return err; } @@ -1239,6 +1247,7 @@ static int mlxsw_sp_port_fdb_uc_lag_op(s bool adding, bool dynamic) { char *sfd_pl; + u8 num_rec; int err; sfd_pl = kmalloc(MLXSW_REG_SFD_LEN, GFP_KERNEL); @@ -1249,9 +1258,16 @@ static int mlxsw_sp_port_fdb_uc_lag_op(s mlxsw_reg_sfd_uc_lag_pack(sfd_pl, 0, mlxsw_sp_sfd_rec_policy(dynamic), mac, fid, MLXSW_REG_SFD_REC_ACTION_NOP, lag_vid, lag_id); + num_rec = mlxsw_reg_sfd_num_rec_get(sfd_pl); err = mlxsw_reg_write(mlxsw_sp->core, MLXSW_REG(sfd), sfd_pl); - kfree(sfd_pl); + if (err) + goto out; + if (num_rec != mlxsw_reg_sfd_num_rec_get(sfd_pl)) + err = -EBUSY; + +out: + kfree(sfd_pl); return err; } @@ -1296,6 +1312,7 @@ static int mlxsw_sp_port_mdb_op(struct m u16 fid, u16 mid_idx, bool adding) { char *sfd_pl; + u8 num_rec; int err; sfd_pl = kmalloc(MLXSW_REG_SFD_LEN, GFP_KERNEL); @@ -1305,7 +1322,15 @@ static int mlxsw_sp_port_mdb_op(struct m mlxsw_reg_sfd_pack(sfd_pl, mlxsw_sp_sfd_op(adding), 0); mlxsw_reg_sfd_mc_pack(sfd_pl, 0, addr, fid, MLXSW_REG_SFD_REC_ACTION_NOP, mid_idx); + num_rec = mlxsw_reg_sfd_num_rec_get(sfd_pl); err = mlxsw_reg_write(mlxsw_sp->core, MLXSW_REG(sfd), sfd_pl); + if (err) + goto out; + + if (num_rec != mlxsw_reg_sfd_num_rec_get(sfd_pl)) + err = -EBUSY; + +out: kfree(sfd_pl); return err; } Patches currently in stable-queue which might be from shalomt(a)mellanox.com are queue-4.15/mlxsw-spectrum_switchdev-check-success-of-fdb-add-operation.patch

7 years, 4 months

1
0
0 0

Patch "mlxsw: spectrum_router: Fix error path in mlxsw_sp_vr_create" has been added to the 4.15-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled mlxsw: spectrum_router: Fix error path in mlxsw_sp_vr_create to the 4.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: mlxsw-spectrum_router-fix-error-path-in-mlxsw_sp_vr_create.patch and it can be found in the queue-4.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From foo@baz Tue Mar 6 19:02:56 PST 2018 From: Jiri Pirko <jiri(a)mellanox.com> Date: Tue, 13 Feb 2018 11:22:42 +0100 Subject: mlxsw: spectrum_router: Fix error path in mlxsw_sp_vr_create From: Jiri Pirko <jiri(a)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(a)mellanox.com> Reviewed-by: Ido Schimmel <idosch(a)mellanox.com> Signed-off-by: Jiri Pirko <jiri(a)mellanox.com> Signed-off-by: David S. Miller <davem(a)davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c | 32 ++++++++++-------- 1 file changed, 18 insertions(+), 14 deletions(-) --- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c +++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c @@ -737,6 +737,9 @@ static struct mlxsw_sp_vr *mlxsw_sp_vr_c u32 tb_id, struct netlink_ext_ack *extack) { + struct mlxsw_sp_mr_table *mr4_table; + struct mlxsw_sp_fib *fib4; + struct mlxsw_sp_fib *fib6; struct mlxsw_sp_vr *vr; int err; @@ -745,29 +748,30 @@ static struct mlxsw_sp_vr *mlxsw_sp_vr_c NL_SET_ERR_MSG(extack, "spectrum: Exceeded number of supported virtual routers"); 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->mr4_table = mlxsw_sp_mr_table_create(mlxsw_sp, vr->id, - MLXSW_SP_L3_PROTO_IPV4); - if (IS_ERR(vr->mr4_table)) { - err = PTR_ERR(vr->mr4_table); + mr4_table = mlxsw_sp_mr_table_create(mlxsw_sp, vr->id, + MLXSW_SP_L3_PROTO_IPV4); + if (IS_ERR(mr4_table)) { + err = PTR_ERR(mr4_table); goto err_mr_table_create; } + vr->fib4 = fib4; + vr->fib6 = fib6; + vr->mr4_table = mr4_table; vr->tb_id = tb_id; return vr; err_mr_table_create: - mlxsw_sp_fib_destroy(vr->fib6); - vr->fib6 = NULL; + mlxsw_sp_fib_destroy(fib6); err_fib6_create: - mlxsw_sp_fib_destroy(vr->fib4); - vr->fib4 = NULL; + mlxsw_sp_fib_destroy(fib4); return ERR_PTR(err); } Patches currently in stable-queue which might be from jiri(a)mellanox.com are queue-4.15/mlxsw-spectrum_router-fix-error-path-in-mlxsw_sp_vr_create.patch queue-4.15/mlxsw-spectrum_router-do-not-unconditionally-clear-route-offload-indication.patch queue-4.15/net-sched-report-if-filter-is-too-large-to-dump.patch queue-4.15/mlxsw-spectrum_switchdev-check-success-of-fdb-add-operation.patch

