c1a970d06f
After recent refactoring of block offlads infrastructure, indr_dev->block pointer is dereferenced before it is verified to be non-NULL. Example stack trace where this behavior leads to NULL-pointer dereference error when creating vxlan dev on system with mlx5 NIC with offloads enabled: [ 1157.852938] ================================================================== [ 1157.866877] BUG: KASAN: null-ptr-deref in tc_indr_block_ing_cmd.isra.41+0x9c/0x160 [ 1157.880877] Read of size 4 at addr 0000000000000090 by task ip/3829 [ 1157.901637] CPU: 22 PID: 3829 Comm: ip Not tainted 5.2.0-rc6+ #488 [ 1157.914438] Hardware name: Supermicro SYS-2028TP-DECR/X10DRT-P, BIOS 2.0b 03/30/2017 [ 1157.929031] Call Trace: [ 1157.938318] dump_stack+0x9a/0xeb [ 1157.948362] ? tc_indr_block_ing_cmd.isra.41+0x9c/0x160 [ 1157.960262] ? tc_indr_block_ing_cmd.isra.41+0x9c/0x160 [ 1157.972082] __kasan_report+0x176/0x192 [ 1157.982513] ? tc_indr_block_ing_cmd.isra.41+0x9c/0x160 [ 1157.994348] kasan_report+0xe/0x20 [ 1158.004324] tc_indr_block_ing_cmd.isra.41+0x9c/0x160 [ 1158.015950] ? tcf_block_setup+0x430/0x430 [ 1158.026558] ? kasan_unpoison_shadow+0x30/0x40 [ 1158.037464] __tc_indr_block_cb_register+0x5f5/0xf20 [ 1158.049288] ? mlx5e_rep_indr_tc_block_unbind+0xa0/0xa0 [mlx5_core] [ 1158.062344] ? tc_indr_block_dev_put.part.47+0x5c0/0x5c0 [ 1158.074498] ? rdma_roce_rescan_device+0x20/0x20 [ib_core] [ 1158.086580] ? br_device_event+0x98/0x480 [bridge] [ 1158.097870] ? strcmp+0x30/0x50 [ 1158.107578] mlx5e_nic_rep_netdevice_event+0xdd/0x180 [mlx5_core] [ 1158.120212] notifier_call_chain+0x6d/0xa0 [ 1158.130753] register_netdevice+0x6fc/0x7e0 [ 1158.141322] ? netdev_change_features+0xa0/0xa0 [ 1158.152218] ? vxlan_config_apply+0x210/0x310 [vxlan] [ 1158.163593] __vxlan_dev_create+0x2ad/0x520 [vxlan] [ 1158.174770] ? vxlan_changelink+0x490/0x490 [vxlan] [ 1158.185870] ? rcu_read_unlock+0x60/0x60 [vxlan] [ 1158.196798] vxlan_newlink+0x99/0xf0 [vxlan] [ 1158.207303] ? __vxlan_dev_create+0x520/0x520 [vxlan] [ 1158.218601] ? rtnl_create_link+0x3d0/0x450 [ 1158.228900] __rtnl_newlink+0x8a7/0xb00 [ 1158.238701] ? stack_access_ok+0x35/0x80 [ 1158.248450] ? rtnl_link_unregister+0x1a0/0x1a0 [ 1158.258735] ? find_held_lock+0x6d/0xd0 [ 1158.268379] ? is_bpf_text_address+0x67/0xf0 [ 1158.278330] ? lock_acquire+0xc1/0x1f0 [ 1158.287686] ? is_bpf_text_address+0x5/0xf0 [ 1158.297449] ? is_bpf_text_address+0x86/0xf0 [ 1158.307310] ? kernel_text_address+0xec/0x100 [ 1158.317155] ? arch_stack_walk+0x92/0xe0 [ 1158.326497] ? __kernel_text_address+0xe/0x30 [ 1158.336213] ? unwind_get_return_address+0x2f/0x50 [ 1158.346267] ? create_prof_cpu_mask+0x20/0x20 [ 1158.355936] ? arch_stack_walk+0x92/0xe0 [ 1158.365117] ? stack_trace_save+0x8a/0xb0 [ 1158.374272] ? stack_trace_consume_entry+0x80/0x80 [ 1158.384226] ? match_held_lock+0x33/0x210 [ 1158.393216] ? kasan_unpoison_shadow+0x30/0x40 [ 1158.402593] rtnl_newlink+0x53/0x80 [ 