RE: [Intel-wired-lan] [PATCH net v5 1/2] iavf: Fix use-after-free in free_netdev

[Romanowski, Rafal]

> -----Original Message-----
> From: Intel-wired-lan <intel-wired-lan-bounces@xxxxxxxxxx> On Behalf Of
> Leon Romanovsky
> Sent: wtorek, 9 maja 2023 15:40
> To: Ding, Hui <dinghui@xxxxxxxxxxxxxx>
> Cc: pengdonglin@xxxxxxxxxxxxxx; keescook@xxxxxxxxxxxx;
> gregory.v.rose@xxxxxxxxx; Nguyen, Anthony L
> <anthony.l.nguyen@xxxxxxxxx>; Williams, Mitch A
> <mitch.a.williams@xxxxxxxxx>; Brandeburg, Jesse
> <jesse.brandeburg@xxxxxxxxx>; huangcun@xxxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx; grzegorzx.szczurek@xxxxxxxxx;
> edumazet@xxxxxxxxxx; Kubiak, Michal <michal.kubiak@xxxxxxxxx>; intel-
> wired-lan@xxxxxxxxxxxxxxxx; jeffrey.t.kirsher@xxxxxxxxx;
> simon.horman@xxxxxxxxxxxx; kuba@xxxxxxxxxx; netdev@xxxxxxxxxxxxxxx;
> pabeni@xxxxxxxxxx; davem@xxxxxxxxxxxxx; linux-
> hardening@xxxxxxxxxxxxxxx
> Subject: Re: [Intel-wired-lan] [PATCH net v5 1/2] iavf: Fix use-after-free in
> free_netdev
> 
> On Tue, May 09, 2023 at 07:11:47PM +0800, Ding Hui wrote:
> > We do netif_napi_add() for all allocated q_vectors[], but potentially
> > do netif_napi_del() for part of them, then kfree q_vectors and leave
> > invalid pointers at dev->napi_list.
> >
> > Reproducer:
> >
> >   [root@host ~]# cat repro.sh
> >   #!/bin/bash
> >
> >   pf_dbsf="0000:41:00.0"
> >   vf0_dbsf="0000:41:02.0"
> >   g_pids=()
> >
> >   function do_set_numvf()
> >   {
> >       echo 2 >/sys/bus/pci/devices/${pf_dbsf}/sriov_numvfs
> >       sleep $((RANDOM%3+1))
> >       echo 0 >/sys/bus/pci/devices/${pf_dbsf}/sriov_numvfs
> >       sleep $((RANDOM%3+1))
> >   }
> >
> >   function do_set_channel()
> >   {
> >       local nic=$(ls -1 --indicator-style=none
> /sys/bus/pci/devices/${vf0_dbsf}/net/)
> >       [ -z "$nic" ] && { sleep $((RANDOM%3)) ; return 1; }
> >       ifconfig $nic 192.168.18.5 netmask 255.255.255.0
> >       ifconfig $nic up
> >       ethtool -L $nic combined 1
> >       ethtool -L $nic combined 4
> >       sleep $((RANDOM%3))
> >   }
> >
> >   function on_exit()
> >   {
> >       local pid
> >       for pid in "${g_pids[@]}"; do
> >           kill -0 "$pid" &>/dev/null && kill "$pid" &>/dev/null
> >       done
> >       g_pids=()
> >   }
> >
> >   trap "on_exit; exit" EXIT
> >
> >   while :; do do_set_numvf ; done &
> >   g_pids+=($!)
> >   while :; do do_set_channel ; done &
> >   g_pids+=($!)
> >
> >   wait
> >
> > Result:
> >
> > [ 4093.900222]
> >
> ==========================================================
> ========
> > [ 4093.900230] BUG: KASAN: use-after-free in free_netdev+0x308/0x390 [
> > 4093.900232] Read of size 8 at addr ffff88b4dc145640 by task
> > repro.sh/6699 [ 4093.900233]
> > [ 4093.900236] CPU: 10 PID: 6699 Comm: repro.sh Kdump: loaded Tainted:
> G           O     --------- -t - 4.18.0 #1
> > [ 4093.900238] Hardware name: Powerleader PR2008AL/H12DSi-N6, BIOS
> 2.0
> > 04/09/2021 [ 4093.900239] Call Trace:
> > [ 4093.900244]  dump_stack+0x71/0xab
> > [ 4093.900249]  print_address_description+0x6b/0x290
> > [ 4093.900251]  ? free_netdev+0x308/0x390 [ 4093.900252]
> > kasan_report+0x14a/0x2b0 [ 4093.900254]  free_netdev+0x308/0x390 [
> > 4093.900261]  iavf_remove+0x825/0xd20 [iavf] [ 4093.900265]
> > pci_device_remove+0xa8/0x1f0 [ 4093.900268]
> > device_release_driver_internal+0x1c6/0x460
> > [ 4093.900271]  pci_stop_bus_device+0x101/0x150 [ 4093.900273]
> > pci_stop_and_remove_bus_device+0xe/0x20
> > [ 4093.900275]  pci_iov_remove_virtfn+0x187/0x420 [ 4093.900277]  ?