7 years, 4 months

1
0
0 0

Patch "mlxsw: spectrum_router: Do not unconditionally clear route offload indication" has been added to the 4.15-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled mlxsw: spectrum_router: Do not unconditionally clear route offload indication to the 4.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: mlxsw-spectrum_router-do-not-unconditionally-clear-route-offload-indication.patch and it can be found in the queue-4.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From foo@baz Tue Mar 6 19:02:56 PST 2018 From: Ido Schimmel <idosch(a)mellanox.com> Date: Sat, 17 Feb 2018 00:30:44 +0100 Subject: mlxsw: spectrum_router: Do not unconditionally clear route offload indication From: Ido Schimmel <idosch(a)mellanox.com> [ Upstream commit d1c95af366961101819f07e3c64d44f3be7f0367 ] When mlxsw replaces (or deletes) a route it removes the offload indication from the replaced route. This is problematic for IPv4 routes, as the offload indication is stored in the fib_info which is usually shared between multiple routes. Instead of unconditionally clearing the offload indication, only clear it if no other route is using the fib_info. Fixes: 3984d1a89fe7 ("mlxsw: spectrum_router: Provide offload indication using nexthop flags") Signed-off-by: Ido Schimmel <idosch(a)mellanox.com> Reported-by: Alexander Petrovskiy <alexpe(a)mellanox.com> Tested-by: Alexander Petrovskiy <alexpe(a)mellanox.com> Signed-off-by: Jiri Pirko <jiri(a)mellanox.com> Signed-off-by: David S. Miller <davem(a)davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c | 3 +++ 1 file changed, 3 insertions(+) --- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c +++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c @@ -3765,6 +3765,9 @@ mlxsw_sp_fib4_entry_offload_unset(struct struct mlxsw_sp_nexthop_group *nh_grp = fib_entry->nh_group; int i; + if (!list_is_singular(&nh_grp->fib_list)) + return; + for (i = 0; i < nh_grp->count; i++) { struct mlxsw_sp_nexthop *nh = &nh_grp->nexthops[i]; Patches currently in stable-queue which might be from idosch(a)mellanox.com are queue-4.15/mlxsw-spectrum_router-fix-error-path-in-mlxsw_sp_vr_create.patch queue-4.15/mlxsw-spectrum_router-do-not-unconditionally-clear-route-offload-indication.patch queue-4.15/bridge-fix-vlan-reference-count-problem.patch queue-4.15/net-ipv4-set-addr_type-in-hash_keys-for-forwarded-case.patch queue-4.15/mlxsw-spectrum_switchdev-check-success-of-fdb-add-operation.patch