1158.410925] rtnetlink_rcv_msg+0x3a5/0x600 [ 1158.419777] ? validate_linkmsg+0x400/0x400 [ 1158.428620] ? find_held_lock+0x6d/0xd0 [ 1158.437117] ? match_held_lock+0x1b/0x210 [ 1158.445760] ? validate_linkmsg+0x400/0x400 [ 1158.454642] netlink_rcv_skb+0xc7/0x1f0 [ 1158.463150] ? netlink_ack+0x470/0x470 [ 1158.471538] ? netlink_deliver_tap+0x1f3/0x5a0 [ 1158.480607] netlink_unicast+0x2ae/0x350 [ 1158.489099] ? netlink_attachskb+0x340/0x340 [ 1158.497935] ? _copy_from_iter_full+0xde/0x3b0 [ 1158.506945] ? __virt_addr_valid+0xb6/0xf0 [ 1158.515578] ? __check_object_size+0x159/0x240 [ 1158.524515] netlink_sendmsg+0x4d3/0x630 [ 1158.532879] ? netlink_unicast+0x350/0x350 [ 1158.541400] ? netlink_unicast+0x350/0x350 [ 1158.549805] sock_sendmsg+0x94/0xa0 [ 1158.557561] ___sys_sendmsg+0x49d/0x570 [ 1158.565625] ? copy_msghdr_from_user+0x210/0x210 [ 1158.574457] ? __fput+0x1e2/0x330 [ 1158.581948] ? __kasan_slab_free+0x130/0x180 [ 1158.590407] ? kmem_cache_free+0xb6/0x2d0 [ 1158.598574] ? mark_lock+0xc7/0x790 [ 1158.606177] ? task_work_run+0xcf/0x100 [ 1158.614165] ? exit_to_usermode_loop+0x102/0x110 [ 1158.622954] ? __lock_acquire+0x963/0x1ee0 [ 1158.631199] ? lockdep_hardirqs_on+0x260/0x260 [ 1158.639777] ? match_held_lock+0x1b/0x210 [ 1158.647918] ? lockdep_hardirqs_on+0x260/0x260 [ 1158.656501] ? match_held_lock+0x1b/0x210 [ 1158.664643] ? __fget_light+0xa6/0xe0 [ 1158.672423] ? __sys_sendmsg+0xd2/0x150 [ 1158.680334] __sys_sendmsg+0xd2/0x150 [ 1158.688063] ? __ia32_sys_shutdown+0x30/0x30 [ 1158.696435] ? lock_downgrade+0x2e0/0x2e0 [ 1158.704541] ? mark_held_locks+0x1a/0x90 [ 1158.712611] ? mark_held_locks+0x1a/0x90 [ 1158.720619] ? do_syscall_64+0x1e/0x2c0 [ 1158.728530] do_syscall_64+0x78/0x2c0 [ 1158.736254] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 1158.745414] RIP: 0033:0x7f62d505cb87 [ 1158.753070] Code: 64 89 02 48 c7 c0 ff ff ff ff eb b9 0f 1f 80 00 00 00 00 8b 05 6a 2b 2c 00 48 63 d2 48 63 ff 85 c0 75 18 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 59 f3 c3 0f 1f 80 00 00[87/1817] 48 89 f3 48 [ 1158.780924] RSP: 002b:00007fffd9832268 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 1158.793204] RAX: ffffffffffffffda RBX: 000000005d26048f RCX: 00007f62d505cb87 [ 1158.805111] RDX: 0000000000000000 RSI: 00007fffd98322d0 RDI: 0000000000000003 [ 1158.817055] RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000006 [ 1158.828987] R10: 00007f62d50ce260 R11: 0000000000000246 R12: 0000000000000001 [ 1158.840909] R13: 000000000067e540 R14: 0000000000000000 R15: 000000000067ed20 [ 1158.852873] ================================================================== Introduce new function tcf_block_non_null_shared() that verifies block pointer before dereferencing it to obtain index. Use the function in tc_indr_block_ing_cmd() to prevent NULL pointer dereference. Fixes: 955bcb6ea0df ("drivers: net: use flow block API") Signed-off-by: Vlad Buslov <vladbu@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.