Fix a slab-out-of-bounds read that occurs in kmemdup() called from
brcmf_get_assoc_ies().
The bug could occur when assoc_info->req_len, data from a URB provided
by a USB device, is bigger than the size of buffer which is defined as
WL_EXTRA_BUF_MAX.
Add the size check for req_len/resp_len of assoc_info.
Found by a modified version of syzkaller.
[ 46.592467][ T7] ==================================================================
[ 46.594687][ T7] BUG: KASAN: slab-out-of-bounds in kmemdup+0x3e/0x50
[ 46.596572][ T7] Read of size 3014656 at addr ffff888019442000 by task kworker/0:1/7
[ 46.598575][ T7]
[ 46.599157][ T7] CPU: 0 PID: 7 Comm: kworker/0:1 Tainted: G O 5.14.0+ #145
[ 46.601333][ T7] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014
[ 46.604360][ T7] Workqueue: events brcmf_fweh_event_worker
[ 46.605943][ T7] Call Trace:
[ 46.606584][ T7] dump_stack_lvl+0x8e/0xd1
[ 46.607446][ T7] print_address_description.constprop.0.cold+0x93/0x334
[ 46.608610][ T7] ? kmemdup+0x3e/0x50
[ 46.609341][ T7] kasan_report.cold+0x79/0xd5
[ 46.610151][ T7] ? kmemdup+0x3e/0x50
[ 46.610796][ T7] kasan_check_range+0x14e/0x1b0
[ 46.611691][ T7] memcpy+0x20/0x60
[ 46.612323][ T7] kmemdup+0x3e/0x50
[ 46.612987][ T7] brcmf_get_assoc_ies+0x967/0xf60
[ 46.613904][ T7] ? brcmf_notify_vif_event+0x3d0/0x3d0
[ 46.614831][ T7] ? lock_chain_count+0x20/0x20
[ 46.615683][ T7] ? mark_lock.part.0+0xfc/0x2770
[ 46.616552][ T7] ? lock_chain_count+0x20/0x20
[ 46.617409][ T7] ? mark_lock.part.0+0xfc/0x2770
[ 46.618244][ T7] ? lock_chain_count+0x20/0x20
[ 46.619024][ T7] brcmf_bss_connect_done.constprop.0+0x241/0x2e0
[ 46.620019][ T7] ? brcmf_parse_configure_security.isra.0+0x2a0/0x2a0
[ 46.620818][ T7] ? __lock_acquire+0x181f/0x5790
[ 46.621462][ T7] brcmf_notify_connect_status+0x448/0x1950
[ 46.622134][ T7] ? rcu_read_lock_bh_held+0xb0/0xb0
[ 46.622736][ T7] ? brcmf_cfg80211_join_ibss+0x7b0/0x7b0
[ 46.623390][ T7] ? find_held_lock+0x2d/0x110
[ 46.623962][ T7] ? brcmf_fweh_event_worker+0x19f/0xc60
[ 46.624603][ T7] ? mark_held_locks+0x9f/0xe0
[ 46.625145][ T7] ? lockdep_hardirqs_on_prepare+0x3e0/0x3e0
[ 46.625871][ T7] ? brcmf_cfg80211_join_ibss+0x7b0/0x7b0
[ 46.626545][ T7] brcmf_fweh_call_event_handler.isra.0+0x90/0x100
[ 46.627338][ T7] brcmf_fweh_event_worker+0x557/0xc60
[ 46.627962][ T7] ? brcmf_fweh_call_event_handler.isra.0+0x100/0x100
[ 46.628736][ T7] ? rcu_read_lock_sched_held+0xa1/0xd0
[ 46.629396][ T7] ? rcu_read_lock_bh_held+0xb0/0xb0
[ 46.629970][ T7] ? lockdep_hardirqs_on_prepare+0x273/0x3e0
[ 46.630649][ T7] process_one_work+0x92b/0x1460
[ 46.631205][ T7] ? pwq_dec_nr_in_flight+0x330/0x330
[ 46.631821][ T7] ? rwlock_bug.part.0+0x90/0x90
[ 46.632347][ T7] worker_thread+0x95/0xe00
[ 46.632832][ T7] ? __kthread_parkme+0x115/0x1e0
[ 46.633393][ T7] ? process_one_work+0x1460/0x1460
[ 46.633957][ T7] kthread+0x3a1/0x480
[ 46.634369][ T7] ? set_kthread_struct+0x120/0x120
[ 46.634933][ T7] ret_from_fork+0x1f/0x30
[ 46.635431][ T7]
[ 46.635687][ T7] Allocated by task 7:
[ 46.636151][ T7] kasan_save_stack+0x1b/0x40
[ 46.636628][ T7] __kasan_kmalloc+0x7c/0x90
[ 46.637108][ T7] kmem_cache_alloc_trace+0x19e/0x330
[ 46.637696][ T7] brcmf_cfg80211_attach+0x4a0/0x4040
[ 46.638275][ T7] brcmf_attach+0x389/0xd40
[ 46.638739][ T7] brcmf_usb_probe+0x12de/0x1690
[ 46.639279][ T7] usb_probe_interface+0x2aa/0x760
[ 46.639820][ T7] really_probe+0x205/0xb70
[ 46.640342][ T7] __driver_probe_device+0x311/0x4b0
[ 46.640876][ T7] driver_probe_device+0x4e/0x150
[ 46.641445][ T7] __device_attach_driver+0x1cc/0x2a0
[ 46.642000][ T7] bus_for_each_drv+0x156/0x1d0
[ 46.642543][ T7] __device_attach+0x23f/0x3a0
[ 46.643065][ T7] bus_probe_device+0x1da/0x290
[ 46.643644][ T7] device_add+0xb7b/0x1eb0
[ 46.644130][ T7] usb_set_configuration+0xf59/0x16f0
[ 46.644720][ T7] usb_generic_driver_probe+0x82/0xa0
[ 46.645295][ T7] usb_probe_device+0xbb/0x250
[ 46.645786][ T7] really_probe+0x205/0xb70
[ 46.646258][ T7] __driver_probe_device+0x311/0x4b0