7 years, 4 months

1
0
0 0

Patch "l2tp: fix tunnel lookup use-after-free race" has been added to the 4.15-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled l2tp: fix tunnel lookup use-after-free race to the 4.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: l2tp-fix-tunnel-lookup-use-after-free-race.patch and it can be found in the queue-4.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From foo@baz Tue Mar 6 19:02:57 PST 2018 From: James Chapman <jchapman(a)katalix.com> Date: Fri, 23 Feb 2018 17:45:47 +0000 Subject: l2tp: fix tunnel lookup use-after-free race From: James Chapman <jchapman(a)katalix.com> [ Upstream commit 28f5bfb819195ad9c2eb9486babe7b0e4efe925f ] l2tp_tunnel_get walks the tunnel list to find a matching tunnel instance and if a match is found, its refcount is increased before returning the tunnel pointer. But when tunnel objects are destroyed, they are on the tunnel list after their refcount hits zero. Fix this by moving the code that removes the tunnel from the tunnel list from the tunnel socket destructor into in the l2tp_tunnel_delete path, before the tunnel refcount is decremented. refcount_t: increment on 0; use-after-free. WARNING: CPU: 3 PID: 13507 at lib/refcount.c:153 refcount_inc+0x47/0x50 Modules linked in: CPU: 3 PID: 13507 Comm: syzbot_6e6a5ec8 Not tainted 4.16.0-rc2+ #36 Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 RIP: 0010:refcount_inc+0x47/0x50 RSP: 0018:ffff8800136ffb20 EFLAGS: 00010286 RAX: dffffc0000000008 RBX: ffff880017068e68 RCX: ffffffff814d3333 RDX: 0000000000000000 RSI: ffff88001a59f6d8 RDI: ffff88001a59f6d8 RBP: ffff8800136ffb28 R08: 0000000000000000 R09: 0000000000000000 R10: ffff8800136ffab0 R11: 0000000000000000 R12: ffff880017068e50 R13: 0000000000000000 R14: ffff8800174da800 R15: 0000000000000004 FS: 00007f403ab1e700(0000) GS:ffff88001a580000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000205fafd2 CR3: 0000000016770000 CR4: 00000000000006e0 Call Trace: l2tp_tunnel_get+0x2dd/0x4e0 pppol2tp_connect+0x428/0x13c0 ? pppol2tp_session_create+0x170/0x170 ? __might_fault+0x115/0x1d0 ? lock_downgrade+0x860/0x860 ? __might_fault+0xe5/0x1d0 ? security_socket_connect+0x8e/0xc0 SYSC_connect+0x1b6/0x310 ? SYSC_bind+0x280/0x280 ? __do_page_fault+0x5d1/0xca0 ? up_read+0x1f/0x40 ? __do_page_fault+0x3c8/0xca0 SyS_connect+0x29/0x30 ? SyS_accept+0x40/0x40 do_syscall_64+0x1e0/0x730 ? trace_hardirqs_off_thunk+0x1a/0x1c entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x7f403a42f259 RSP: 002b:00007f403ab1dee8 EFLAGS: 00000296 ORIG_RAX: 000000000000002a RAX: ffffffffffffffda RBX: 00000000205fafe4 RCX: 00007f403a42f259 RDX: 000000000000002e RSI: 00000000205fafd2 RDI: 0000000000000004 RBP: 00007f403ab1df20 R08: 00007f403ab1e700 R09: 0000000000000000 R10: 00007f403ab1e700 R11: 0000000000000296 R12: 0000000000000000 R13: 00007ffc81906cbf R14: 0000000000000000 R15: 00007f403ab2b040 Code: 3b ff 5b 5d c3 e8 ca 5f 3b ff 80 3d 49 8e 66 04 00 75 ea e8 bc 5f 3b ff 48 c7 c7 60 69 64 85 c6 05 34 8e 66 04 01 e8 59 49 15 ff <0f> 0b eb ce 0f 1f 44 00 00 55 48 89 e5 41 56 41 55 41 54 53 49 Fixes: f8ccac0e44934 ("l2tp: put tunnel socket release on a workqueue") Reported-and-tested-by: syzbot+19c09769f14b48810113(a)syzkaller.appspotmail.com Reported-and-tested-by: syzbot+347bd5acde002e353a36(a)syzkaller.appspotmail.com Reported-and-tested-by: syzbot+6e6a5ec8de31a94cd015(a)syzkaller.appspotmail.com Reported-and-tested-by: syzbot+9df43faf09bd400f2993(a)syzkaller.appspotmail.com Signed-off-by: James Chapman <jchapman(a)katalix.com> Signed-off-by: David S. Miller <davem(a)davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- net/l2tp/l2tp_core.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) --- a/net/l2tp/l2tp_core.c +++ b/net/l2tp/l2tp_core.c @@ -1173,7 +1173,6 @@ EXPORT_SYMBOL_GPL(l2tp_xmit_skb); static void l2tp_tunnel_destruct(struct sock *sk) { struct l2tp_tunnel *tunnel = l2tp_tunnel(sk); - struct l2tp_net *pn; if (tunnel == NULL) goto end; @@ -1196,12 +1195,6 @@ static void l2tp_tunnel_destruct(struct sk->sk_destruct = tunnel->old_sk_destruct; sk->sk_user_data = NULL; - /* Remove the tunnel struct from the tunnel list */ - pn = l2tp_pernet(tunnel->l2tp_net); - spin_lock_bh(&pn->l2tp_tunnel_list_lock); - list_del_rcu(&tunnel->list); - spin_unlock_bh(&pn->l2tp_tunnel_list_lock); - /* Call the original destructor */ if (sk->sk_destruct) (*sk->sk_destruct)(sk); @@ -1280,6 +1273,7 @@ static void l2tp_tunnel_del_work(struct del_work); struct sock *sk = tunnel->sock; struct socket *sock = sk->sk_socket; + struct l2tp_net *pn; l2tp_tunnel_closeall(tunnel); @@ -1293,6 +1287,12 @@ static void l2tp_tunnel_del_work(struct } } + /* Remove the tunnel struct from the tunnel list */ + pn = l2tp_pernet(tunnel->l2tp_net); + spin_lock_bh(&pn->l2tp_tunnel_list_lock); + list_del_rcu(&tunnel->list); + spin_unlock_bh(&pn->l2tp_tunnel_list_lock); + /* drop initial ref */ l2tp_tunnel_dec_refcount(tunnel); Patches currently in stable-queue which might be from jchapman(a)katalix.com are queue-4.15/l2tp-don-t-use-inet_shutdown-on-tunnel-destroy.patch queue-4.15/l2tp-don-t-use-inet_shutdown-on-ppp-session-destroy.patch queue-4.15/l2tp-fix-races-with-tunnel-socket-close.patch queue-4.15/l2tp-fix-race-in-pppol2tp_release-with-session-object-destroy.patch queue-4.15/l2tp-fix-tunnel-lookup-use-after-free-race.patch

