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authorArend Van Spriel <arend.vanspriel@broadcom.com>2017-03-28 11:11:31 +0300
committerJohannes Berg <johannes.berg@intel.com>2017-03-29 10:11:29 +0300
commitb3ef5520c1eabb56064474043c7c55a1a65b8708 (patch)
tree707c27d1a09e23cace95c2d4896253cb7399fa2f
parentb768b16de58d5e0b1d7c3f936825b25327ced20c (diff)
downloadlinux-b3ef5520c1eabb56064474043c7c55a1a65b8708.tar.xz
cfg80211: check rdev resume callback only for registered wiphy
We got the following use-after-free KASAN report: BUG: KASAN: use-after-free in wiphy_resume+0x591/0x5a0 [cfg80211] at addr ffff8803fc244090 Read of size 8 by task kworker/u16:24/2587 CPU: 6 PID: 2587 Comm: kworker/u16:24 Tainted: G B 4.9.13-debug+ Hardware name: Dell Inc. XPS 15 9550/0N7TVV, BIOS 1.2.19 12/22/2016 Workqueue: events_unbound async_run_entry_fn ffff880425d4f9d8 ffffffffaeedb541 ffff88042b80ef00 ffff8803fc244088 ffff880425d4fa00 ffffffffae84d7a1 ffff880425d4fa98 ffff8803fc244080 ffff88042b80ef00 ffff880425d4fa88 ffffffffae84da3a ffffffffc141f7d9 Call Trace: [<ffffffffaeedb541>] dump_stack+0x85/0xc4 [<ffffffffae84d7a1>] kasan_object_err+0x21/0x70 [<ffffffffae84da3a>] kasan_report_error+0x1fa/0x500 [<ffffffffc141f7d9>] ? cfg80211_bss_age+0x39/0xc0 [cfg80211] [<ffffffffc141f83a>] ? cfg80211_bss_age+0x9a/0xc0 [cfg80211] [<ffffffffae48d46d>] ? trace_hardirqs_on+0xd/0x10 [<ffffffffc13fb1c0>] ? wiphy_suspend+0xc70/0xc70 [cfg80211] [<ffffffffae84def1>] __asan_report_load8_noabort+0x61/0x70 [<ffffffffc13fb100>] ? wiphy_suspend+0xbb0/0xc70 [cfg80211] [<ffffffffc13fb751>] ? wiphy_resume+0x591/0x5a0 [cfg80211] [<ffffffffc13fb751>] wiphy_resume+0x591/0x5a0 [cfg80211] [<ffffffffc13fb1c0>] ? wiphy_suspend+0xc70/0xc70 [cfg80211] [<ffffffffaf3b206e>] dpm_run_callback+0x6e/0x4f0 [<ffffffffaf3b31b2>] device_resume+0x1c2/0x670 [<ffffffffaf3b367d>] async_resume+0x1d/0x50 [<ffffffffae3ee84e>] async_run_entry_fn+0xfe/0x610 [<ffffffffae3d0666>] process_one_work+0x716/0x1a50 [<ffffffffae3d05c9>] ? process_one_work+0x679/0x1a50 [<ffffffffafdd7b6d>] ? _raw_spin_unlock_irq+0x3d/0x60 [<ffffffffae3cff50>] ? pwq_dec_nr_in_flight+0x2b0/0x2b0 [<ffffffffae3d1a80>] worker_thread+0xe0/0x1460 [<ffffffffae3d19a0>] ? process_one_work+0x1a50/0x1a50 [<ffffffffae3e54c2>] kthread+0x222/0x2e0 [<ffffffffae3e52a0>] ? kthread_park+0x80/0x80 [<ffffffffae3e52a0>] ? kthread_park+0x80/0x80 [<ffffffffae3e52a0>] ? kthread_park+0x80/0x80 [<ffffffffafdd86aa>] ret_from_fork+0x2a/0x40 Object at ffff8803fc244088, in cache kmalloc-1024 size: 1024 Allocated: PID = 71 save_stack_trace+0x1b/0x20 save_stack+0x46/0xd0 kasan_kmalloc+0xad/0xe0 kasan_slab_alloc+0x12/0x20 __kmalloc_track_caller+0x134/0x360 kmemdup+0x20/0x50 brcmf_cfg80211_attach+0x10b/0x3a90 [brcmfmac] brcmf_bus_start+0x19a/0x9a0 [brcmfmac] brcmf_pcie_setup+0x1f1a/0x3680 [brcmfmac] brcmf_fw_request_nvram_done+0x44c/0x11b0 [brcmfmac] request_firmware_work_func+0x135/0x280 process_one_work+0x716/0x1a50 worker_thread+0xe0/0x1460 kthread+0x222/0x2e0 ret_from_fork+0x2a/0x40 Freed: PID = 2568 save_stack_trace+0x1b/0x20 save_stack+0x46/0xd0 kasan_slab_free+0x71/0xb0 kfree+0xe8/0x2e0 brcmf_cfg80211_detach+0x62/0xf0 [brcmfmac] brcmf_detach+0x14a/0x2b0 [brcmfmac] brcmf_pcie_remove+0x140/0x5d0 [brcmfmac] brcmf_pcie_pm_leave_D3+0x198/0x2e0 [brcmfmac] pci_pm_resume+0x186/0x220 dpm_run_callback+0x6e/0x4f0 device_resume+0x1c2/0x670 async_resume+0x1d/0x50 async_run_entry_fn+0xfe/0x610 process_one_work+0x716/0x1a50 worker_thread+0xe0/0x1460 kthread+0x222/0x2e0 ret_from_fork+0x2a/0x40 Memory state around the buggy address: ffff8803fc243f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8803fc244000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8803fc244080: fc fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8803fc244100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8803fc244180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb What is happening is that brcmf_pcie_resume() detects a device that is no longer responsive and it decides to unbind resulting in a wiphy_unregister() and wiphy_free() call. Now the wiphy instance remains allocated, because PM needs to call wiphy_resume() for it. However, brcmfmac already does a kfree() for the struct cfg80211_registered_device::ops field. Change the checks in wiphy_resume() to only access the struct cfg80211_registered_device::ops if the wiphy instance is still registered at this time. Cc: stable@vger.kernel.org # 4.10.x, 4.9.x Reported-by: Daniel J Blueman <daniel@quora.org> Reviewed-by: Hante Meuleman <hante.meuleman@broadcom.com> Reviewed-by: Pieter-Paul Giesberts <pieter-paul.giesberts@broadcom.com> Reviewed-by: Franky Lin <franky.lin@broadcom.com> Signed-off-by: Arend van Spriel <arend.vanspriel@broadcom.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
-rw-r--r--net/wireless/sysfs.c10
1 files changed, 4 insertions, 6 deletions
diff --git a/net/wireless/sysfs.c b/net/wireless/sysfs.c
index 16b6b5988be9..570a2b67ca10 100644
--- a/net/wireless/sysfs.c
+++ b/net/wireless/sysfs.c
@@ -132,12 +132,10 @@ static int wiphy_resume(struct device *dev)
/* Age scan results with time spent in suspend */
cfg80211_bss_age(rdev, get_seconds() - rdev->suspend_at);
- if (rdev->ops->resume) {
- rtnl_lock();
- if (rdev->wiphy.registered)
- ret = rdev_resume(rdev);
- rtnl_unlock();
- }
+ rtnl_lock();
+ if (rdev->wiphy.registered && rdev->ops->resume)
+ ret = rdev_resume(rdev);
+ rtnl_unlock();
return ret;
}