| Message ID | 20220425153745.481322-1-maciej.fijalkowski@intel.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | ba3beec2ec1d3b4fd8672ca6e781dac4b3267f6e |
| Delegated to: | BPF |
| Headers | show |
| Series | [bpf] xsk: fix possible crash when multiple sockets are created | expand |
On Tue, Apr 26, 2022 at 12:28 AM Maciej Fijalkowski <maciej.fijalkowski@intel.com> wrote: > > Fix a crash that happens if an Rx only socket is created first, then a > second socket is created that is Tx only and bound to the same umem as > the first socket and also the same netdev and queue_id together with the > XDP_SHARED_UMEM flag. In this specific case, the tx_descs array page > pool was not created by the first socket as it was an Rx only socket. > When the second socket is bound it needs this tx_descs array of this > shared page pool as it has a Tx component, but unfortunately it was > never allocated, leading to a crash. Note that this array is only used > for zero-copy drivers using the batched Tx APIs, currently only ice and > i40e. > > [ 5511.150360] BUG: kernel NULL pointer dereference, address: 0000000000000008 > [ 5511.158419] #PF: supervisor write access in kernel mode > [ 5511.164472] #PF: error_code(0x0002) - not-present page > [ 5511.170416] PGD 0 P4D 0 > [ 5511.173347] Oops: 0002 [#1] PREEMPT SMP PTI > [ 5511.178186] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G E 5.18.0-rc1+ #97 > [ 5511.187245] Hardware name: Intel Corp. GRANTLEY/GRANTLEY, BIOS GRRFCRB1.86B.0276.D07.1605190235 05/19/2016 > [ 5511.198418] RIP: 0010:xsk_tx_peek_release_desc_batch+0x198/0x310 > [ 5511.205375] Code: c0 83 c6 01 84 c2 74 6d 8d 46 ff 23 07 44 89 e1 48 83 c0 14 48 c1 e1 04 48 c1 e0 04 48 03 47 10 4c 01 c1 48 8b 50 08 48 8b 00 <48> 89 51 08 48 89 01 41 80 bd d7 00 00 00 00 75 82 48 8b 19 49 8b > [ 5511.227091] RSP: 0018:ffffc90000003dd0 EFLAGS: 00010246 > [ 5511.233135] RAX: 0000000000000000 RBX: ffff88810c8da600 RCX: 0000000000000000 > [ 5511.241384] RDX: 000000000000003c RSI: 0000000000000001 RDI: ffff888115f555c0 > [ 5511.249634] RBP: ffffc90000003e08 R08: 0000000000000000 R09: ffff889092296b48 > [ 5511.257886] R10: 0000ffffffffffff R11: ffff889092296800 R12: 0000000000000000 > [ 5511.266138] R13: ffff88810c8db500 R14: 0000000000000040 R15: 0000000000000100 > [ 5511.274387] FS: 0000000000000000(0000) GS:ffff88903f800000(0000) knlGS:0000000000000000 > [ 5511.283746] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 5511.290389] CR2: 0000000000000008 CR3: 00000001046e2001 CR4: 00000000003706f0 > [ 5511.298640] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > [ 5511.306892] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > [ 5511.315142] Call Trace: > [ 5511.317972] <IRQ> > [ 5511.320301] ice_xmit_zc+0x68/0x2f0 [ice] > [ 5511.324977] ? ktime_get+0x38/0xa0 > [ 5511.328913] ice_napi_poll+0x7a/0x6a0 [ice] > [ 5511.333784] __napi_poll+0x2c/0x160 > [ 5511.337821] net_rx_action+0xdd/0x200 > [ 5511.342058] __do_softirq+0xe6/0x2dd > [ 5511.346198] irq_exit_rcu+0xb5/0x100 > [ 5511.350339] common_interrupt+0xa4/0xc0 > [ 5511.354777] </IRQ> > [ 5511.357201] <TASK> > [ 5511.359625] asm_common_interrupt+0x1e/0x40 > [ 5511.364466] RIP: 0010:cpuidle_enter_state+0xd2/0x360 > [ 5511.370211] Code: 49 89 c5 0f 1f 44 00 00 31 ff e8 e9 00 7b ff 45 84 ff 74 12 9c 58 f6 c4 02 0f 85 72 02 00 00 31 ff e8 02 0c 80 ff fb 45 85 f6 <0f> 88 11 01 00 00 49 63 c6 4c 2b 2c 24 48 8d 14 40 48 8d 14 90 49 > [ 5511.391921] RSP: 0018:ffffffff82a03e60 EFLAGS: 00000202 > [ 5511.397962] RAX: ffff88903f800000 RBX: 0000000000000001 RCX: 000000000000001f > [ 5511.406214] RDX: 0000000000000000 RSI: ffffffff823400b9 RDI: ffffffff8234c046 > [ 5511.424646] RBP: ffff88810a384800 R08: 000005032a28c046 R09: 0000000000000008 > [ 5511.443233] R10: 000000000000000b R11: 0000000000000006 R12: ffffffff82bcf700 > [ 5511.461922] R13: 000005032a28c046 R14: 0000000000000001 R15: 0000000000000000 > [ 5511.480300] cpuidle_enter+0x29/0x40 > [ 5511.494329] do_idle+0x1c7/0x250 > [ 5511.507610] cpu_startup_entry+0x19/0x20 > [ 5511.521394] start_kernel+0x649/0x66e > [ 5511.534626] secondary_startup_64_no_verify+0xc3/0xcb > [ 5511.549230] </TASK> > > Detect such case during bind() and allocate this memory region via newly > introduced xp_alloc_tx_descs(). Also, use kvcalloc instead of kcalloc as > for other buffer pool allocations, so that it matches the kvfree() from > xp_destroy(). Thank you for this fix Maciej. Acked-by: Magnus Karlsson <magnus.karlsson@intel.com> > Fixes: d1bc532e99be ("i40e: xsk: Move tmp desc array from driver to pool") > Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com> > --- > include/net/xsk_buff_pool.h | 1 + > net/xdp/xsk.c | 13 +++++++++++++ > net/xdp/xsk_buff_pool.c | 16 ++++++++++++---- > 3 files changed, 26 insertions(+), 4 deletions(-) > > diff --git a/include/net/xsk_buff_pool.h b/include/net/xsk_buff_pool.h > index 5554ee75e7da..647722e847b4 100644 > --- a/include/net/xsk_buff_pool.h > +++ b/include/net/xsk_buff_pool.h > @@ -97,6 +97,7 @@ int xp_assign_dev(struct xsk_buff_pool *pool, struct net_device *dev, > u16 queue_id, u16 flags); > int xp_assign_dev_shared(struct xsk_buff_pool *pool, struct xdp_umem *umem, > struct net_device *dev, u16 queue_id); > +int xp_alloc_tx_descs(struct xsk_buff_pool *pool, struct xdp_sock *xs); > void xp_destroy(struct xsk_buff_pool *pool); > void xp_get_pool(struct xsk_buff_pool *pool); > bool xp_put_pool(struct xsk_buff_pool *pool); > diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c > index 040c73345b7c..57afb96c41e8 100644 > --- a/net/xdp/xsk.c > +++ b/net/xdp/xsk.c > @@ -967,6 +967,19 @@ static int xsk_bind(struct socket *sock, struct sockaddr *addr, int addr_len) > > xp_get_pool(umem_xs->pool); > xs->pool = umem_xs->pool; > + > + /* If underlying shared umem was created without Tx > + * ring, allocate Tx descs array that Tx batching API > + * utilizes > + */ > + if (xs->tx && !xs->pool->tx_descs) { > + err = xp_alloc_tx_descs(xs->pool, xs); > + if (err) { > + xp_put_pool(xs->pool); > + sockfd_put(sock); > + goto out_unlock; > + } > + } > } > > xdp_get_umem(umem_xs->umem); > diff --git a/net/xdp/xsk_buff_pool.c b/net/xdp/xsk_buff_pool.c > index af040ffa14ff..87bdd71c7bb6 100644 > --- a/net/xdp/xsk_buff_pool.c > +++ b/net/xdp/xsk_buff_pool.c > @@ -42,6 +42,16 @@ void xp_destroy(struct xsk_buff_pool *pool) > kvfree(pool); > } > > +int xp_alloc_tx_descs(struct xsk_buff_pool *pool, struct xdp_sock *xs) > +{ > + pool->tx_descs = kvcalloc(xs->tx->nentries, sizeof(*pool->tx_descs), > + GFP_KERNEL); > + if (!pool->tx_descs) > + return -ENOMEM; > + > + return 0; > +} > + > struct xsk_buff_pool *xp_create_and_assign_umem(struct xdp_sock *xs, > struct xdp_umem *umem) > { > @@ -59,11 +69,9 @@ struct xsk_buff_pool *xp_create_and_assign_umem(struct xdp_sock *xs, > if (!pool->heads) > goto out; > > - if (xs->tx) { > - pool->tx_descs = kcalloc(xs->tx->nentries, sizeof(*pool->tx_descs), GFP_KERNEL); > - if (!pool->tx_descs) > + if (xs->tx) > + if (xp_alloc_tx_descs(pool, xs)) > goto out; > - } > > pool->chunk_mask = ~((u64)umem->chunk_size - 1); > pool->addrs_cnt = umem->size; > -- > 2.27.0 >
Hello: This patch was applied to bpf/bpf.git (master) by Daniel Borkmann <daniel@iogearbox.net>: On Mon, 25 Apr 2022 17:37:45 +0200 you wrote: > Fix a crash that happens if an Rx only socket is created first, then a > second socket is created that is Tx only and bound to the same umem as > the first socket and also the same netdev and queue_id together with the > XDP_SHARED_UMEM flag. In this specific case, the tx_descs array page > pool was not created by the first socket as it was an Rx only socket. > When the second socket is bound it needs this tx_descs array of this > shared page pool as it has a Tx component, but unfortunately it was > never allocated, leading to a crash. Note that this array is only used > for zero-copy drivers using the batched Tx APIs, currently only ice and > i40e. > > [...] Here is the summary with links: - [bpf] xsk: fix possible crash when multiple sockets are created https://git.kernel.org/bpf/bpf/c/ba3beec2ec1d You are awesome, thank you!