7 years, 4 months

1
0
0 0

Patch "l2tp: fix races with tunnel socket close" has been added to the 4.15-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled l2tp: fix races with tunnel socket close to the 4.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: l2tp-fix-races-with-tunnel-socket-close.patch and it can be found in the queue-4.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From foo@baz Tue Mar 6 19:02:57 PST 2018 From: James Chapman <jchapman(a)katalix.com> Date: Fri, 23 Feb 2018 17:45:45 +0000 Subject: l2tp: fix races with tunnel socket close From: James Chapman <jchapman(a)katalix.com> [ Upstream commit d00fa9adc528c1b0e64d532556764852df8bd7b9 ] The tunnel socket tunnel->sock (struct sock) is accessed when preparing a new ppp session on a tunnel at pppol2tp_session_init. If the socket is closed by a thread while another is creating a new session, the threads race. In pppol2tp_connect, the tunnel object may be created if the pppol2tp socket is associated with the special session_id 0 and the tunnel socket is looked up using the provided fd. When handling this, pppol2tp_connect cannot sock_hold the tunnel socket to prevent it being destroyed during pppol2tp_connect since this may itself may race with the socket being destroyed. Doing sockfd_lookup in pppol2tp_connect isn't sufficient to prevent tunnel->sock going away either because a given tunnel socket fd may be reused between calls to pppol2tp_connect. Instead, have l2tp_tunnel_create sock_hold the tunnel socket before it does sockfd_put. This ensures that the tunnel's socket is always extant while the tunnel object exists. Hold a ref on the socket until the tunnel is destroyed and ensure that all tunnel destroy paths go through a common function (l2tp_tunnel_delete) since this will do the final sock_put to release the tunnel socket. Since the tunnel's socket is now guaranteed to exist if the tunnel exists, we no longer need to use sockfd_lookup via l2tp_sock_to_tunnel to derive the tunnel from the socket since this is always sk_user_data. Also, sessions no longer sock_hold the tunnel socket since sessions already hold a tunnel ref and the tunnel sock will not be freed until the tunnel is freed. Removing these sock_holds in l2tp_session_register avoids a possible sock leak in the pppol2tp_connect error path if l2tp_session_register succeeds but attaching a ppp channel fails. The pppol2tp_connect error path could have been fixed instead and have the sock ref dropped when the session is freed, but doing a sock_put of the tunnel socket when the session is freed would require a new session_free callback. It is simpler to just remove the sock_hold of the tunnel socket in l2tp_session_register, now that the tunnel socket lifetime is guaranteed. Finally, some init code in l2tp_tunnel_create is reordered to ensure that the new tunnel object's refcount is set and the tunnel socket ref is taken before the tunnel socket destructor callbacks are set. kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] SMP KASAN Modules linked in: CPU: 0 PID: 4360 Comm: syzbot_19c09769 Not tainted 4.16.0-rc2+ #34 Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 RIP: 0010:pppol2tp_session_init+0x1d6/0x500 RSP: 0018:ffff88001377fb40 EFLAGS: 00010212 RAX: dffffc0000000000 RBX: ffff88001636a940 RCX: ffffffff84836c1d RDX: 0000000000000045 RSI: 0000000055976744 RDI: 0000000000000228 RBP: ffff88001377fb60 R08: ffffffff84836bc8 R09: 0000000000000002 R10: ffff88001377fab8 R11: 0000000000000001 R12: 0000000000000000 R13: ffff88001636aac8 R14: ffff8800160f81c0 R15: 1ffff100026eff76 FS: 00007ffb3ea66700(0000) GS:ffff88001a400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020e77000 CR3: 0000000016261000 CR4: 00000000000006f0 Call Trace: pppol2tp_connect+0xd18/0x13c0 ? pppol2tp_session_create+0x170/0x170 ? __might_fault+0x115/0x1d0 ? lock_downgrade+0x860/0x860 ? __might_fault+0xe5/0x1d0 ? security_socket_connect+0x8e/0xc0 SYSC_connect+0x1b6/0x310 ? SYSC_bind+0x280/0x280 ? __do_page_fault+0x5d1/0xca0 ? up_read+0x1f/0x40 ? __do_page_fault+0x3c8/0xca0 SyS_connect+0x29/0x30 ? SyS_accept+0x40/0x40 do_syscall_64+0x1e0/0x730 ? trace_hardirqs_off_thunk+0x1a/0x1c entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x7ffb3e376259 RSP: 002b:00007ffeda4f6508 EFLAGS: 00000202 ORIG_RAX: 000000000000002a RAX: ffffffffffffffda RBX: 0000000020e77012 RCX: 00007ffb3e376259 RDX: 000000000000002e RSI: 0000000020e77000 RDI: 0000000000000004 RBP: 00007ffeda4f6540 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000400b60 R13: 