[ 46.646804][ T7] driver_probe_device+0x4e/0x150
[ 46.647387][ T7] __device_attach_driver+0x1cc/0x2a0
[ 46.647926][ T7] bus_for_each_drv+0x156/0x1d0
[ 46.648454][ T7] __device_attach+0x23f/0x3a0
[ 46.648939][ T7] bus_probe_device+0x1da/0x290
[ 46.649478][ T7] device_add+0xb7b/0x1eb0
[ 46.649936][ T7] usb_new_device.cold+0x49c/0x1029
[ 46.650526][ T7] hub_event+0x1c98/0x3950
[ 46.650975][ T7] process_one_work+0x92b/0x1460
[ 46.651535][ T7] worker_thread+0x95/0xe00
[ 46.651991][ T7] kthread+0x3a1/0x480
[ 46.652413][ T7] ret_from_fork+0x1f/0x30
[ 46.652885][ T7]
[ 46.653131][ T7] The buggy address belongs to the object at ffff888019442000
[ 46.653131][ T7] which belongs to the cache kmalloc-2k of size 2048
[ 46.654669][ T7] The buggy address is located 0 bytes inside of
[ 46.654669][ T7] 2048-byte region [ffff888019442000, ffff888019442800)
[ 46.656137][ T7] The buggy address belongs to the page:
[ 46.656720][ T7] page:ffffea0000651000 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x19440
[ 46.657792][ T7] head:ffffea0000651000 order:3 compound_mapcount:0 compound_pincount:0
[ 46.658673][ T7] flags: 0x100000000010200(slab|head|node=0|zone=1)
[ 46.659422][ T7] raw: 0100000000010200 0000000000000000 dead000000000122 ffff888100042000
[ 46.660363][ T7] raw: 0000000000000000 0000000000080008 00000001ffffffff 0000000000000000
[ 46.661236][ T7] page dumped because: kasan: bad access detected
[ 46.661956][ T7] page_owner tracks the page as allocated
[ 46.662588][ T7] page last allocated via order 3, migratetype Unmovable, gfp_mask 0x52a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 7, ts 31136961085, free_ts 0
[ 46.664271][ T7] prep_new_page+0x1aa/0x240
[ 46.664763][ T7] get_page_from_freelist+0x159a/0x27c0
[ 46.665340][ T7] __alloc_pages+0x2da/0x6a0
[ 46.665847][ T7] alloc_pages+0xec/0x1e0
[ 46.666308][ T7] allocate_slab+0x380/0x4e0
[ 46.666770][ T7] ___slab_alloc+0x5bc/0x940
[ 46.667264][ T7] __slab_alloc+0x6d/0x80
[ 46.667712][ T7] kmem_cache_alloc_trace+0x30a/0x330
[ 46.668299][ T7] brcmf_usbdev_qinit.constprop.0+0x50/0x470
[ 46.668885][ T7] brcmf_usb_probe+0xc97/0x1690
[ 46.669438][ T7] usb_probe_interface+0x2aa/0x760
[ 46.669988][ T7] really_probe+0x205/0xb70
[ 46.670487][ T7] __driver_probe_device+0x311/0x4b0
[ 46.671031][ T7] driver_probe_device+0x4e/0x150
[ 46.671604][ T7] __device_attach_driver+0x1cc/0x2a0
[ 46.672192][ T7] bus_for_each_drv+0x156/0x1d0
[ 46.672739][ T7] page_owner free stack trace missing
[ 46.673335][ T7]
[ 46.673620][ T7] Memory state around the buggy address:
[ 46.674213][ T7] ffff888019442700: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[ 46.675083][ T7] ffff888019442780: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[ 46.675994][ T7] >ffff888019442800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 46.676875][ T7] ^
[ 46.677323][ T7] ffff888019442880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 46.678190][ T7] ffff888019442900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 46.679052][ T7] ==================================================================
[ 46.679945][ T7] Disabling lock debugging due to kernel taint
[ 46.680725][ T7] Kernel panic - not syncing:
Reviewed-by: Arend van Spriel <arend.vanspriel@xxxxxxxxxxxx>
Signed-off-by: Jisoo Jang <jisoo.jang@xxxxxxxxxxxx>
---
v1->v2: Integrate two size checks
drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
index a9690ec4c850..5a9f713ea703 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
@@ -6164,6 +6164,11 @@ static s32 brcmf_get_assoc_ies(struct brcmf_cfg80211_info *cfg,
(struct brcmf_cfg80211_assoc_ielen_le *)cfg->extra_buf;
req_len = le32_to_cpu(assoc_info->req_len);
resp_len = le32_to_cpu(assoc_info->resp_len);
+ if (req_len > WL_EXTRA_BUF_MAX || resp_len > WL_EXTRA_BUF_MAX) {
+ bphy_err(drvr, "invalid lengths in assoc info: req %u resp %u\n",
+ req_len, resp_len);
+ return -EINVAL;
+ }
if (req_len) {
err = brcmf_fil_iovar_data_get(ifp, "assoc_req_ies",
cfg->extra_buf,
--
2.25.1