> > pci_iov_add_virtfn+0xe10/0xe10 [ 4093.900278]  ?
> > pci_get_subsys+0x90/0x90 [ 4093.900280]  sriov_disable+0xed/0x3e0 [
> > 4093.900282]  ? bus_find_device+0x12d/0x1a0 [ 4093.900290]
> > i40e_free_vfs+0x754/0x1210 [i40e] [ 4093.900298]  ?
> > i40e_reset_all_vfs+0x880/0x880 [i40e] [ 4093.900299]  ?
> > pci_get_device+0x7c/0x90 [ 4093.900300]  ? pci_get_subsys+0x90/0x90 [
> > 4093.900306]  ? pci_vfs_assigned.part.7+0x144/0x210
> > [ 4093.900309]  ? __mutex_lock_slowpath+0x10/0x10 [ 4093.900315]
> > i40e_pci_sriov_configure+0x1fa/0x2e0 [i40e] [ 4093.900318]
> > sriov_numvfs_store+0x214/0x290 [ 4093.900320]  ?
> > sriov_totalvfs_show+0x30/0x30 [ 4093.900321]  ?
> > __mutex_lock_slowpath+0x10/0x10 [ 4093.900323]  ?
> > __check_object_size+0x15a/0x350 [ 4093.900326]
> > kernfs_fop_write+0x280/0x3f0 [ 4093.900329]  vfs_write+0x145/0x440 [
> > 4093.900330]  ksys_write+0xab/0x160 [ 4093.900332]  ?
> > __ia32_sys_read+0xb0/0xb0 [ 4093.900334]  ? fput_many+0x1a/0x120 [
> > 4093.900335]  ? filp_close+0xf0/0x130 [ 4093.900338]
> > do_syscall_64+0xa0/0x370 [ 4093.900339]  ? page_fault+0x8/0x30 [
> > 4093.900341]  entry_SYSCALL_64_after_hwframe+0x65/0xca
> > [ 4093.900357] RIP: 0033:0x7f16ad4d22c0 [ 4093.900359] Code: 73 01 c3
> > 48 8b 0d d8 cb 2c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00
> > 83 3d 89 24 2d 00 00 75 10 b8 01 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73
> > 31 c3 48 83 ec 08 e8 fe dd 01 00 48 89 04 24 [ 4093.900360] RSP:
> > 002b:00007ffd6491b7f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 [
> > 4093.900362] RAX: ffffffffffffffda RBX: 0000000000000002 RCX:
> > 00007f16ad4d22c0 [ 4093.900363] RDX: 0000000000000002 RSI:
> > 0000000001a41408 RDI: 0000000000000001 [ 4093.900364] RBP:
> > 0000000001a41408 R08: 00007f16ad7a1780 R09: 00007f16ae1f2700 [
> > 4093.900364] R10: 0000000000000001 R11: 0000000000000246 R12:
> 0000000000000002 [ 4093.900365] R13: 0000000000000001 R14:
> 00007f16ad7a0620 R15: 0000000000000001 [ 4093.900367] [ 4093.900368]
> Allocated by task 820:
> > [ 4093.900371]  kasan_kmalloc+0xa6/0xd0 [ 4093.900373]
> > __kmalloc+0xfb/0x200 [ 4093.900376]
> > iavf_init_interrupt_scheme+0x63b/0x1320 [iavf] [ 4093.900380]
> > iavf_watchdog_task+0x3d51/0x52c0 [iavf] [ 4093.900382]
> > process_one_work+0x56a/0x11f0 [ 4093.900383]
> worker_thread+0x8f/0xf40
> > [ 4093.900384]  kthread+0x2a0/0x390 [ 4093.900385]
> > ret_from_fork+0x1f/0x40 [ 4093.900387]  0xffffffffffffffff [
> > 4093.900387] [ 4093.900388] Freed by task 6699:
> > [ 4093.900390]  __kasan_slab_free+0x137/0x190 [ 4093.900391]
> > kfree+0x8b/0x1b0 [ 4093.900394]  iavf_free_q_vectors+0x11d/0x1a0
> > [iavf] [ 4093.900397]  iavf_remove+0x35a/0xd20 [iavf] [ 4093.900399]
> > pci_device_remove+0xa8/0x1f0 [ 4093.900400]
> > device_release_driver_internal+0x1c6/0x460
> > [ 4093.900401]  pci_stop_bus_device+0x101/0x150 [ 4093.900402]
> > pci_stop_and_remove_bus_device+0xe/0x20
> > [ 4093.900403]  pci_iov_remove_virtfn+0x187/0x420 [ 4093.900404]
> > sriov_disable+0xed/0x3e0 [ 4093.900409]  i40e_free_vfs+0x754/0x1210
> > [i40e] [ 4093.900415]  i40e_pci_sriov_configure+0x1fa/0x2e0 [i40e] [