00007ffeda4f6660 R14: 0000000000000000 R15: 0000000000000000 Code: 80 3d b0 ff 06 02 00 0f 84 07 02 00 00 e8 13 d6 db fc 49 8d bc 24 28 02 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 f a 48 c1 ea 03 <80> 3c 02 00 0f 85 ed 02 00 00 4d 8b a4 24 28 02 00 00 e8 13 16 Fixes: 80d84ef3ff1dd ("l2tp: prevent l2tp_tunnel_delete racing with userspace close") Signed-off-by: James Chapman <jchapman(a)katalix.com> Signed-off-by: David S. Miller <davem(a)davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- net/l2tp/l2tp_core.c | 117 ++++++++++++++------------------------------------- net/l2tp/l2tp_core.h | 23 ---------- net/l2tp/l2tp_ip.c | 10 +--- net/l2tp/l2tp_ip6.c | 8 +-- 4 files changed, 42 insertions(+), 116 deletions(-) --- a/net/l2tp/l2tp_core.c +++ b/net/l2tp/l2tp_core.c @@ -136,51 +136,6 @@ l2tp_session_id_hash_2(struct l2tp_net * } -/* Lookup the tunnel socket, possibly involving the fs code if the socket is - * owned by userspace. A struct sock returned from this function must be - * released using l2tp_tunnel_sock_put once you're done with it. - */ -static struct sock *l2tp_tunnel_sock_lookup(struct l2tp_tunnel *tunnel) -{ - int err = 0; - struct socket *sock = NULL; - struct sock *sk = NULL; - - if (!tunnel) - goto out; - - if (tunnel->fd >= 0) { - /* Socket is owned by userspace, who might be in the process - * of closing it. Look the socket up using the fd to ensure - * consistency. - */ - sock = sockfd_lookup(tunnel->fd, &err); - if (sock) - sk = sock->sk; - } else { - /* Socket is owned by kernelspace */ - sk = tunnel->sock; - sock_hold(sk); - } - -out: - return sk; -} - -/* Drop a reference to a tunnel socket obtained via. l2tp_tunnel_sock_put */ -static void l2tp_tunnel_sock_put(struct sock *sk) -{ - struct l2tp_tunnel *tunnel = l2tp_sock_to_tunnel(sk); - if (tunnel) { - if (tunnel->fd >= 0) { - /* Socket is owned by userspace */ - sockfd_put(sk->sk_socket); - } - sock_put(sk); - } - sock_put(sk); -} - /* Session hash list. * The session_id SHOULD be random according to RFC2661, but several * L2TP implementations (Cisco and Microsoft) use incrementing @@ -193,6 +148,13 @@ l2tp_session_id_hash(struct l2tp_tunnel return &tunnel->session_hlist[hash_32(session_id, L2TP_HASH_BITS)]; } +void l2tp_tunnel_free(struct l2tp_tunnel *tunnel) +{ + sock_put(tunnel->sock); + /* the tunnel is freed in the socket destructor */ +} +EXPORT_SYMBOL(l2tp_tunnel_free); + /* Lookup a tunnel. A new reference is held on the returned tunnel. */ struct l2tp_tunnel *l2tp_tunnel_get(const struct net *net, u32 tunnel_id) { @@ -345,13 +307,11 @@ int l2tp_session_register(struct l2tp_se } l2tp_tunnel_inc_refcount(tunnel); - sock_hold(tunnel->sock); hlist_add_head_rcu(&session->global_hlist, g_head); spin_unlock_bh(&pn->l2tp_session_hlist_lock); } else { l2tp_tunnel_inc_refcount(tunnel); - sock_hold(tunnel->sock); } hlist_add_head(&session->hlist, head); @@ -975,7 +935,7 @@ int l2tp_udp_encap_recv(struct sock *sk, { struct l2tp_tunnel *tunnel; - tunnel = l2tp_sock_to_tunnel(sk); + tunnel = l2tp_tunnel(sk); if (tunnel == NULL) goto pass_up; @@ -983,13 +943,10 @@ int l2tp_udp_encap_recv(struct sock *sk, tunnel->name, skb->len); if (l2tp_udp_recv_core(tunnel, skb, tunnel->recv_payload_hook)) - goto pass_up_put; + goto pass_up; - sock_put(sk); return 0; -pass_up_put: - sock_put(sk); pass_up: return 1; } @@ -1223,7 +1180,6 @@ static void l2tp_tunnel_destruct(struct l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: closing...\n", tunnel->name); - /* Disable udp encapsulation */ switch (tunnel->encap) { case L2TP_ENCAPTYPE_UDP: @@ -1246,12 +1202,11 @@ static void l2tp_tunnel_destruct(struct list_del_rcu(&tunnel->list); spin_unlock_bh(&pn->l2tp_tunnel_list_lock); - tunnel->sock = NULL; - l2tp_tunnel_dec_refcount(tunnel); - /* Call the original destructor */ if (sk->sk_destruct) (*sk->sk_destruct)(sk); + + kfree_rcu(tunnel, rcu); end: return; } @@ -1312,30 +1267,22 @@ EXPORT_SYMBOL_GPL(l2tp_tunnel_closeall); /* Tunnel socket destroy hook for UDP encapsulation */ static void l2tp_udp_encap_destroy(struct sock *sk) { - struct l2tp_tunnel *tunnel = l2tp_sock_to_tunnel(sk); - if (tunnel) { - l2tp_tunnel_closeall(tunnel); - sock_put(sk); - } + struct l2tp_tunnel *tunnel = l2tp_tunnel(sk); + + if (tunnel) + l2tp_tunnel_delete(tunnel); } /* Workqueue tunnel deletion function */ static void l2tp_tunnel_del_work(struct work_struct *work) { - struct l2tp_tunnel *tunnel = NULL; - struct socket *sock = NULL; - struct sock *sk = NULL; - - tunnel = container_of(work, struct l2tp_tunnel, del_work); + struct