diff --git a/include/net/xsk_buff_pool.h b/include/net/xsk_buff_pool.h index 5554ee75e7da..647722e847b4 100644 --- a/include/net/xsk_buff_pool.h +++ b/include/net/xsk_buff_pool.h @@ -97,6 +97,7 @@ int xp_assign_dev(struct xsk_buff_pool *pool, struct net_device *dev, u16 queue_id, u16 flags); int xp_assign_dev_shared(struct xsk_buff_pool *pool, struct xdp_umem *umem, struct net_device *dev, u16 queue_id); +int xp_alloc_tx_descs(struct xsk_buff_pool *pool, struct xdp_sock *xs); void xp_destroy(struct xsk_buff_pool *pool); void xp_get_pool(struct xsk_buff_pool *pool); bool xp_put_pool(struct xsk_buff_pool *pool); diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c index 040c73345b7c..57afb96c41e8 100644 --- a/net/xdp/xsk.c +++ b/net/xdp/xsk.c @@ -967,6 +967,19 @@ static int xsk_bind(struct socket *sock, struct sockaddr *addr, int addr_len) xp_get_pool(umem_xs->pool); xs->pool = umem_xs->pool; + + /* If underlying shared umem was created without Tx + * ring, allocate Tx descs array that Tx batching API + * utilizes + */ + if (xs->tx && !xs->pool->tx_descs) { + err = xp_alloc_tx_descs(xs->pool, xs); + if (err) { + xp_put_pool(xs->pool); + sockfd_put(sock); + goto out_unlock; + } + } } xdp_get_umem(umem_xs->umem); diff --git a/net/xdp/xsk_buff_pool.c b/net/xdp/xsk_buff_pool.c index af040ffa14ff..87bdd71c7bb6 100644 --- a/net/xdp/xsk_buff_pool.c +++ b/net/xdp/xsk_buff_pool.c @@ -42,6 +42,16 @@ void xp_destroy(struct xsk_buff_pool *pool) kvfree(pool); } +int xp_alloc_tx_descs(struct xsk_buff_pool *pool, struct xdp_sock *xs) +{ + pool->tx_descs = kvcalloc(xs->tx->nentries, sizeof(*pool->tx_descs), + GFP_KERNEL); + if (!pool->tx_descs) + return -ENOMEM; + + return 0; +} + struct xsk_buff_pool *xp_create_and_assign_umem(struct xdp_sock *xs, struct xdp_umem *umem) { @@ -59,11 +69,9 @@ struct xsk_buff_pool *xp_create_and_assign_umem(struct xdp_sock *xs, if (!pool->heads) goto out; - if (xs->tx) { - pool->tx_descs = kcalloc(xs->tx->nentries, sizeof(*pool->tx_descs), GFP_KERNEL); - if (!pool->tx_descs) + if (xs->tx) + if (xp_alloc_tx_descs(pool, xs)) goto out; - } pool->chunk_mask = ~((u64)umem->chunk_size - 1); pool->addrs_cnt = umem->size;
Fix a crash that happens if an Rx only socket is created first, then a second socket is created that is Tx only and bound to the same umem as the first socket and also the same netdev and queue_id together with the XDP_SHARED_UMEM flag. In this specific case, the tx_descs array page pool was not created by the first socket as it was an Rx only socket. When the second socket is bound it needs this tx_descs array of this shared page pool as it has a Tx component, but unfortunately it was never allocated, leading to a crash. Note that this array is only used for zero-copy drivers using the batched Tx APIs, currently only ice and i40e. [ 5511.150360] BUG: kernel NULL pointer dereference, address: 0000000000000008 [ 5511.158419] #PF: supervisor write access in kernel mode [ 5511.164472] #PF: error_code(0x0002) - not-present page [ 5511.170416] PGD 0 P4D 0 [ 5511.173347] Oops: 0002 [#1] PREEMPT SMP PTI [ 5511.178186] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G E 5.18.0-rc1+ #97 [ 