> > 4093.900416]  sriov_numvfs_store+0x214/0x290 [ 4093.900417]
> > kernfs_fop_write+0x280/0x3f0 [ 4093.900418]  vfs_write+0x145/0x440 [
> > 4093.900419]  ksys_write+0xab/0x160 [ 4093.900420]
> > do_syscall_64+0xa0/0x370 [ 4093.900421]
> > entry_SYSCALL_64_after_hwframe+0x65/0xca
> > [ 4093.900422]  0xffffffffffffffff
> > [ 4093.900422]
> > [ 4093.900424] The buggy address belongs to the object at
> ffff88b4dc144200
> >                 which belongs to the cache kmalloc-8k of size 8192 [
> > 4093.900425] The buggy address is located 5184 bytes inside of
> >                 8192-byte region [ffff88b4dc144200, ffff88b4dc146200)
> > [ 4093.900425] The buggy address belongs to the page:
> > [ 4093.900427] page:ffffea00d3705000 refcount:1 mapcount:0
> > mapping:ffff88bf04415c80 index:0x0 compound_mapcount: 0 [
> 4093.900430]
> > flags: 0x10000000008100(slab|head) [ 4093.900433] raw:
> > 0010000000008100 dead000000000100 dead000000000200 ffff88bf04415c80
> [
> > 4093.900434] raw: 0000000000000000 0000000000030003 00000001ffffffff
> > 0000000000000000 [ 4093.900434] page dumped because: kasan: bad access
> > detected [ 4093.900435] [ 4093.900435] Memory state around the buggy
> address:
> > [ 4093.900436]  ffff88b4dc145500: fb fb fb fb fb fb fb fb fb fb fb fb
> > fb fb fb fb [ 4093.900437]  ffff88b4dc145580: fb fb fb fb fb fb fb fb
> > fb fb fb fb fb fb fb fb [ 4093.900438] >ffff88b4dc145600: fb fb fb fb fb fb fb
> fb fb fb fb fb fb fb fb fb
> > [ 4093.900438]                                            ^
> > [ 4093.900439]  ffff88b4dc145680: fb fb fb fb fb fb fb fb fb fb fb fb
> > fb fb fb fb [ 4093.900440]  ffff88b4dc145700: fb fb fb fb fb fb fb fb
> > fb fb fb fb fb fb fb fb [ 4093.900440]
> >
> ==========================================================
> ========
> >
> > Although the patch #2 (of 2) can avoid the issuse triggered by this
> > repro.sh, there still are other potential risks that if
> > num_active_queues is changed to less than allocated q_vectors[] by
> > unexpected, the mismatched netif_napi_add/del() can also cause UAF.
> >
> > Since we actually call netif_napi_add() for all allocated q_vectors
> > unconditionally in iavf_alloc_q_vectors(), so we should fix it by
> > letting netif_napi_del() match to netif_napi_add().
> >
> > Fixes: 5eae00c57f5e ("i40evf: main driver core")
> > Signed-off-by: Ding Hui <dinghui@xxxxxxxxxxxxxx>
> > Cc: Donglin Peng <pengdonglin@xxxxxxxxxxxxxx>
> > Cc: Huang Cun <huangcun@xxxxxxxxxxxxxx>
> > Reviewed-by: Simon Horman <simon.horman@xxxxxxxxxxxx>
> > Reviewed-by: Michal Kubiak <michal.kubiak@xxxxxxxxx>
> > Reviewed-by: Madhu Chittim <madhu.chittim@xxxxxxxxx>
> > ---
> > v4 to v5:
> >   - no changes
> >
> > v3 to v4:
> >   - fix typo in commit message
> >
> > v2 to v3:
> >   - fix review tag
> >
> > v1 to v2:
> >   - add Fixes: tag
> >   - add reproduction script
> >   - update commit message
> >
> > ---
> >  drivers/net/ethernet/intel/iavf/iavf_main.c | 6 +-----
> >  1 file changed, 1 insertion(+), 5 deletions(-)
> >
> 
> Thanks,
> Reviewed-by: Leon Romanovsky <leonro@xxxxxxxxxx>
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Tested-by: Rafal Romanowski <rafal.romanowski@xxxxxxxxx>