l2tp_tunnel *tunnel = container_of(work, struct l2tp_tunnel, + del_work); + struct sock *sk = tunnel->sock; + struct socket *sock = sk->sk_socket; l2tp_tunnel_closeall(tunnel); - sk = l2tp_tunnel_sock_lookup(tunnel); - if (!sk) - goto out; - - sock = sk->sk_socket; - /* If the tunnel socket was created within the kernel, use * the sk API to release it here. */ @@ -1346,8 +1293,10 @@ static void l2tp_tunnel_del_work(struct } } - l2tp_tunnel_sock_put(sk); -out: + /* drop initial ref */ + l2tp_tunnel_dec_refcount(tunnel); + + /* drop workqueue ref */ l2tp_tunnel_dec_refcount(tunnel); } @@ -1600,13 +1549,22 @@ int l2tp_tunnel_create(struct net *net, sk->sk_user_data = tunnel; } + /* Bump the reference count. The tunnel context is deleted + * only when this drops to zero. A reference is also held on + * the tunnel socket to ensure that it is not released while + * the tunnel is extant. Must be done before sk_destruct is + * set. + */ + refcount_set(&tunnel->ref_count, 1); + sock_hold(sk); + tunnel->sock = sk; + tunnel->fd = fd; + /* Hook on the tunnel socket destructor so that we can cleanup * if the tunnel socket goes away. */ tunnel->old_sk_destruct = sk->sk_destruct; sk->sk_destruct = &l2tp_tunnel_destruct; - tunnel->sock = sk; - tunnel->fd = fd; lockdep_set_class_and_name(&sk->sk_lock.slock, &l2tp_socket_class, "l2tp_sock"); sk->sk_allocation = GFP_ATOMIC; @@ -1616,11 +1574,6 @@ int l2tp_tunnel_create(struct net *net, /* Add tunnel to our list */ INIT_LIST_HEAD(&tunnel->list); - - /* Bump the reference count. The tunnel context is deleted - * only when this drops to zero. Must be done before list insertion - */ - refcount_set(&tunnel->ref_count, 1); spin_lock_bh(&pn->l2tp_tunnel_list_lock); list_add_rcu(&tunnel->list, &pn->l2tp_tunnel_list); spin_unlock_bh(&pn->l2tp_tunnel_list_lock); @@ -1661,8 +1614,6 @@ void l2tp_session_free(struct l2tp_sessi if (tunnel) { BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC); - sock_put(tunnel->sock); - session->tunnel = NULL; l2tp_tunnel_dec_refcount(tunnel); } --- a/net/l2tp/l2tp_core.h +++ b/net/l2tp/l2tp_core.h @@ -219,27 +219,8 @@ static inline void *l2tp_session_priv(st return &session->priv[0]; } -static inline struct l2tp_tunnel *l2tp_sock_to_tunnel(struct sock *sk) -{ - struct l2tp_tunnel *tunnel; - - if (sk == NULL) - return NULL; - - sock_hold(sk); - tunnel = (struct l2tp_tunnel *)(sk->sk_user_data); - if (tunnel == NULL) { - sock_put(sk); - goto out; - } - - BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC); - -out: - return tunnel; -} - struct l2tp_tunnel *l2tp_tunnel_get(const struct net *net, u32 tunnel_id); +void l2tp_tunnel_free(struct l2tp_tunnel *tunnel); struct l2tp_session *l2tp_session_get(const struct net *net, struct l2tp_tunnel *tunnel, @@ -288,7 +269,7 @@ static inline void l2tp_tunnel_inc_refco static inline void l2tp_tunnel_dec_refcount(struct l2tp_tunnel *tunnel) { if (refcount_dec_and_test(&tunnel->ref_count)) - kfree_rcu(tunnel, rcu); + l2tp_tunnel_free(tunnel); } /* Session reference counts. Incremented when code obtains a reference --- a/net/l2tp/l2tp_ip.c +++ b/net/l2tp/l2tp_ip.c @@ -234,17 +234,13 @@ static void l2tp_ip_close(struct sock *s static void l2tp_ip_destroy_sock(struct sock *sk) { struct sk_buff *skb; - struct l2tp_tunnel *tunnel = l2tp_sock_to_tunnel(sk); + struct l2tp_tunnel *tunnel = sk->sk_user_data; while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL) kfree_skb(skb); - if (tunnel) { - l2tp_tunnel_closeall(tunnel); - sock_put(sk); - } - - sk_refcnt_debug_dec(sk); + if (tunnel) + l2tp_tunnel_delete(tunnel); } static int l2tp_ip_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) --- a/net/l2tp/l2tp_ip6.c +++ b/net/l2tp/l2tp_ip6.c @@ -248,16 +248,14 @@ static void l2tp_ip6_close(struct sock * static void l2tp_ip6_destroy_sock(struct sock *sk) { - struct l2tp_tunnel *tunnel = l2tp_sock_to_tunnel(sk); + struct l2tp_tunnel *tunnel = sk->sk_user_data; lock_sock(sk); ip6_flush_pending_frames(sk); release_sock(sk); - if (tunnel) { - l2tp_tunnel_closeall(tunnel); - sock_put(sk); - } + if (tunnel) + l2tp_tunnel_delete(tunnel); inet6_destroy_sock(sk); } Patches currently in stable-queue which might be from jchapman(a)katalix.com are queue-4.15/l2tp-don-t-use-inet_shutdown-on-tunnel-destroy.patch queue-4.15/l2tp-don-t-use-inet_shutdown-on-ppp-session-destroy.patch queue-4.15/l2tp-fix-races-with-tunnel-socket-close.patch queue-4.15/l2tp-fix-race-in-pppol2tp_release-with-session-object-destroy.patch queue-4.15/l2tp-fix-tunnel-lookup-use-after-free-race.patch