5511.187245] Hardware name: Intel Corp. GRANTLEY/GRANTLEY, BIOS GRRFCRB1.86B.0276.D07.1605190235 05/19/2016 [ 5511.198418] RIP: 0010:xsk_tx_peek_release_desc_batch+0x198/0x310 [ 5511.205375] Code: c0 83 c6 01 84 c2 74 6d 8d 46 ff 23 07 44 89 e1 48 83 c0 14 48 c1 e1 04 48 c1 e0 04 48 03 47 10 4c 01 c1 48 8b 50 08 48 8b 00 <48> 89 51 08 48 89 01 41 80 bd d7 00 00 00 00 75 82 48 8b 19 49 8b [ 5511.227091] RSP: 0018:ffffc90000003dd0 EFLAGS: 00010246 [ 5511.233135] RAX: 0000000000000000 RBX: ffff88810c8da600 RCX: 0000000000000000 [ 5511.241384] RDX: 000000000000003c RSI: 0000000000000001 RDI: ffff888115f555c0 [ 5511.249634] RBP: ffffc90000003e08 R08: 0000000000000000 R09: ffff889092296b48 [ 5511.257886] R10: 0000ffffffffffff R11: ffff889092296800 R12: 0000000000000000 [ 5511.266138] R13: ffff88810c8db500 R14: 0000000000000040 R15: 0000000000000100 [ 5511.274387] FS: 0000000000000000(0000) GS:ffff88903f800000(0000) knlGS:0000000000000000 [ 5511.283746] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 5511.290389] CR2: 0000000000000008 CR3: 00000001046e2001 CR4: 00000000003706f0 [ 5511.298640] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 5511.306892] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 5511.315142] Call Trace: [ 5511.317972] <IRQ> [ 5511.320301] ice_xmit_zc+0x68/0x2f0 [ice] [ 5511.324977] ? ktime_get+0x38/0xa0 [ 5511.328913] ice_napi_poll+0x7a/0x6a0 [ice] [ 5511.333784] __napi_poll+0x2c/0x160 [ 5511.337821] net_rx_action+0xdd/0x200 [ 5511.342058] __do_softirq+0xe6/0x2dd [ 5511.346198] irq_exit_rcu+0xb5/0x100 [ 5511.350339] common_interrupt+0xa4/0xc0 [ 5511.354777] </IRQ> [ 5511.357201] <TASK> [ 5511.359625] asm_common_interrupt+0x1e/0x40 [ 5511.364466] RIP: 0010:cpuidle_enter_state+0xd2/0x360 [ 5511.370211] Code: 49 89 c5 0f 1f 44 00 00 31 ff e8 e9 00 7b ff 45 84 ff 74 12 9c 58 f6 c4 02 0f 85 72 02 00 00 31 ff e8 02 0c 80 ff fb 45 85 f6 <0f> 88 11 01 00 00 49 63 c6 4c 2b 2c 24 48 8d 14 40 48 8d 14 90 49 [ 5511.391921] RSP: 0018:ffffffff82a03e60 EFLAGS: 00000202 [ 5511.397962] RAX: ffff88903f800000 RBX: 0000000000000001 RCX: 000000000000001f [ 5511.406214] RDX: 0000000000000000 RSI: ffffffff823400b9 RDI: ffffffff8234c046 [ 5511.424646] RBP: ffff88810a384800 R08: 000005032a28c046 R09: 0000000000000008 [ 5511.443233] R10: 000000000000000b R11: 0000000000000006 R12: ffffffff82bcf700 [ 5511.461922] R13: 000005032a28c046 R14: 0000000000000001 R15: 0000000000000000 [ 5511.480300] cpuidle_enter+0x29/0x40 [ 5511.494329] do_idle+0x1c7/0x250 [ 5511.507610] cpu_startup_entry+0x19/0x20 [ 5511.521394] start_kernel+0x649/0x66e [ 5511.534626] secondary_startup_64_no_verify+0xc3/0xcb [ 5511.549230] </TASK> Detect such case during bind() and allocate this memory region via newly introduced xp_alloc_tx_descs(). Also, use kvcalloc instead of kcalloc as for other buffer pool allocations, so that it matches the kvfree() from xp_destroy(). Fixes: d1bc532e99be ("i40e: xsk: Move tmp desc array from driver to pool") Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com> --- include/net/xsk_buff_pool.h | 1 + net/xdp/xsk.c | 13 +++++++++++++ net/xdp/xsk_buff_pool.c | 16 ++++++++++++---- 3 files changed, 26 insertions(+), 4 deletions(-)