7 years, 4 months

1
0
0 0

Patch "l2tp: fix race in pppol2tp_release with session object destroy" has been added to the 4.15-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled l2tp: fix race in pppol2tp_release with session object destroy to the 4.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: l2tp-fix-race-in-pppol2tp_release-with-session-object-destroy.patch and it can be found in the queue-4.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From foo@baz Tue Mar 6 19:02:57 PST 2018 From: James Chapman <jchapman(a)katalix.com> Date: Fri, 23 Feb 2018 17:45:46 +0000 Subject: l2tp: fix race in pppol2tp_release with session object destroy From: James Chapman <jchapman(a)katalix.com> [ Upstream commit d02ba2a6110c530a32926af8ad441111774d2893 ] pppol2tp_release uses call_rcu to put the final ref on its socket. But the session object doesn't hold a ref on the session socket so may be freed while the pppol2tp_put_sk RCU callback is scheduled. Fix this by having the session hold a ref on its socket until the session is destroyed. It is this ref that is dropped via call_rcu. Sessions are also deleted via l2tp_tunnel_closeall. This must now also put the final ref via call_rcu. So move the call_rcu call site into pppol2tp_session_close so that this happens in both destroy paths. A common destroy path should really be implemented, perhaps with l2tp_tunnel_closeall calling l2tp_session_delete like pppol2tp_release does, but this will be looked at later. ODEBUG: activate active (active state 1) object type: rcu_head hint: (null) WARNING: CPU: 3 PID: 13407 at lib/debugobjects.c:291 debug_print_object+0x166/0x220 Modules linked in: CPU: 3 PID: 13407 Comm: syzbot_19c09769 Not tainted 4.16.0-rc2+ #38 Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 RIP: 0010:debug_print_object+0x166/0x220 RSP: 0018:ffff880013647a00 EFLAGS: 00010082 RAX: dffffc0000000008 RBX: 0000000000000003 RCX: ffffffff814d3333 RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff88001a59f6d0 RBP: ffff880013647a40 R08: 0000000000000000 R09: 0000000000000001 R10: ffff8800136479a8 R11: 0000000000000000 R12: 0000000000000001 R13: ffffffff86161420 R14: ffffffff85648b60 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88001a580000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020e77000 CR3: 0000000006022000 CR4: 00000000000006e0 Call Trace: debug_object_activate+0x38b/0x530 ? debug_object_assert_init+0x3b0/0x3b0 ? __mutex_unlock_slowpath+0x85/0x8b0 ? pppol2tp_session_destruct+0x110/0x110 __call_rcu.constprop.66+0x39/0x890 ? __call_rcu.constprop.66+0x39/0x890 call_rcu_sched+0x17/0x20 pppol2tp_release+0x2c7/0x440 ? fcntl_setlk+0xca0/0xca0 ? sock_alloc_file+0x340/0x340 sock_release+0x92/0x1e0 sock_close+0x1b/0x20 __fput+0x296/0x6e0 ____fput+0x1a/0x20 task_work_run+0x127/0x1a0 do_exit+0x7f9/0x2ce0 ? SYSC_connect+0x212/0x310 ? mm_update_next_owner+0x690/0x690 ? up_read+0x1f/0x40 ? __do_page_fault+0x3c8/0xca0 do_group_exit+0x10d/0x330 ? do_group_exit+0x330/0x330 SyS_exit_group+0x22/0x30 do_syscall_64+0x1e0/0x730 ? trace_hardirqs_off_thunk+0x1a/0x1c entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x7f362e471259 RSP: 002b:00007ffe389abe08 EFLAGS: 00000202 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f362e471259 RDX: 00007f362e471259 RSI: 000000000000002e RDI: 0000000000000000 RBP: 00007ffe389abe30 R08: 0000000000000000 R09: 00007f362e944270 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000400b60 R13: 00007ffe389abf50 R14: 0000000000000000 R15: 0000000000000000 Code: 8d 3c dd a0 8f 64 85 48 89 fa 48 c1 ea 03 80 3c 02 00 75 7b 48 8b 14 dd a0 8f 64 85 4c 89 f6 48 c7 c7 20 85 64 85 e 8 2a 55 14 ff <0f> 0b 83 05 ad 2a 68 04 01 48 83 c4 18 5b 41 5c 41 5d 41 5e 41 Fixes: ee40fb2e1eb5b ("l2tp: protect sock pointer of struct pppol2tp_session with RCU") Signed-off-by: James Chapman <jchapman(a)katalix.com> Signed-off-by: David S. Miller <davem(a)davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- net/l2tp/l2tp_ppp.c | 52 +++++++++++++++++++++++++++------------------------- 1 file changed, 27 insertions(+), 25 deletions(-) --- a/net/l2tp/l2tp_ppp.c +++ b/net/l2tp/l2tp_ppp.c @@ -416,10 +416,28 @@ abort: * Session (and tunnel control) socket create/destroy. *****************************************************************************/ +static void pppol2tp_put_sk(struct rcu_head *head) +{ + struct pppol2tp_session *ps; + + ps = container_of(head, typeof(*ps), rcu); + sock_put(ps->__sk); +} + /* Called by l2tp_core when a session socket is being closed. */ static void pppol2tp_session_close(struct l2tp_session *session) { + struct pppol2tp_session *ps; + + ps = l2tp_session_priv(session); + mutex_lock(&ps->sk_lock); + ps->__sk = rcu_dereference_protected(ps->sk, + lockdep_is_held(&ps->sk_lock)); + RCU_INIT_POINTER(ps->sk, NULL); + if (ps->__sk) + call_rcu(&ps->rcu, pppol2tp_put_sk); + mutex_unlock(&ps->sk_lock); } /* Really kill the session socket. (Called from sock_put() if @@ -439,14 +457,6 @@ static void pppol2tp_session_destruct(st } } -static void pppol2tp_put_sk(struct rcu_head *head) -{ - struct pppol2tp_session *ps; - - ps = container_of(head, typeof(*ps), rcu); - sock_put(ps->__sk); -} - /* Called when the PPPoX socket (session) is closed. */ static int pppol2tp_release(struct socket *sock) @@ -470,26 +480,17 @@ static int pppol2tp_release(struct socke sock_orphan(sk); sock->sk = NULL; + /* If the socket is associated with a session, + * l2tp_session_delete will call pppol2tp_session_close which + * will drop the session's ref on the socket. + */ session = pppol2tp_sock_to_session(sk); - - if (session != NULL) { - struct pppol2tp_session *ps; - + if (session) { l2tp_session_delete(session); - - ps = l2tp_session_priv(session); - mutex_lock(&ps->sk_lock); - ps->__sk = rcu_dereference_protected(ps->sk, - lockdep_is_held(&ps->sk_lock)); - RCU_INIT_POINTER(ps->sk, NULL); - mutex_unlock(&ps->sk_lock); - call_rcu(&ps->rcu, pppol2tp_put_sk); - - /* Rely on the sock_put() call at the end of the function for - * dropping the reference held by pppol2tp_sock_to_session(). - * The last reference will be dropped by pppol2tp_put_sk(). - */ + /* drop the ref obtained by pppol2tp_sock_to_session */ + sock_put(sk); } + release_sock(sk); /* This will delete the session context via @@ -786,6 +787,7 @@ static int pppol2tp_connect(struct socke out_no_ppp: /* This is how we get the session context from the socket. */ + sock_hold(sk); sk->sk_user_data = session; rcu_assign_pointer(ps->sk, sk); mutex_unlock(&ps->sk_lock); Patches currently in stable-queue which might be from jchapman(a)katalix.com are queue-4.15/l2tp-don-t-use-inet_shutdown-on-tunnel-destroy.patch queue-4.15/l2tp-don-t-use-inet_shutdown-on-ppp-session-destroy.patch queue-4.15/l2tp-fix-races-with-tunnel-socket-close.patch queue-4.15/l2tp-fix-race-in-pppol2tp_release-with-session-object-destroy.patch queue-4.15/l2tp-fix-tunnel-lookup-use-after-free-race.patch

7 years, 4 months

1
0
0 0

Patch "l2tp: don't use inet_shutdown on tunnel destroy" has been added to the 4.15-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled l2tp: don't use inet_shutdown on tunnel destroy to the 4.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: l2tp-don-t-use-inet_shutdown-on-tunnel-destroy.patch and it can be found in the queue-4.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. >From foo@baz Tue Mar 6 19:02:56 PST 2018 From: James Chapman <jchapman(a)katalix.com> Date: Fri, 23 Feb 2018 17:45:43 +0000 Subject: l2tp: don't use inet_shutdown on tunnel destroy From: James Chapman <jchapman(a)katalix.com> [ Upstream commit 76a6abdb2513ad4ea0ded55d2c66160491f2e848 ] Previously, if a tunnel was closed, we called inet_shutdown to mark the socket as unconnected such that userspace would get errors and then close the socket. This could race with userspace closing the socket. Instead, leave userspace to close the socket in its own time (our tunnel will be detached anyway). BUG: unable to handle kernel NULL pointer dereference at 00000000000000a0 IP: __lock_acquire+0x263/0x1630 PGD 0 P4D 0 Oops: 0000 [#1] SMP KASAN Modules linked in: CPU: 2 PID: 42 Comm: kworker/u8:2 Not tainted 4.15.0-rc7+ #129 Workqueue: l2tp l2tp_tunnel_del_work RIP: 0010:__lock_acquire+0x263/0x1630 RSP: 0018:ffff88001a37fc70 EFLAGS: 00010002 RAX: 0000000000000001 RBX: 0000000000000088 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff88001a37fd18 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 00000000000076fd R12: 00000000000000a0 R13: ffff88001a3722c0 R14: 0000000000000001 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88001ad00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000000000a0 CR3: 000000001730b000 CR4: 00000000000006e0 Call Trace: ? __lock_acquire+0xc77/0x1630 ? console_trylock+0x11/0xa0 lock_acquire+0x117/0x230 ? lock_sock_nested+0x3a/0xa0 _raw_spin_lock_bh+0x3a/0x50 ? lock_sock_nested+0x3a/0xa0 lock_sock_nested+0x3a/0xa0 inet_shutdown+0x33/0xf0 l2tp_tunnel_del_work+0x60/0xef process_one_work+0x1ea/0x5f0 ? process_one_work+0x162/0x5f0 worker_thread+0x48/0x3e0 ? trace_hardirqs_on+0xd/0x10 kthread+0x108/0x140 ? process_one_work+0x5f0/0x5f0 ? kthread_stop+0x2a0/0x2a0 ret_from_fork+0x24/0x30 Code: 00 41 81 ff ff 1f 00 00 0f 87 7a 13 00 00 45 85 f6 49 8b 85 68 08 00 00 0f 84 ae 03 00 00 c7 44 24 18 00 00 00 00 e9 f0 00 00 00 <49> 81 3c 24 80 93 3f 83 b8 00 00 00 00 44 0f 44 c0 83 fe 01 0f RIP: __lock_acquire+0x263/0x1630 RSP: ffff88001a37fc70 CR2: 00000000000000a0 Fixes: 309795f4bec2d ("l2tp: Add netlink control API for L2TP") Signed-off-by: James Chapman <jchapman(a)katalix.com> Signed-off-by: David S. Miller <davem(a)davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- net/l2tp/l2tp_core.c | 11 ++--------- 1 file changed, 2 insertions(+), 9 deletions(-) --- a/net/l2tp/l2tp_core.c +++ b/net/l2tp/l2tp_core.c @@ -1336,17 +1336,10 @@ static void l2tp_tunnel_del_work(struct sock = sk->sk_socket; - /* If the tunnel socket was created by userspace, then go through the - * inet layer to shut the socket down, and let userspace close it. - * Otherwise, if we created the socket directly within the kernel, use + /* If the tunnel socket was created within the kernel, use * the sk API to release it here. - * In either case the tunnel resources are freed in the socket - * destructor when the tunnel socket goes away. */ - if (tunnel->fd >= 0) { - if (sock) - inet_shutdown(sock, 2); - } else { + if (tunnel->fd < 0) { if (sock) { kernel_sock_shutdown(sock, SHUT_RDWR); sock_release(sock); Patches currently in stable-queue which might be from jchapman(a)katalix.com are queue-4.15/l2tp-don-t-use-inet_shutdown-on-tunnel-destroy.patch queue-4.15/l2tp-don-t-use-inet_shutdown-on-ppp-session-destroy.patch queue-4.15/l2tp-fix-races-with-tunnel-socket-close.patch queue-4.15/l2tp-fix-race-in-pppol2tp_release-with-session-object-destroy.patch queue-4.15/l2tp-fix-tunnel-lookup-use-after-free-race.patch

7 years, 4 months

1
0
0 0

2025

2024

2023

2022

2021

2020

2019

2018

2017

Linux-stable-mirror